1

Roles of Transportation Management Centers in 

Incident Management on 

Managed Lanes

FHWA-HOP-14-022 December 2014
Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation 

in the interest of information exchange. The U.S. Government assumes no liability for the use of 

the information contained in this document. 

The U.S. Government does not endorse products or manufacturers. Trademarks or 

manufacturers’ names appear in this report only because they are considered essential to the 

objective of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve 

Government, industry, and the public in a manner that promotes public understanding. Standards 

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ensure continuous quality improvement.
1. Report No.

FHWA-HOP-14-022 

2. Government Accession

No. 

3. Recipient's Catalog No.

4. Title and Subtitle

Roles of Transportation Management Centers in Incident Management on 

Managed Lanes 

5. Report Date

December 2014 

6. Performing Organization Code

7.Author(s)

Michael J. Tantillo, Edwin Roberts, and Uzoamaka Mangar 

8. Performing Organization Report No.

9. Performing Organization Name and Address

Vanasse Hangen Brustlin, Inc (VHB) 

8300 Boone Blvd., Suite 700 

Vienna, VA 22182-2626 

10. Work Unit No.

11. Contract or Grant No.

DTFH61-12-D-00039 

12. Sponsoring Agency Name and Address

Federal Highway Administration Office of Operations 

1200 New Jersey Ave., SE 

Washington, DC 20590

13. Type of Report and Period

14. Sponsoring Agency Code

FHWA

15. Supplementary Notes

The contract manager for this report was Jimmy Chu. 

16. Abstract

This guidebook examines traffic incident management practices that are implemented by transportation management 

centers on managed lanes. The document examines the unique operating environment of managed lanes from an incident 

management perspective. The roles of the transportation management center in the managed lane environment are 

discussed in terms of incident preparedness and real-time incident management activities and support. A comparison of 

best practices for eight case studies is presented, and an in-depth analysis of the role of the transportation management 

center in incident management is presented for three of the managed lane facilities examined in the case studies. 

17. Key Words:

transportation management center, incident 

management, managed lanes 

18. Distribution Statement

No restrictions. 

19. Security Classif. (of this report)

Unclassified 

20. Security Classif. (of this

page) Unclassified 

21. No. of Pages

 101 

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed pages authorized 

Form DOT F 1700.7 (8-72) 
ROLES OF TRANSPORTATION MANAGEMENT CENTERS IN INCIDENT MANAGEMENT ON MANAGED LANES

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TABLE OF CONTENTS

TABLE OF CONTENTS

Executive Summary����������������������������������������������������������������������������������������������������������������������1

Chapter 1—Introduction and Background ��������������������������������������������������������������������������������7

1.1	 Definition of Managed Lanes��������������������������������������������������������������������������������������������8

1.2	 Access to Managed Lanes�������������������������������������������������������������������������������������������������9

1.3	 Physical Design of Managed Lanes ��������������������������������������������������������������������������������10

1.4	 Importance of TIM in Managed Lanes����������������������������������������������������������������������������13

1.5	 TMC Operations��������������������������������������������������������������������������������������������������������������14

Chapter 2—Unique Aspects of TIM in Managed Lanes���������������������������������������������������������17

2.1	 Need for Interagency Coordination���������������������������������������������������������������������������������17

2.2	 Enhanced Traffic Management System Capabilities�������������������������������������������������������18

2.3	 Enhanced Operational Control ����������������������������������������������������������������������������������������19

2.4	 Physical Access Constraints��������������������������������������������������������������������������������������������23

2.5	 Financial Considerations�������������������������������������������������������������������������������������������������24

Chapter 3—TMC Role in the Managed Lane Environment—Preparedness ����������������������27

3.1	 Technology and Communications�����������������������������������������������������������������������������������28

3.2	 Interagency Relations and Coordination �������������������������������������������������������������������������30

3.3	 Managed Lane Enforcement Patrols �������������������������������������������������������������������������������33

3.4	 TMC Resources���������������������������������������������������������������������������������������������������������������35

3.5	 TMC Involvement in Managed Lane Design �����������������������������������������������������������������35

3.6	 TMC Involvement in Operational Planning��������������������������������������������������������������������38

3.7	 TMC Preparedness Checklists�����������������������������������������������������������������������������������������40

Chapter 4—TMC Role in the Managed Lane Environment—Real Time TIM

Response Activities and Support��������������������������������������������������������������������������43

4.1	 Shared Operations Responsibilities���������������������������������������������������������������������������������43

4.2	 TIM Process ��������������������������������������������������������������������������������������������������������������������46

4.3	 Incident Detection and Verification ��������������������������������������������������������������������������������47

4.4	 Incident Response������������������������������������������������������������������������������������������������������������49

4.5	 Scene Management and Traffic Control��������������������������������������������������������������������������51

4.6	 Clearance and Recovery��������������������������������������������������������������������������������������������������57

4.7	 System and Corridor Management����������������������������������������������������������������������������������58

4.8	 TIM Response and Support Checklist�����������������������������������������������������������������������������60
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Chapter 5—Case Studies������������������������������������������������������������������������������������������������������������63

5.1	 Case Study 1

Minnesota’s I-35W HOT/Priced Dynamic Shoulder Lane and ATM System�����������������67

5.2	 Case Study 2

Houston’s Katy Freeway Managed Lanes and Interagency Coordination ����������������������73

5.3	 Case Study 3

Fairfax County, Virginia’s I-495 Express Lanes and Private Sector Operators ��������������79

Chapter 6—Conclusions�������������������������������������������������������������������������������������������������������������85

Glossary of Terms �����������������������������������������������������������������������������������������������������������������������87

Acknowledgements ���������������������������������������������������������������������������������������������������������������������93
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LIST OF FIGURES

Figure 1	 Photo. Uncongested managed lanes adjacent to congested general purpose lanes����� 7

Figure 2	 Photo. Managed lanes function as a “freeway within a freeway” ������������������������������� 8

Figure 3	 Illustration. MUTCD sign showing HOV lanes have a minimum

vehicle occupancy requirement ����������������������������������������������������������������������������������� 9

Figure 4	 Illustration. MUTCD sign showing ETLs with congestion

pricing have variable tolls�������������������������������������������������������������������������������������������� 9

Figure 5	 Illustration. MUTCD sign showing HOT lanes are ETLs where

HOVs do not pay for access�������������������������������������������������������������������������������������� 10

Figure 6	 Photo. Part-time shoulder lane����������������������������������������������������������������������������������� 11

Figure 7	 Photo. Managed lane separated from general purpose lanes with painted buffer ����� 11

Figure 8	 Photo. The left lane is a continuous access HOV lane ���������������������������������������������� 11

Figure 9	 Photo. Invisible electronic barrier using toll tag readers and cameras���������������������� 11

Figure 10	 Photo. Plastic post barrier...........................................................................................12

Figure 11	 Photo. Permanent physical barrier creates two separate roadways............................12

Figure 12	 Photo. Zipper barrier and mobile machine ����������������������������������������������������������������12

Figure 13	 Photo. An incident in a managed lane can inconvenience many

people, such as transit riders, since vehicle occupancies are high.............................13

Figure 14	 Photo. Inside of the New Jersey Statewide Transportation

Management Center....................................................................................................15

Figure 15	 Photo. The 91 Express Lanes in Orange County, CA are operated by a

different agency than the adjacent general purpose lanes..........................................17

Figure 16	 Photo. Managed lanes typically have extensive deployments of

ITS equipment, such as these CCTV cameras����������������������������������������������������������� 18

Figure 17	 Photo. Some managed lanes can be remotely closed from the TMC,

such as this reversible facility������������������������������������������������������������������������������������ 19

Figure 18	 Illustration. MUTCD sign showing variable speed limits����������������������������������������� 20

Figure 19	 Photo. Managed lanes can suspend all eligibility requirements

and allow all traffic ���������������������������������������������������������������������������������������������������� 22
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Figure 20	 Photo. Plastic “candlestick” posts can be moved to provide

emergency access to managed lanes�������������������������������������������������������������������������� 24

Figure 21	 Photo. Suspension of tolls in managed lanes is rare due to concerns

	 over revenue loss, but can be implemented during large

incidents, such as during this region-wide snow emergency������������������������������������� 25

Figure 22	 Photo. Dispatchers working inside a TMC must make special

preparations to handle incidents within managed lanes �������������������������������������������� 27

Figure 23	 Photo. A TMC will have many technology and communications

resources, such as the ability to display travel times captured

from roadway detectors on a DMS���������������������������������������������������������������������������� 28

Figure 24	 Photo. Safety service patrol vehicle �������������������������������������������������������������������������� 34

Figure 25	 Photo. Enforcement area provides enforcement and service

patrol vehicles a safe refuge from traffic ������������������������������������������������������������������� 36

Figure 26	 Checklist. TMC Planning Preparedness Checklist���������������������������������������������������� 41

Figure 27	 Checklist. TMC Preparedness—Operator’s Checklist ���������������������������������������������� 42

Figure 28	 Photo. Traffic incident and response�������������������������������������������������������������������������� 43

Figure 29	 Photo. The I-495 Express Lanes in Fairfax County, VA are privately operated

while the general purpose lanes are operated by the state DOT, yet they

must function as a unified transportation system������������������������������������������������������� 44

Figure 30	 Chart. Stages of the TIM process ������������������������������������������������������������������������������ 47

Figure 31	 Verification of the exact location of the incident is important

when there is physical separation between lanes....................................................... 47

Figure 32	 Photo. These New York State DOT HELP trucks have onboard cameras

linked to the TMC to provide realtime incident information..................................... 50

Figure 33	 Photo. Pre-positioned service vehicles or service vehicles on a roving

patrol can monitor the managed lanes and provide quick

response if an incident occurs.....................................................................................50

Figure 34	 Photo. Incident scene management using DMS messages.........................................52

Figure 35	 Illustration. Incident zone traffic control to create a safe work area ������������������������� 52

Figure 36	 Photo. Some managed lanes can adjust vehicle occupancy thresholds

or suspend access by tolled vehicles�������������������������������������������������������������������������� 54
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Figure 37	 Photo. Priced managed lanes can increase the toll prices to

reduce demand����������������������������������������������������������������������������������������������������������� 55

Figure 38	 Photo. Some managed lanes have signs and gates that can be

used to quickly close the lanes during an incident ���������������������������������������������������� 55

Figure 39	 Photo. Effective clearance may be challenging in managed lanes

with no shoulders and physical barriers, such as this zipper

lane in New York City ����������������������������������������������������������������������������������������������� 56

Figure 40	 Photo. Use of lane control signals to close lanes on the I-35W PDSL

in Minneapolis����������������������������������������������������������������������������������������������������������� 58

Figure 41	 Photo. Signs displaying travel times via private vehicle and public

transit can encourage modal shift during incidents��������������������������������������������������� 58

Figure 42	 Checklist. TMC Real Time Response Activities and Support Checklist������������������� 61

Figure 43	 Illustration. I-35W PDSL HOT lane�������������������������������������������������������������������������� 69

Figure 44	 Photo. ATM System on I-35W in Minneapolis ��������������������������������������������������������� 71

Figure 45	 Photo. I-10 Katy Freeway managed lanes with plastic post barrier

and full shoulders on either side �������������������������������������������������������������������������������� 74

Figure 46	 Photo. The Katy managed lanes (or Katy Tollway) operate as HOT

during peak hours and ETL at other times, and have a

maximum possible toll����������������������������������������������������������������������������������������������� 75

Figure 47	 Photo. I-495 Express Lanes on the Capital Beltway in

Fairfax County, VA, near Washington, DC���������������������������������������������������������������� 79

Figure 48	 Photo. The I-495 Express Lanes are operated by a private firm and are

separated from the publicly owned and heavily congested general

purpose lanes by a 4 foot buffer with a plastic post barrier��������������������������������������� 81

Figure 49	 Chart. Response to unplanned incidents along I-495 ������������������������������������������������ 82

LIST OF TABLES

Table 1		 TIM partners, agency roles and responsibilities ������������������������������������������������������� 31

Table 2		 TIM Best Practices Comparison for Eight Managed Lane Facilities������������������������ 64
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ROLES OF TRANSPORTATION MANAGEMENT CENTERS IN INCIDENT MANAGEMENT ON MANAGED LANES

EXECUTIVE SUMMARY

EXECUTIVE SUMMARY

Introduction and Background

Managed lanes are becoming an increasingly popular strategy to address traffic congestion, 

because they efficiently carry large numbers of people within a small amount of roadway space. 

This guidebook examines traffic incident management (TIM) practices that are implemented by 

transportation management centers (TMCs) and evaluates their use in the unique operating environment of managed lanes. This guidebook provides a framework for successful development 

and implementation of a TIM program using a TMC in the managed lane environment. It can be 

of use to planners developing new managed lane facilities, and transportation professionals who 

oversee existing managed lane facilities looking to optimize the use of their TMC and make their 

TIM program as effective as possible. 

Managed lanes function as a “freeway within a freeway” and employ proactively implemented 

operating strategies in response to changing conditions. The goal is to have the managed lanes 

operate efficiently and reliably, with little or no congestion, to provide a higher level of service 

to eligible vehicles. Vehicle eligibility can be based on the type of vehicle (bus, truck, transit 

vehicle), the number of occupants in the vehicle, or the willingness to pay a toll. The most 

common types of managed lanes include High Occupancy Vehicle (HOV) lanes, Express Toll 

lanes (ETLs), and High Occupancy/Toll (HOT) lanes. The latter two categories utilize congestion 

pricing with variable toll rates that rise and fall based on traffic demand to “price out” low value 

trips and maintain the higher level of service in the managed lane. 

Efficient TIM is critical for the success of a managed lane facility. Incidents that occur in 

managed lanes will affect greater numbers of people, as vehicle occupancy rates are typically 

higher in managed lanes than other lanes. The users affected by an incident in a managed lane 

are typically those road users with the highest priority within the transportation network, such 

as HOVs or transit vehicles. The reliability of the managed lane depends on quick clearance of 

incidents. Otherwise, operators cannot provide reliable service to users, which may limit the 

effectiveness of the facility.

Unique Aspects of TIM in Managed Lanes

The TMC will typically have unique capabilities and functionalities for the managed lane system 

since the managed lanes must respond to changing traffic conditions. Therefore the TMC’s 

ability to detect an incident is enhanced, and the amount of operational control that a TMC has 

over a managed lane is also enhanced through the use of Intelligent Transportation Systems 

(ITS). Financial considerations are important during TIM in priced managed lanes, as there will 

be revenue loss if tolls are suspended or the facility is closed. 

The method of separation between a managed lane and the parallel general purpose lanes can 

present challenges during TIM for responder access and diversions. Several facilities use permanent physical barriers which create an access limitation. Others use flexible posts or movable 

barriers that can be crossed during an incident. Many managed lanes rely solely on driver 

compliance with painted lines and buffer zones and have no physical separation. 
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TMC Role in the Managed Lane Environment—TMC Preparedness

The TMC role in TIM in managed lanes is generally similar to its role on other highway facilities; however the TMC must be aware of the additional challenges when an incident occurs 

within a managed lane environment. A TMC will typically have access to robust technology and 

communications capabilities. These capabilities can detect incidents, enhance necessary interagency coordination, and collect and disseminate data to stakeholders. Data sharing agreements 

and communications protocols have been established to facilitate this sharing of information 

along the managed lanes corridor. Interagency coordination protocols and agreements are in 

place between all TIM stakeholders. These agreements will involve other transportation agencies 

operating along the managed lane corridor in addition to response agencies, and should clearly 

define each agency’s responsibilities. As part of the agreement, a designated point of contact at 

each agency for planning-related matters should be identified, and a communication protocol 

with multiple points of contact at each agency established for real-time operational matters. The 

goals of such agreements are effective coordination among all agencies, proper dissemination of 

information, TIM, and transportation system management during an incident.

A TMC or managed lane operator will typically have enforcement agreements with local law 

enforcement agencies. These enforcement agreements will be focused on enforcing compliance 

with access rules and enhancing operation of the managed lanes under normal circumstances. 

These law enforcement agencies may also be responsible for roadway service patrols, and will 

also typically be the first responders at the scene of an incident. Therefore, enforcement agreements should not only account for normal circumstances but should also account for the agency’s 

role during an incident. Procedures for TIM in the operating environment of the TMC, and 

defining the appropriate level of enforcement should be part of the agreement. A TMC will have 

many other resources available to support TIM in the managed lanes. In priced managed lanes, 

toll revenue may be used to support the operation of the TMC and its activities. A portion of 

these funds and resources could be allocated to further the goals of the managed lane and provide 

a higher level of service to high priority vehicles in the transportation network. 

A TMC should be involved in the early stages of planning for a managed lane facility, as this 

will ensure that TIM needs are taken into account during the design of a managed lane concept. 

The TMC will have knowledgeable staff that can provide valuable input into the design process, 

including the design and maintenance needs for ITS components, managed lane control software 

needs, the overall systems engineering process, and the physical designs of the managed lane, 

such as the location of access points and the type of separation treatments used. The TMC can 

also provide valuable input into the operational planning for the managed lane, including integration of the managed lanes with established ITS strategic plans and ITS regional architectures. 

The TMC plays a key role in development of operation plans, maintenance plans, and the TIM 

programs and performance measures that will be used on a managed lane facility. 

TMC Role in the Managed Lane Environment—Real Time TIM Response Activities 

and Support

While multiple transportation agencies may be responsible for operation of the corridor on which 

the managed lane operates, the TMC must treat the network as a single transportation system 
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EXECUTIVE SUMMARY

when coordinating during an incident. Interagency agreements and joint communications protocols ensure that the various agencies work efficiently to clear the incident and carefully monitor 

the effects. This includes the effect of any incidents in the general purpose lanes that may affect 

the operation of the managed lanes or require use of the managed lanes for the response. The 

ability of the TMC to coordinate among multiple agencies is key during incident detection 

and verification, as the TMC may detect an incident outside of its primary jurisdiction or may 

receive reports of an incident from another TMC, especially if multiple TMCs operate along 

one corridor. 

The response to an incident in a managed lane may be complicated by the physical access to the 

lanes. It may be worthwhile to have dedicated response vehicles, such as tow-trucks, pre-positioned at key locations along the managed lanes if recovery vehicles may not be able to easily 

access the lanes. Safety patrol vehicles on a patrol route provide a valuable source of incident 

detection and verification information. These vehicles can be dispatched by a TMC to the scene 

of an incident to assist with establishing a TIM zone, and can provide the TMC with accurate real 

time information which can be relayed to other agency partners. Quick and efficient response 

is important for minimizing facility downtime, maintaining access for priority vehicles, and 

reducing revenue losses on priced managed lanes.

A TMC may have the ability to support TIM by temporarily reducing demand on the managed 

lanes through the use of vehicle access management strategies. This could involve a vehicle 

eligibility change, which can be implemented by raising the vehicle occupancy threshold or 

eliminating access to the managed lane by vehicles paying a toll, in effect temporarily operating 

a HOT facility as an HOV facility. Priced managed lanes that have flexibility in setting prices 

can adjust toll rates to discourage vehicles from entering the lanes. In other cases, access to 

the managed lanes can be closed by activating Dynamic Message Sign (DMS) units, gates, or 

lane control signals. On managed lanes without access control features, the TMC can direct 

responders on the ground to block access to the lanes. 

The TMC will also support TIM in the managed lane by providing scene management support to 

responders, which is especially important when the managed lane has limited room to establish 

a typical TIM zone. ITS devices are used to notify travelers of the incident and actively monitor 

the scene. Coordination with partner agencies, maintenance of close communications with those 

agencies, and dispatching of additional resources needed to support an effective incident scene 

will take place in the TMC. Another function of the TMC is to provide traffic control support, 

which will supplement any vehicle access management strategies implemented. This includes 

typical traffic control functions of a TMC, coordination between agencies in the managed lane 

environment, monitoring and tweaking of the plan as needed, and coordinating the opening of 

movable barriers where required for the response. If diversions are needed, such as opening 

the managed lane to all traffic, the TMC will coordinate the implementation of the management strategy.

The final stage of the TIM process is the clearance and recovery phase. The TMC will provide 

significant support during the recovery and clearance process with the goal of restoring normal 

operation as quickly as possible to reduce the impacts to managed lane users. The support 
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provided will include coordination of necessary clearance and infrastructure repair resources. 

With the TMC’s coordination and resource planning abilities, the incident can be cleared as 

quickly as possible.

The TMC may have the ability to provide system and corridor management, as an incident may 

affect other parts of the transportation network well beyond the scene. TMCs may have the 

ability to implement some or all of these strategies. They include use of lane control signals, 

ramp metering, adjusting traffic signal timing, posting travel times, implementation of diversions 

including modal transfers, providing traveler information, and expanding motorist assistance 

patrols. These actions can be implemented through the coordination of multiple TMCs and 

agencies to have a true corridor effect of the TIM strategies implemented. 

Case Studies

Eight managed lane facilities in the United States were used as case studies for this guidebook:

1. Long Island Expressway (I-495) HOV Lanes (Long Island, NY).

2. I-35W Priced Dynamic Shoulder Lane (PDSL) System (Twin Cities, MN).

3. I-10 Katy Freeway Managed Lanes (Houston, TX).

4. I-95 Express Lanes (Miami, FL).

5. I-93 Contraflow HOV Lane (Boston, MA).

6. I-15 Express Lanes (San Diego, CA). 

7. I-85 Express Lanes (Atlanta, GA). 

8. I-495 Express Lanes (Fairfax County, VA).

The case study review revealed significant variation in the operation and physical design of these 

managed lane facilities, as well as the TMC role in TIM. A table containing a detailed comparison between the eight facilities can be found in Chapter 5 of this guidebook. Key findings are 

summarized as follows: 

• All managed lane facilities use the TMC to provide basic TIM functions found on typical non 

managed lane facilities. 

• All facilities have assigned police patrols for the managed lanes, with dedicated patrols 

solely responsible for the managed lanes in some cases and shared with the general purpose 

lanes in others. Special equipment may be needed to interact with toll equipment on priced 

managed lanes.

• When the managed lanes are operated by a different agency from the general purpose lanes, 

there are likely to be multiple TMCs with jurisdiction over a corridor. One TMC may have 

primary responsibility for general purpose lanes, and the other for managed lanes. In several 

cases, multiple agencies were co-located in one TMC.

• Three managed lane facilities adjust eligibility restrictions: I-85 in Atlanta, I-35W in the Twin 

Cities, and I-15 in San Diego. The restriction is implemented in HOT lanes by removing 
5

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EXECUTIVE SUMMARY

eligibility for toll-paying vehicles to enter and retaining the existing HOV restriction, rather 

than altering the HOV restriction threshold. 

• All agencies without a physical barrier between the managed and general purpose lanes, in 

addition to California (using designated access points) specifically cited the ability to open 

managed lanes or shoulders to general traffic. 

Additional findings about the case studies are discussed in detail in Chapter 5. Furthermore, 

three of the eight managed lane facilities investigated for this guidebook are presented in greater 

depth as case studies in Chapter 5 of this guidebook; Minneapolis’s I-35W Priced Dynamic 

Shoulder Lane (PDSL), Houston’s Katy Freeway Managed Lanes, and Northern Virginia’s I-495 

Express Lanes. 

Conclusions

In order for managed lanes to function properly, the facility must operate reliably with minimal 

downtime. The TMC supports this by properly preparing for TIM activities that will occur on the 

managed lanes, and then by supporting the real-time TIM activities during an incident. 

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CHAPTER 1—INTRODUCTION AND BACKGROUND

CHAPTER 1—INTRODUCTION AND BACKGROUND

Managed lanes are becoming an increasingly popular strategy for addressing the problem of 

traffic congestion in major metropolitan areas, as these are lanes designed to optimize the movement of large numbers of people within a small amount of roadway space. In order to accomplish 

this goal, managed lanes must respond to both recurring changes in traffic patterns and non-recurring incidents. 

The purpose of this guidebook is to 

document traffic incident management (TIM) practices that can be 

implemented from a transportation 

management center (TMC) within the 

managed lane operating environment. 

It provides a framework for successful 

development and implementation of a 

TIM program for planners designing 

new managed lane facilities, as well as 

for transportation professionals with 

existing facilities looking to optimize 

the use of their TMC as part of their 

TIM program. 

For the purpose of discussion in this 

guidebook, the term TMC is used in a broad sense. Its connotation is not limited to “direct” operational activities such as traffic monitoring and management or incident detection and response. 

Neither is it limited to consideration of personnel involved in these “direct” operational activities 

such as TMC operators or shift supervisors. Rather, the term TMC in this guidebook is a broader 

term which relates to the fact that TMCs are often an element of a larger program that performs 

or supports other activities, including strategic and operational planning, system design, and 

coordination of operational stakeholders. 

The content of this guidebook is divided into six chapters as follows: 

• Chapter 1—Introduction and Background

Overview of the guidebook, description of the managed lane operating environment, and the 

importance of TIM in managed lanes.

• Chapter 2—Unique Aspects of TIM in Managed Lanes

Description of how TIM in managed lanes is different from typical freeway TIM and special 

TIM-related considerations. 

• Chapter 3—TMC Role in the Managed Lane Environment – Preparedness

Description of best practices for day-to-day operation of the TMC to prepare for incidents in 

managed lanes, classified by TIM element. 

Figure 1. Photo. Uncongested managed lanes 

adjacent to congested general purpose lanes.
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ROLES OF TRANSPORTATION MANAGEMENT CENTERS IN INCIDENT MANAGEMENT ON MANAGED LANES

CHAPTER 1—INTRODUCTION AND BACKGROUND

• Chapter 4—TMC Role in the Managed Lane Environment – Real Time TIM Response 

Activities and Support

Description of the TMC’s best practices for detection, response, and clearance of incidents in 

managed lanes.

• Chapter 5—Case Studies

A look at how the best practices are applied on managed lane facilities in the United 

States. Practices on eight managed lane facilities are compared, and three case studies from 

Minnesota, Texas, and Virginia are analyzed in greater depth.

• Chapter 6—Conclusions

A summary of the most important findings presented in this guidebook. 

1.1 DEFINITION OF MANAGED LANES

There are several different definitions of managed lanes used by different sectors of the transportation community. While managed lanes can cover a broad range of facilities, the definition of 

managed lanes used in this guidebook is narrower. 

Figure 2. Photo. Managed lanes function as a 

“freeway within a freeway”. 

The Federal Highway Administration’s (FHWA’s) definition of managed lanes is: “Highway 

facilities or a set of lanes where operational strategies are proactively implemented and managed 

in response to changing conditions.” This definition is very broad and encompasses a wide 
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variety of facility types, ranging from dynamically priced express toll lanes to simple curbside 

urban transit lanes. 

This guidebook focuses on freeway managed lanes with actively managed operations, eligibility 

restrictions, and access restrictions that co-exist adjacent to non-managed general purpose lanes. 

From an operational perspective, these lanes operate as a “freeway within a freeway” with the 

managed lanes functioning separately from the general purpose lanes. 

Some facilities are considered managed lanes based on the FHWA definition, but are not a 

freeway within a freeway. Such facilities include stand-alone dynamically priced toll roads where 

all lanes are tolled, exclusive busways, and managed lanes on non-freeways. These facilities are 

not covered in this guidebook as TIM practices for these roadways are very similar to TIM on a 

normal freeway or urban arterial roadway. 

1.2 ACCESS TO MANAGED LANES

The success of a managed lane facility depends upon the ability to maximize the use of available capacity while regulating vehicular demand to prevent the lane from becoming saturated. 

There are various methods that can be implemented to regulate demand by controlling access to 

managed lanes. These methods can be used to manage traffic during an incident. Descriptions 

of the most common access control methods as they operate under normal circumstances are 

discussed below.

High Occupancy Vehicle (HOV) Lanes

A managed lane facility with a vehicle eligibility restriction 

that reserves the managed lane(s) for the exclusive use of 

vehicles with a driver and one or more passengers, including 

carpools, vanpools, and transit vehicles. HOV lanes may 

operate at all times, or only during peak hours with the lane 

open to general traffic during other time periods. Some vehicles are exempt from HOV access restrictions depending on 

the jurisdiction’s laws, such as electric vehicles, hybrid vehicles, transit buses and taxis 

with no passengers, and 

emergency vehicles. 

Page 256 

Figure 2G-1. Prefer

R3-13 

R3-14b 

Figure 3. Illustration. 

MUTCD sign showing 

HOV lanes have a 

minimum vehicle 

occupancy requirement. 

Express Toll Lanes (ETLs)

Managed lanes that charge a toll for access to the lane. Many 

ETLs utilize congestion pricing, where tolls increase as traffic 

volumes, traffic densities, or congestion increase. The theory is 

that a higher price will reduce demand and thus reduce congestion by “pricing out” vehicles whose drivers do not wish to 

pay the higher fee for access. ETLs may have rates that adjust 

Page 280 2009 Edition

Figure 2G-17. Regulatory Signs for Managed Lanes

R3-40 R3-42 R3-42a R3-42b R3-42c

R3-48 R3-48a

Figure 4. Illustration. 

MUTCD sign showing ETLs 

with congestion pricing have 

variable tolls. 
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CHAPTER 1—INTRODUCTION AND BACKGROUND

on a set schedule, or the rates may adjust dynamically 

depending on the traffic conditions in the lanes. ETLs 

use electronic toll collection in order to collect tolls with 

minimal disruption to traffic flow, and thus many require 

enrollment in an electronic toll collection program in 

order to use the lanes. 

High Occupancy/Toll (HOT) Lanes

HOT lanes are a hybrid between HOV lanes and ETLs. 

An occupancy requirement is set, and vehicles meeting 

the occupancy requirement can travel in the managed 

lane for free, while vehicles not meeting the occupancy 

requirement must pay a toll to travel in the lane. The toll 

structure typically utilizes congestion pricing to manage 

congestion in the lanes. Some HOT lanes require all 

vehicles to enroll in an electronic toll collection program 

and to carry a transponder, while other HOT lanes allow 

free use by HOVs with no transponder or toll account. 

Page 280 2009 Edition

Figure 2G-17. Regulatory Signs for Managed Lanes

Notes:

1. The ETC pictograph shown is an example only. The pictograph for the toll facility's adopted ETC 

system shall be used.

2. Changeable message sign elements shall be used for the numerals displayed for the variable tolls.

R3-40 R3-42 R3-42a R3-42b R3-42c

R3-45 R3-45a

Example of regulatory sign with

changeable message elements

R3-43 R3-44 R3-44a

R3-48

R3-48a

Sect. 2G.18 December 2009

Figure 5. Illustration. MUTCD 

sign showing HOT lanes are ETLs 

where HOVs do not pay for access. 

Bus Lanes

Bus lanes have a vehicle eligibility restriction permitting use only by buses. The restriction may 

allow any bus to use the facility, or it may restrict use to transit buses only. Bus lanes prioritize 

mass transit vehicle movement and are less prone to congestion than other types of lanes which 

allow cars to enter. In some cases, authorized transit buses are permitted to utilize the roadway 

shoulder to bypass traffic congestion. This is a type of bus lane that has fewer capital costs to 

implement, but requires additional training for bus drivers to use the shoulder while maintaining 

a safe operating environment for the buses, general traffic, and disabled vehicles parked on 

the shoulder. 

The access control methods discussed above represent most common strategies for controlling 

access to a managed lane. The details of how the strategies are implemented can vary widely 

among different facilities. The type of access control and the level of flexibility in adjusting the 

access requirements can potentially play a big role in TIM in the managed lanes. 

1.3 PHYSICAL DESIGN OF MANAGED LANES

Managed lanes are located next to general purpose lanes and there are varying degrees of 

physical separation between the two. The level of separation plays an important role in how 

authorities respond to incidents. The following is a brief overview of typical physical designs of 

managed lane facilities. 
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Shoulder

The right or left shoulder of the roadway is used as 

a full-time or part-time managed lane, and use of the 

shoulder is typically regulated by electronic signs. When 

the managed lane is in operation, there is reduced or 

no shoulder space on the side of the roadway with the 

managed lane. When the managed lane is not in operation, the shoulder can be used for emergency stopping 

or incident clearance. In some cases, shoulder use is 

restricted to authorized transit buses. There are fewer 

electronic signs, as there is a driver training component 

for all drivers utilizing the lanes.

Painted Buffer

The managed lane is separated from the general purpose 

lanes with a double white line or a wider painted “buffer 

area” that is illegal to cross. The painted buffer can be as 

narrow as 4 feet or wide enough for a disabled vehicle to 

fit between the lanes. Entering and exiting the managed 

lane is accomplished using gaps in the painted buffer 

where vehicles are allowed to change lanes. Alternatively, 

painted “slip lanes” that function as an acceleration/deceleration lane between the managed and general purpose 

lanes can be used. Painted buffers allow easy access to the 

managed lane during incidents, but rely heavily on voluntary compliance with buffer crossing prohibitions during 

normal operations. 

Continuous Access Lane

The managed lane operates as a typical freeway lane with 

some form of usage restriction. Drivers may enter and 

exit the lane at any location. This physical design allows 

easy access for incident response. For part-time managed 

lane facilities, the lane can either be closed or operated as 

an additional general purpose lane outside the typical operating hours.

Painted Buffer with Electronic “Invisible” Barrier

This design is the same as the painted buffer, with the addition of an electronic system to deter drivers from illegally 

crossing the buffer. This system uses a series of cameras, 

license plate readers, and/or toll transponder readers to detect 

Figure 6. Photo. Part-time 

shoulder lane. 

Source: FHWA

Figure 7. Photo. Managed lane 

separated from general purpose 

lanes with painted buffer. 

Source: FHWA

Figure 8. Photo. The left lane is 

a continuous access HOV lane. 

Source: FHWA

Figure 9. Photo. Invisible 

electronic barrier using toll 

tag readers and cameras. 
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CHAPTER 1—INTRODUCTION AND BACKGROUND

when a car enters or exits the managed lane between legal entry/exit points. A warning or violation notice is sent to drivers who do not follow the posted rules. This system provides a deterrent 

to illegal crossing of the buffer, and it can be easily deactivated if crossing the buffer is needed 

for incident response. 

Plastic Post Barrier

This design utilizes flexible plastic posts, sometimes referred to as “candlesticks”, placed inside a 

painted buffer area to separate the managed lanes 

and general purpose lanes. The posts can be located 

adjacent to the travel lanes, or there can be a paved 

shoulder between the posts and the travel lane. 

Plastic posts will not stop an errant vehicle from 

crashing through the barrier, but most drivers will 

typically avoid deliberately crossing the barrier. The 

posts can be removed if necessary to provide responder access to the managed lanes. The use 

of plastic posts may be impractical in northern climates due to the increased maintenance costs 

associated with damage caused by snow removal activities. However some agencies with priced 

managed lanes and lower rates of driver compliance with signs and markings may justify the 

increased maintenance costs if the plastic posts are used for revenue protection purposes. 

Figure 10. Photo. Plastic post barrier. 

Permanent Physical Barrier

A permanent physical barrier, such as a Jersey barrier, 

physically separates the managed and general purpose lanes. 

There is typically a full shoulder between the travel lane 

and the barrier. The managed lanes operate as a completely 

separate roadway from the general purpose lanes. This 

design prevents errant vehicles from crossing the barrier, 

but also restricts emergency access to defined access points 

along the facility. Figure 11. Photo. Permanent 

physical barrier creates two 

separate roadways. Zipper Barrier

A zipper barrier is a physical barrier that can be moved by 

a special mobile machine. Zipper barriers are often used 

to create “contraflow lanes”, where a lane in the off-peak 

direction of travel is used for travel in the peak direction. 

The zipper barrier has the advantage of physical separation between lanes, as it will stop most errant vehicles. 

The zipper barrier also has the advantage of flexibility in 

operations, since it can be moved to open or close lanes 

Figure 12. Photo. Zipper barrier as needed. Typically the barrier is moved according to 

and mobile machine.

Source: FHWA
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a set schedule usually around commuter peak periods; however it is also possible to move the 

barrier in the case of an incident. 

Reversible Roadway

These managed lanes are entire roadways that reverse direction, and are typically built to handle 

large directional peaks in traffic volumes. Reversible roadways are usually located between 

the two sets of general purpose lanes, but can also be elevated or located off to one side. The 

entry and exit points to a reversible roadway are carefully controlled with dynamic message 

signs (DMSs), signals, and gates to prevent wrong way entry into the lanes during normal 

operations. During incidents these features can be used to control access to the lanes or allow 

emergency access. 

1.4 IMPORTANCE OF TIM IN MANAGED LANES

TIM is the process of coordinating the resources of a number of different partner agencies and 

private sector companies to detect, respond to, and clear traffic incidents as quickly as possible in 

order to reduce the impacts of incidents on safety and congestion, while protecting the safety of 

on-scene responders and the traveling public. Efficient TIM is important because when an incident occurs, congestion quickly builds up and the likelihood of a secondary incident increases. 

Figure 13. Photo. An incident in a managed lane can inconvenience 

many people, such as transit riders, since vehicle occupancies are high.

The sooner an incident is detected, the sooner safety personnel can respond to it and clear it from 

the roads allowing traffic lanes to re-open and traffic to return to normal conditions. TIM assists 

with the process of creating a safe work area with proper signs and equipment for emergency 

crews responding to an incident. 
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CHAPTER 1—INTRODUCTION AND BACKGROUND

The effects of an incident and the importance of TIM are compounded in the managed lane 

environment for the following reasons:

• Priority access to managed lanes is given to vehicles with high occupancies or to drivers with

a high value placed on time, as evidenced by willingness to pay a toll for access. An incident

occurring in a managed lane will therefore adversely impact vehicles that require the highest

priority within the transportation network.

• Managed lanes are designed to move large numbers of people using limited roadway space.

Since the average vehicle occupancy in managed lanes is high, an incident in a managed lane

can impact a small number of vehicles yet impact a large number of people.

• Managed lanes provide eligible vehicles a more reliable trip and a higher level of service

compared to the general purpose lanes. The success of managed lanes depends on the reliability of the facility. Swift clearance of incidents will instill confidence in managed lane

users that the managed lane facility is reliable and that incidents will be cleared as soon as

possible. Lack of confidence in the reliability of a facility could cause users to abandon the

managed lanes, which in turn could increase congestion and decrease ridesharing.

A robust and effective TIM program will ensure that managed lane facilities operate as reliably 

as possible and that downtime is minimized. This in turn will provide an acceptable level of 

service to the greatest number of people and the vehicles with the highest priority within the 

transportation network, such as HOVs or transit vehicles. 

1.5 TMC OPERATIONS

The TMC is the most important TIM resource. The TMC is a centralized hub that provides realtime monitoring of the highway, incident detection and verification, coordination and support 

for incidents, and distribution of traveler information. The TMC helps to reduce congestion, 

increase safety, and increase the efficiency of the transportation network. These goals are typically achieved using the TMC’s communications capabilities and its access to ITS assets on the 

roadway network. 

Typical TMC TIM functions and capabilities include:

• Detection and verification of incidents.

• Notification and/or coordination with responders.

• Implementation of traffic management strategies to mitigate or manage traffic flow in the

area, such as revised traffic signal or ramp meter timing.

• Implementation of a traffic diversion (if appropriate).

• Distribution of traveler information related to incident status and conditions to the public

and media.

• Monitoring traffic conditions at and around an incident scene and adjust TMC response and

support actions as needed.

• Coordination with other TMCs and response agencies on incident status and conditions.
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• Supporting any needs for additional response, such as those needed for spill cleanup or

serious injuries.

• Supporting on-scene response with motorist assist patrols, traffic response teams, or 

emergency traffic control by motorist patrols.

• Logging incident related information, such as detection, response and clearance times.

• Standing down or revising traffic management strategies, support personnel, and traveler

information systems as the incident clears.

• Participation in post incident reviews at a later date.

Figure 14. Photo. Inside of the New Jersey 

Statewide Transportation Management Center.

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CHAPTER 2—UNIQUE ASPECTS OF TIM IN MANAGED LANES

CHAPTER 2—UNIQUE ASPECTS OF TIM IN MANAGED LANES

Many of these topics are familiar to transportation and emergency response professionals. This 

guidebook links these topics together. This chapter will examine how TIM using a TMC in 

managed lanes is different than typical freeway TIM, which is a critical component to understanding the best practices that will be presented later in the guidebook. 

2.1 NEED FOR INTERAGENCY COORDINATION

On most transportation corridors under the jurisdiction of a TMC, there is one transportation 

agency responsible for operation and maintenance of the entire corridor. However some managed 

lane facilities are operated by a different agency than the adjacent general purpose lanes. This 

will require coordination between the two agencies for normal operations and during incidents.

Figure 15. Photo. Express Lanes in Orange County, CA are operated 

by a different agency than the adjacent general purpose lanes.

Source: FHWA

The agency that ultimately operates a managed lane facility depends on many factors, including 

when the facility was constructed, if the facility was purpose-built or converted from another use, 

funding constraints, and the operating authority of the various transportation agencies in a metropolitan area. Typically, one of three types of agencies operate managed lanes:

• The same public sector transportation agency as the general purpose lanes: Typically a state 

DOT that operates freeways and other transportation facilities. The managed lanes will be 

well integrated into the transportation network and communication will exist between incident responders and only one transportation agency.

• A different public sector transportation agency than the general purpose lanes: Typically a 

toll road authority or operator, a transit agency, or a metropolitan planning organization. The 

operators of the general purpose and managed lanes may share a TMC or other transportation assets, and will generally have common goals of providing a seamless transportation 

network and providing premium service to carpools, rideshare vehicles or, drivers willing 
18

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to pay a congestion pricing toll. There is a need for interagency coordination between the 

two operators for TIM, maintenance, and operations, and this coordination will generally be 

more formal than when the same transportation agency operates both the general purpose and 

managed lanes.

• A private sector operator for the managed lanes alongside general purpose lanes operated by 

the public sector: Often a concession or other special operating agreement is made between a 

transportation agency and a private firm for designing, building, operating, and maintaining 

a managed lane facility. The private sector operator of the managed lanes may have different 

objectives than public sector transportation agencies, and each operator may have their own 

TMC, operating procedures, and ITS assets. Communication between the private sector 

operator of the managed lanes and the public sector transportation agency will typically be 

more formal and subject to specific protocols outlined in contract documents.

Having more than one transportation agency or operator responsible for roadways co-existing 

in a single right-of-way is unique to the managed lane environment. In some cases, the two 

operators’ jurisdictions are separated by only a few feet of pavement with a very simple barrier 

between the two, if any. The result of this physical configuration is a high likelihood of interaction between the general purpose lanes and the managed lanes during normal operations, 

maintenance, and incidents. Maintenance activities must be closely coordinated to ensure 

adequate operation of the transportation corridor and that two agencies are not competing for 

the same roadway space for their respective 

activities. An incident on one facility may 

be detected by the other facility’s operator. 

Additionally, an incident on one facility can 

quickly affect operation of the other facility. 

The barrier between the two facilities may be 

breached during the incident, and the barrier 

may need to be crossed by responders and 

diverted traffic.

All of the above scenarios will result in the 

need for close coordination between the 

operator of the general purpose lanes and 

the operator of the managed lanes if the two 

facilities are not operated by one agency.

2.2 ENHANCED 

TRAFFIC MANAGEMENT 

SYSTEM CAPABILITIES

Managed lanes usually have more ITS assets 

and TMC functionality than a typical freeway. 

Managed lanes are designed to allow proactive 

implementation of management strategies 

Figure 16. Photo. Managed lanes typically 

have extensive deployments of ITS 

equipment, such as these CCTV cameras.
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in response to changing traffic conditions. In order for this to occur, ITS assets must be able 

to detect when traffic conditions change to require a response from the operating agency. This 

will generally require a more robust deployment of ITS assets that can detect incidents than are 

found on a typical freeway. In some cases, the entire managed lane facility is within the range of 

a Closed Circuit Television (CCTV) camera. An agency in charge of operating a managed lane 

facility is generally willing to provide enhanced ITS and TMC functionality in order to ensure 

the success of the facility.

Examples of enhanced ITS assets and TMC functionality that can be found on many managed 

lane facilities include:

• Complete coverage of the managed lane system with CCTV cameras.

• Closely spaced detection equipment to gather volume, speed, and occupancy data.

• DMSs at regular intervals along the facility and at entry points.

• Dedicated enforcement and motorist assist patrols.

The enhanced capabilities of the TMC allow for better detection, verification, response, and 

clearance of incidents that occur along the corridor. This will result in incidents being cleared 

faster and subsequently less downtime for the managed lanes.

2.3 ENHANCED OPERATIONAL CONTROL

Some managed lane facilities have traffic control tools that can be activated from the TMC 

to support TIM. Managed lane facilities are more likely to have these capabilities than other 

freeway facilities.

Figure 17. Photo. Some managed lanes can be remotely 

closed from the TMC, such as this reversible facility.

Source: FHWA
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Some examples of control strategies that can be implemented from the TMC include:

Variable speed signing

Some managed lane facilities have changeable speed signs along the facility. These signs can 

be adjusted from the TMC to reduce the speed limit approaching an incident zone. Depending 

on the laws of the area where the managed lane is located, this variable speed may be advisory 

in nature or it may be an enforceable speed limit. In states where both an enforceable speed 

limit and an advisory speed are both permitted, the choice of which 

type should depend on the ability to effectively enforce the limit. An 

advisory speed may be more suitable for areas where police enforcement is not practical. The use of variable speed signing can encourage 

drivers to slow down when approaching a TIM zone, and thereby 

reduce the likelihood of injuries to responders, secondary crashes, 

and reduce the severity of any crashes that do occur in the incident 

management zone. An enforceable variable speed limit must be 

supported by state law, and driver compliance may vary depending on 

the level of enforcement normally associated with the managed lane 

facility. When an enforceable speed limit or advisory speed is used 

in combination with DMS messages warning drivers of an incident 

ahead, the reduced speed may be more effective as drivers will understand the need to slow down.

Figure 18. Illustration. 

MUTCD sign showing 

variable speed limits.

Lane control signals

These are the green arrow 

and red “X” signals that 

appear over lanes. Some 

managed lane facilities 

have lane control signals 

that can be used to 

remotely close and re-open 

lanes from the TMC. 

These signals can be used 

in the course of normal 

operations to open or close 

lanes, control entry to 

access points, and assist 

with switching direction 

of reversible facilities. 

Regardless of whether or 

not signals are used in the 

course of normal operations, available signals can 

be a handy traffic control 

Effectiveness of Lane Control Signals

Experience in some areas shows that the effectiveness 

of lane control signals is limited due to aggressive driver 

behavior and distracted drivers. While lane control signals 

can be used as a tool to manage traffic at an incident 

scene, the most effective way to establish an incident 

scene is with service patrol trucks and emergency vehicles. The greatest compliance with posted lane control 

signals occurs in free-flow, high-speed conditions.

In order to achieve increased rates of driver compliance 

with lane control signals, they must be deployed quickly 

and accurately, which requires a high level of attention 

from the TMC operator in addition to quick and accurate 

detection and verification of the incident’s location.
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tool during incidents. This will improve incident zone safety by directing vehicles out of the 

blocked lane prior to the incident, and can reduce backups by allowing traffic to merge when 

gaps are available rather than being forced to merge at the incident. Lane control signals will also 

allow lane closures to be implemented much faster than if the signals were not available.

Zipper Barrier

Managed lane facilities that have a zipper barrier can have the barrier moved to open or close 

lanes, allow for diversions, or allow emergency responders to reach an incident. The zipper 

barrier must generally be moved by a ground vehicle, and TMC staff can direct ground crews to 

move the barrier if needed.

Facility closure

Many managed lane facilities have some form of DMS units, signals, or gates at the entrances to 

managed lane facilities that could be used to completely close the managed lane facility to traffic 

from the TMC. This is a tool that can be implemented if a serious incident blocks all lanes, an 

incident is expected to be long in duration, or the impact to traffic will be high. Implementing a 

full closure of the managed lanes may be necessary to prevent severe traffic backups behind the 

incident or prevent vehicles from becoming “trapped” behind the incident. The closure can be 

implemented using signs dedicated to providing the open/closed status or by utilizing other signs 

normally used for other purposes, including the signs listing the toll rate for priced managed 

lanes. In such cases, the signs could be changed to display “closed” rather than a price. Although 

a facility closure may not prevent all vehicles from becoming trapped behind an incident, if 

some vehicles can be directed away from the incident scene, the response to the incident will 

be improved.

Diversions

A diversion can be implemented in one of two directions: general traffic can be diverted into the 

managed lanes, or managed lane traffic can be diverted into the general purpose lanes. A diversion is similar to a facility closure, though it is usually implemented by diverting vehicles already 

in the facility off of it at an intermediate location rather than simply preventing vehicles from 

entering at defined entry points. If traffic is diverted off at a defined exit point, DMSs can be used 

to the extent possible to guide vehicles onto the exit ramp. If a diversion is implemented at an 

intermediate point, responder assistance on the ground may be necessary to direct vehicles into 

the diversion and to remove any physical barriers that may exist. This effort can be supported by 

the TMC by activation of the DMSs to warn drivers of the diversion, closure of any entry points 

downstream from the diversion, and suspending automatic enforcement of regulations that are 

not applicable during a diversion, such as “invisible barriers”.

Adjusting toll rates

Priced managed lanes with dynamically adjustable toll rates can increase the price for use 

of the managed lanes in order to discourage all but the highest value trips from utilizing the 
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facility. The ability to adjust toll rates may be limited by the managed lane facility’s operating 

procedures. For example, some facilities have an upper limit on the tolls, and others adjust toll 

rates on a set schedule, and the ability to deviate from that may not be permitted. Other toll 

facilities adjust toll rates depending on traffic conditions to maintain certain minimum operating 

conditions, such as a 45 MPH travel speed. In some priced managed lanes, the algorithms which 

determine the toll price under normal circumstances can be overridden by TMC staff in the case 

of an incident to reduce the number of vehicles entering the managed lanes. This TIM tool may 

be useful where a full closure or diversion is not necessary, but a reduction in traffic volumes in 

the managed lanes is necessary to preserve the operating conditions in the lanes for high priority 

traffic such as transit vehicles. Careful consideration needs to be given to how drivers react to the 

toll rates displayed on the signs before relying on this as a TIM strategy. For example, on some 

facilities, increasing the toll rate may lead to an increase in vehicles entering the managed lanes, 

since drivers will mistakenly believe that a high price means traffic conditions are poor in the 

general purpose lanes. 

Adjusting vehicle eligibility requirements

This tool is similar to the adjustment of toll rates in that the goal is to reduce the demand on the 

facility. An existing vehicle occupancy requirement can be increased, an eligibility requirement 

could be implemented where none normally exists, or a HOT facility could suspend access for 

those paying tolls and restrict entry to HOVs only. This TIM strategy will typically be implemented by adjusting electronic signs at the entry points to the lanes, and could be constrained 

by state or local laws. For example, the operating agency may not have the authority to change 

the occupancy requirement from two person carpools to three person carpools, but may have the 

authority to deny access to single occupant toll-paying vehicles if the two person HOV definition is not changed, thus granting priority to HOVs. An alternative could be to restrict access to 

buses or other transit vehicles only, and disallow general traffic. The implementation of a vehicle 

eligibility requirement change will reduce demand on the HOV facility while preserving access 

for the highest priority vehicles carrying the most people.

Figure 19. Photo. Managed lanes can suspend all 

eligibility requirements and allow all traffic.
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Suspension of eligibility requirements

This TIM strategy will open the managed lanes to all traffic and is typically implemented in 

response to an incident in the general purpose lanes where the managed lanes are needed for 

diversion. Implementing a suspension of all eligibility requirements is generally not seen as 

a desirable TIM strategy, as priority access for eligible vehicles in the managed lanes is not 

maintained. However in some circumstances, there may be no suitable alternative to safely 

and effectively handle traffic from the general purpose lanes other than opening the managed 

lanes to all traffic. This TIM strategy can be implemented from the TMC by displaying detour 

information on electronic signs approaching the lanes, and suspending enforcement of tolls and 

occupancy requirements.

2.4 PHYSICAL ACCESS CONSTRAINTS

Managed lanes are more likely to operate in a physically constrained environment than a typical 

freeway segment. The physical layout of the managed lane facility will impact the TMC’s ability 

to perform TIM tasks during an incident, including allowing responder access to the managed 

lanes and the ability to implement a diversion. Section 1.3 of this guidebook discussed various 

physical layouts for managed lanes. The type of barrier and the lateral clearance between the 

travel lanes and barrier are factors in the amount of access constraint there is during an incident.

There are three levels of physical barriers which can separate a managed lane facility from the 

general purpose lanes: permanent physical barriers, movable physical barriers, or no physical 

barrier. Where a permanent physical barrier is used, access to and from the managed lanes 

can only be accomplished at designated locations, as crossing through the barrier will not be 

possible. Managed lanes may have fewer access points than the general purpose lanes due to 

their design. Many managed lane facilities with permanent physical barriers will have full or 

partial shoulders on at least one side, per typical design standards. This shoulder will allow for 

easier access to the incident scene and for vehicles to pass around an incident.

Movable physical barriers can take several forms, including zipper barriers, plastic “candlestick” posts, or removable sections of permanent physical barriers. With this design, the most 

desirable access to the managed lanes is through the normal entry and exit locations; however 

if access from these locations is not possible, the physical barriers can be breached or moved to 

allow access. A plastic post barrier can easily be breached by a large vehicle by driving over the 

posts. Alternatively, the plastic posts can be removed from their base or other barrier types can 

be moved to allow access. This activity must be accomplished by ground crews at the direction 

of the TMC. Since the removal of the barrier requires effort and a removed barrier must be 

replaced, this method of accessing a managed lane is not the preferred option for accessing an 

incident or allowing diversion. Managed lane facilities with removable barriers may not include 

shoulder space or a buffer area on either side of the lanes, as these managed lane facilities are 

often squeezed into available space within the right-of-way. This may limit the options for 

responders to access an incident scene more so than a typical freeway.
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Figure 20. Photo. Plastic “candlestick” posts can be 

moved to provide emergency access to the managed lanes.

If there is no physical barrier, accessing the managed lanes for TIM purposes is unrestricted, as 

vehicles can simply drive across the painted buffer. Physical access to managed lanes in these 

circumstances is no different than accessing an incident on a typical freeway. If there is electronic enforcement of the painted buffer, this enforcement can be suspended by the TMC during 

(or retroactively after) an incident.

2.5 FINANCIAL CONSIDERATIONS

Priced managed lane facilities involve the collection of tolls to manage demand on the facility. 

When an incident occurs on a priced managed lane, financial considerations will come into 

play. To a managed lane operator, maintaining the revenue stream from toll collections is an 

important objective.

When an incident occurs, a TMC may need to reduce vehicle demand on the managed lanes by 

eliminating the option to pay a toll for access and allowing access to HOVs only, or by raising 

the toll rate and having fewer vehicles paying for access. Raising the toll rate with fewer vehicles 

may have an adverse impact on revenue collections. In some cases, toll collection is completely 

suspended during an incident, such as when the managed lanes are used for general purpose lane 

traffic diversion.

Managed lane operators may be reluctant to take any TIM step that will reduce revenue collections. Careful consideration should be given to the available options in these circumstances, and 

the loss in revenue weighed against the level of service provided to drivers along the corridor. In 

some circumstances, it will make sense to maintain collection of tolls if capacity allows tollpaying vehicles to travel in the managed lanes without a severe degradation in service. However 

the managed lane operators will generally give priority to HOVs and transit vehicles in order 

to preserve the reliability of those modes of transportation. If there is not sufficient capacity to 

allow drivers to pay a toll for access to the managed lane facility, it may be logical to disallow 

those vehicles, even though it will cause a revenue loss, in order to preserve the level of service 

and reliability of the overall facility.
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When the managed lane operator and the general purpose lane operator are the same, the one 

agency will have the ability to decide on its own when to take steps that will reduce revenue. 

When the managed lane operator is a different public sector agency or private sector operator, 

specific guidelines governing the suspension of toll collection may be necessary in order to 

ensure that the need for revenue collection is properly balanced with the mobility needs of 

drivers along the corridor.

Figure 21. Photo. Suspension of tolls in managed lanes is rare 

due to concerns of revenue loss, but can be implemented during 

large incidents, such as this region-wide snow emergency.

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CHAPTER 3—TMC ROLE IN THE MANAGED LANE ENVIRONMENT—PREPAREDNESS

CHAPTER 3—TMC ROLE IN THE MANAGED LANE ENVIRONMENT—

PREPAREDNESS 

TMCs are designed to perform a variety of robust traffic and incident management activities. The 

extension of the TMC systems and activities to support TIM in the managed lane environment is 

a natural action which leverages these resources in a highly effective manner.

In some ways, the TMC role in TIM in managed lanes is the same as its TIM role on other 

highway facilities. Standard TMC systems and practices deployed for general transportation 

and incident management also apply to TIM in managed lanes. The benefit of this similarity in 

functions is that these TMC resources can be used for TIM in managed lanes with significantly 

reduced costs and effort.

However, as described elsewhere in the guidebook, the managed lane environment also presents a number of unique issues that require a TMC to address additional considerations. These 

include the potential need for a higher level of ITS device deployment, an increased need for 

enforcement, a greater number and type of partners to coordinate with, as well as different 

operational scenarios to plan and train for.

These systems and activities, whether standard for general traffic management or unique to 

managed lanes, involve technology, actions, or coordination that need to be planned, developed, 

and implemented in advance to enable the TMC to perform the required TIM activities when 

needed. Since these actions are done prior to and/or in preparation for TIM, they establish the 

TMC’s preparedness to perform during an incident.

Source: FHWA

Figure 22. Photo. Dispatchers working inside a TMC must make 

special preparations to handle incidents within managed lanes.
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This chapter focuses on the major elements that contribute to TMC preparedness to perform 

TIM tasks for managed lanes. The discussion of the various elements includes examples of 

state-of-the-practice and/or best practices that have been identified from a literature search and 

investigation of various managed lane facilities.

3.1 TECHNOLOGY AND COMMUNICATIONS

There is a nexus of technology and communication within a TMC, and the TMC has access to a 

wide variety of technologies that can support TIM on managed lanes. These include typical ITS 

devices such as CCTV cameras, Dynamic Message Signs (DMS), and the 511 traveler information hotline, as well as more sophisticated systems such as Computer-Aided Dispatch (CAD) and 

emergency communications. These technologies are often available to be leveraged for use by 

multiple response agencies in the managed lane environment at little or no additional cost.

Figure 23. Photo. A TMC will have many technology and communications resources, 

such as the ability to display travel times captured from roadway detectors on a DMS.

TMCs typically have established systems and/or protocols for effective communications with 

responders during incidents. This may involve simple methods such as contact information lists 

for other agencies, or more complex methods such as dedicated systems that allow for inter-operable communications between agencies. In addition, TMCs often have established protocols 

Communication Network Reliability

A TMC must have a reliable and dependable communication system in order to reliably 

carry out its functions. The communication systems employed by the TMC should 

include redundancy, self-correction and routing of communication paths, and dedicated 

repair crews to minimize downtime. In addition, the electricity costs for the communications equipment must be factored into the operating agency’s budget. 
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related to incident communications, dealing with both communications among responders and 

agency offices in addition to desired approaches for involving the media that support TIM.

The ITS utilized at TMCs incorporate both current and evolving communication technologies 

with the purpose of minimizing delays and improving traffic conditions for motorists. Typically, 

private sector contractors are responsible for installing and managing the operation of ITS 

components into the roadway and at the TMC. Example ITS systems include:

• Lane control signs.

• Ramp meters.

• CCTV cameras.

• DMS.

• Road Weather Information Systems (RWIS).

• Reversible Lane Systems.

• Detectors.

• Sensors.

During TIM, TMCs typically utilize technology and communications for the following actions:

• Displaying travel times and conditions using DMS (or broadcasting via 511 and media).

• Reducing or eliminating tolls when there is an incident.

• Converting managed lanes into a regular travel lane.

• Adjusting posted speed limits.

Most TMCs use commonly available technologies and strategies to monitor and operate 

managed lanes. However, there is a movement toward the use of more sophisticated technology 

and management techniques under a program called Active Traffic Management (ATM). ATM 

uses integrated speed harmonization, queue warning, ramp metering, lane control, and signal 

timing to manage traffic flow in the managed and general purpose lanes, as well as along parallel 

diversion routes, as an integrated corridor.

A substantial amount of data dissemination is involved with TMCs, both in terms of inputting and outputting to the ITS devices. TMCs have the communications infrastructure and 

computer systems to gather and analyze this data to adjust management strategies and produce 

performance data. Performance data is particularly critical to managed lanes because of their 

heightened need to keep operations at a high level of efficiency. Data are considered a very valuable resource, so robust data sharing agreements should be established among all stakeholders. 

As part of these agreements, technology and communication protocols should be included that 

facilitate information sharing. Specific examples include:

I-15 Express Lanes (San Diego, CA)

The California Highway Patrol provides enforcement services and is co-located with CalTrans at 

the TMC, which allows for direct coordination and communication during incidents.
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I-495 Express Lanes (Fairfax County, VA)

Formal protocols and operating procedures are in place to facilitate communication between the 

private operators of the managed lanes and the Virginia Department of Transportation.

New Jersey Turnpike (Statewide, NJ)

At the Statewide Transportation Management Center in New Jersey, the New Jersey Turnpike 

Authority, New Jersey State Police, and the New Jersey DOT are co-located in the same TMC 

facility, which promotes much needed coordination and communication between the agencies 

during incidents.

3.2 INTERAGENCY RELATIONS AND COORDINATION

TIM is a coordinated process that involves a number of public and private sector partners. 

Effective TIM requires comprehensive planning that involves all potentially affected stakeholders, including federal, state, and local agencies, as well as private sector, volunteer, and 

contract agencies. Since TIM involves such a variety of stakeholders, there is a need for strong 

interagency communications, especially in cases where managed lanes and general purpose 

lanes have different operators. From the perspective of motorists, there is only one transportation 

system, so the interagency interaction that takes place within the TMC facilitates the cohesiveness of the transportation network during an incident by bringing stakeholders together.

Interagency agreements established by the TMC will facilitate this coordination, and creating 

operational protocols ensures that the coordination to resolve an incident occurs in a predictable 

and orderly fashion. As part of the interagency agreements, a designated point of contact at each 

agency for planning-related matters should be identified, and a communication protocol with 

multiple points of contact at each agency should be established for real-time operational matters. 

TIM committees are often formed to establish these operational protocols, perform training 

exercises, and establish good interagency contact that can be maintained. For example, in New 

York and New Jersey, TIM steering committees have been created that consist of stakeholders 

from various member agencies who represent incident responders and private entities that have 

a vested interest in TIM. The purpose of these committees is to oversee the advancement of their 

respective TIM programs and to allow the agency representatives to become well acquainted 

with each other’s personnel and policies.

Since incident response involves a variety of organizations, each one should know their specific 

roles and responsibilities at an incident scene, especially in a managed lane environment. The 

following roles and responsibilities are common to all stakeholders during an incident:

• Ensure incidents are cleared safely, quickly, and efficiently minimizing traffic backups.

• Communicate with other responders.

• Create a safe working environment for responders.

• Follow established protocols.

• Follow agreed upon multidisciplinary procedures.
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• Build partnerships to support multidisciplinary, on-scene response.

Table 1 provides a list of TIM partners and some sample incident roles and responsibilities.

Table 1. TIM partners, agency roles and responsibilities.

Stakeholders Responsibilities

Law Enforcement

State Police, Highway Patrol, 

County Police, Sheriffs, 

Municipal Police

Assist in incident detection/verification

Secure the incident scene

Perform first responder duties

Assist responders in accessing the incident scene

Establish emergency access routes

Supervise scene clearance 

Direct traffic

Control arrival and departure of incident responders

Fire and Rescue

County and municipal fire 

departments, including 

volunteer services

Protect the incident scene 

Rescue/extricate victims

Suppress/extinguish fires

Emergency Medical 

Services (EMS)

Triage, treatment, and 

transport of crash victims

Provide medical treatment to those injured at the incident scene

Transport victims for additional medical treatment

Coordinate evacuation with fire, police, and ambulance or airlift

Towing and Recovery

Private companies responsible 

for the safe and efficient 

removal of wrecked or 

disabled vehicles, and debris 

from the incident scene

Recover vehicles and cargo

Remove disabled or wrecked vehicles and debris from the incident scene

Assist with vehicle stabilization and extrication, when requested

Remove debris from the roadway

Transportation Agencies

Develop, implement, and 

operate TMCs as well as 

manage Safety Service Patrols

Assist in incident detection and verification

Monitor traffic operations

Provide Safety Service Patrols

Provide traveler information to the public and media

Implement traffic control strategies and provide supporting resources 

Coordinate with law enforcement the establishment of alternate routes 

and assist in their operation 

Coordinate use of transportation agency resources (people, equipment, 

and materials) for clearance and recovery of incidents

When it comes to TIM in a managed lane environment, a single agency such as a state DOT 

may be responsible. In other cases, individual functions may be performed by separate agencies, 

private companies, or partnerships among them.

TMCs are valuable assets and serve as the point of contact for coordination and communication 

with responders and provide a means for dissemination of information to the public and media on 
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current traffic conditions and any restrictions there may be. TMCs perform four general functions: coordination, information dissemination, incident management, and roadway management.

Coordination with Internal and External Partners

Coordinate activities with internal groups and external operational partners. This coordination 

includes the managed lane operator and the operating agency for the general purpose lanes.

Information Dissemination

• Collect and provide information regarding the status of traffic and roadway conditions as

well as TIM activities.

Incident Management

Use ITS and additional resources to effectively manage the incident and other affected roadways 

as a cohesive transportation system.

• Dispatch appropriate response agencies.

• Assist response agencies in relaying communications to other agencies.

• Provide responders with information on other ongoing incidents.

• Provide data on agency responses.

Roadway Management

Use resources to effectively manage the affected managed lane corridor, the adjacent general 

purpose lanes, and parallel arterials during incidents.

Privately Operated Managed Lanes

When the agency operating managed lanes is a private firm, some unique factors must be considered. A private firm has a strong financial incentive to resolve incidents as quickly as possible 

in order to minimize facility downtime. Therefore a private operator may be willing to utilize a 

significant amount of resources in order to maintain reliability, minimize revenue loss, and focus 

on providing high quality transportation. However a private managed lane operator may not have 

the same long-established relationships with incident responders as public sector agencies.

A private sector managed lane operator will generally negotiate the terms of interagency coordination and shared responsibilities during an incident with adjoining public sector transportation 

agencies and incident responders in advance. In this way, each party will have expectations 

set and mutual understanding of responsibilities and obligations. This negotiation process will 

typically occur prior to the opening of the managed lanes, and may involve closed door sessions 

to protect the proprietary information of the private operator.

Protecting proprietary information is an interest of private sector agencies. Some information 

may only be released by the private sector on a need-to-know basis, whereas similar information 

would be available through an information request to a public sector agency. The negotiation 
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process should ensure that public response agencies have access to information needed to 

quickly and effectively perform TIM functions, and that all agencies will protect the confidentiality of the information.

3.3 MANAGED LANE ENFORCEMENT PATROLS

Enforcement patrols are essential to the operation of managed lanes because they enforce occupancy requirements and toll collections for priced managed lanes as well as provide response 

to incidents occurring along the managed lane facility. These activities are generally performed 

by law enforcement personnel such as the state highway patrol, local law enforcement agencies, and/or police associated with a toll or turnpike authority. The final decision on the agency 

responsible for enforcement varies from region to region and may be determined by state law 

and/or institutional agreements. Law enforcement should be engaged in the early stages of 

the planning process for managed lanes. This will ensure that their needs and limitations can 

be accounted for early in the process, including the development of plans for real-time incident response.

Key enforcement objectives on priced managed lanes should be designed to ensure that motorists 

comply with occupancy, toll payment, and access/egress policies. This is the primary reason 

why entities involved in the operation of managed lanes should coordinate with local agencies 

to agree on effective enforcement strategies. During incidents, the enforcement personnel are 

typically the first responders to the incident scene. Having adequate enforcement and driver 

compliance with laws will help prevent incidents from occurring in the first place, and having 

dedicated enforcement resources will ensure that first responders are nearby when an incident occurs.

Due to the differences in the physical designs of managed lanes, the necessary level of enforcement may vary. But without having proper enforcement strategies in place, the integrity of 

managed lanes, and especially priced facilities, will be compromised significantly during an 

incident. Managed lanes often have increased or dedicated police enforcement details and 

service patrols to support reliable operations. In some cases, dispatching of these resources 

occurs within one TMC. TMCs typically have contracts, Memorandums of Understanding 

(MOUs), or agreements related to the enforcement of managed lanes. The primary purpose of 

these agreements is for day-to-day enforcement of the managed lanes; however these agreements 

often involve dedicated enforcement patrols that would act as first responders to incidents along 

the managed lanes. Procedures that detail the frequency of designated enforcement patrols are 

included in these agreements and are based on discussions with local enforcement personnel 

who are familiar with the managed lane and understand the needs particularly during an incident. 

Some examples include:

I-495 HOV Lanes (Long Island, NY)

The INFORM TMC has a specific agreement with the county police departments that defines and 

funds their managed lane enforcement responsibilities.
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I-35W (Twin Cities Metropolitan Area, MN)

MNDOT contracts with the State Patrol to provide extra enforcement on the system during the 

HOT lane hours of operation.

Katy Freeway (Houston, TX)

The Harris County Toll Road Authority (HCTRA) funds dedicated enforcement patrols for the 

managed lanes using toll revenues.

SR 91 Express Lanes (Orange County, CA)

The California Highway Patrol is given the authority to divert general purpose traffic into the 

express lanes in the case of a severe incident. There are three enforcement zones along the 

express lanes that can be used during an incident.

Enforcement patrol staff can be a good resource for defining TIM requirements and providing 

ongoing coordination and support. In general, operators of managed lanes use toll revenues and 

enforcement fines to cover the costs of enforcement which may also support costs associated 

with TIM.

Source: New Jersey DOT 

Figure 24. Photo. Safety service patrol vehicle.
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3.4 TMC RESOURCES

TMCs have a variety of resources available to support their transportation management roles. 

In many cases they can support TIM in managed lanes using existing resources. In other 

cases, where the managed lane is tolled, some toll revenues may be available to support the 

TMC. Operators of managed lanes generally use toll costs and enforcement fines to cover the 

costs of enforcement. TMCs that monitor these priced managed lanes have an opportunity 

to have the TMC funded by these toll revenues and support enhanced incident management 

TMC operations.

TMCs often support their own agency’s efforts in recovery of funds that are used to replace 

infrastructure damaged in an incident. It may be possible to use these funding resources 

and procedures to support the same activity for managed lanes operated by other agencies. 

Examples include:

I-95 Express Lanes (Miami, FL)

Florida DOT funds the operation of the Express Lanes, the SunGuide TMC, and Road Ranger 

Service patrols through a combination of federal and state allocations supplemented by revenue 

generated by tolls.

I-495 HOV Lanes (Long Island, NY)

The NYS DOT provides directly or indirectly (contract) for the resources needed to operate and 

manage the HOV lanes, including INFORM TMC (the state TMC for Long Island) operations, 

ITS systems, HELP service patrols, enforcement, and HOV lane construction and maintenance. 

The majority of these services are funded by federal funds.

I-93 Contraflow HOV Lane (Boston, MA)

The Massachusetts DOT Highway Division provides the resources needed to operate and 

manage the contraflow lane including Highway Operations Center (HOC) operations, ITS 

systems, enforcement, and HOV lane construction and maintenance. The majority of these items 

are funded by federal funds.

3.5 TMC INVOLVEMENT IN MANAGED LANE DESIGN 

TMCs have the daily experience to understand the special operational needs of TIM in managed 

lanes. This knowledge can be brought to the table early in the process when managed lanes are 

being designed to ensure that the system will support the safest and most effective TIM during 

daily operations, as well as when the managed lane or managed lane systems need maintenance. 

TMC involvement is even more critically important in circumstances where the future operator 

of the managed lane may not have broad experience with TIM operations.

There are a number of key TIM operational considerations that the TMC can advise on during 

the design process.
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ITS Field System Design and Integration

The TMC should advise the designer of the managed lane on how to design the traffic 

management system to support TIM. Issues involved may include the technology used and the 

placement of devices such as detectors, CCTV, DMS, and lane control signals, as well as the 

compatibility and integration of such with any existing ATM systems. Provisions for shared 

control of devices should be addressed at this time.

ITS Field System Maintenance

During the design phase it is important to address the issue of future device maintenance in the 

context of relative factors such as placement of devices to allow maintenance without impacting 

the travel lanes and choice of system components and designs that increase reliability and minimize or simplify future field maintenance tasks.

Managed Lane Control Software

Control software would typically address core functions critical to managed lanes operations 

such as pricing algorithms, control of access devices, and toll tag reading. The TMC should 

address items critical to operations during incidents such as DMS and CCTV camera control 

as well as incident detection algorithms and logging capabilities. The system should facilitate 

communications with responders as well as distribution of traveler information at both the local 

and corridor level.

Figure 25. Photo. Enforcement area provides enforcement 

and service patrol vehicles a safe refuge from traffic.

Access and Separation Treatments

Managed lane access and separation treatments, or the physical design of the facility, have a 

significant impact on TIM. The decision on which of these type treatments will be implemented 

is often driven by factors such as right-of-way and transportation system connections. However, 
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the TMC should weigh in on the pros and cons of these options and, once an option is decided, 

provide input on how to design the approach to best facilitate TIM. For example, if a barrier 

separated system is selected, the TMC should advise that wide shoulders or enforcement areas 

need to be available for incident management scenes at specified intervals. In addition, access 

and egress points in the barrier should be provided to facilitate incident response as well as 

traffic diversions.

Systems Engineering Process

TMC personnel can often bring extensive knowledge of ITS Systems Engineering (SE) to 

the managed lane design process. In particular, including SE process elements such as the 

Concept of Operations, Systems Requirements, System Design, ITS Standards, Configuration 

Management and System Testing in the managed lane design will be an opportunity for the 

TMC to firmly set the stage for effective and compatible TIM systems and operations once the 

managed lane is implemented. The value that the SE process brings to effective TIM operations 

is discussed further in Section 3.6 TMC Involvement in Operational Planning.

The SAFETEA-LU Transportation Act of 2005 required that MPOs incorporate “operational and management strategies to improve the performance of existing transportation 

facilities” in their metropolitan transportation plans.

The following are examples of systems that incorporated effective TIM-related operational 

considerations in the design of managed lanes:

I-495 HOV Lanes (Long Island, NY)

The HOV lane is separated from the general purpose lane by a 4-foot painted buffer. The 

initial segments were designed with wide 10 to 14 foot shoulders on the left to accommodate 

enforcement and breakdowns. Segments constructed later had limited right-of-way so they were 

designed such that pavement markings create occasional pullout areas on the left side for these 

purposes. In addition, the center concrete median barrier was designed with occasional “slip 

ramp” type openings to provide enforcement with safe parking and access points.

Katy Freeway (Houston, TX)

This facility was designed with plastic “candlestick” post barriers separating the general purpose 

and managed lanes. The posts can be easily removed, or even driven over, when needed to facilitate access to incident locations as well as diversions to and from the managed lanes. In addition, 

the system design included 12 foot shoulders on each side of the posts to facilitate enforcement 

and incident management activities.
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I-35W (Twin Cities Metropolitan Area, MN)

This managed lane was designed with an ATM system covering the entire system. The ATM 

includes intelligent lane control signs at half-mile spacing that provide the means to open and 

close lanes or implement reduced speed advisories to support incident management activities.

Procurement Options

Managed lane projects such as express lanes may have increased financing and 

operational participation by the private sector. This may trigger consideration of 

alternate project procurement processes such as Design-Build-Operate-Maintain and 

Design-Build-Finance- Operate-Maintain. 

3.6 TMC INVOLVEMENT IN OPERATIONAL PLANNING

TMC personnel are often the agency’s lead for planning related to TIM programs. As such they 

are a key resource with respect to the manner in which TIM will be planned for and applied to 

managed lanes. TMCs should perform or support the incorporation of the managed lane TIM 

into their operational planning documents, processes, and activities and ensure that deployment 

is consistent with those plans.

There are a number of ITS and operational planning processes that are typically developed to 

direct and coordinate ITS deployment in an area. These planning processes and the key relationships for managed lane TIM include:

ITS Strategic Plans

Vision, goals and objectives for the managed lane TIM activities as well as deployment strategies, benefits and costs, funding plans and high level performance measures should be consistent 

with the local strategic plan.

ITS Regional Architectures (RA)

Managed lane TIM deployment should be consistent with the local RA. The RA should describe 

what TIM systems and services will be deployed and the information that is exchanged between 

them. The RA should also identify data and communications standards that apply.

Project Systems Engineer Processes

Systems that support managed lane TIM such as incident detection algorithms should be 

developed using the SE process described in Section 3.5.
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Operations and Maintenance Plans

Operations and Maintenance Plans should be developed for, or include, the appropriate managed 

lane TIM systems and activities including what systems are being deployed, the system functions, how they will be operated and maintained and who will do it.

TIM Programs

Managed lane TIM personnel and activities should be incorporated into the local TIM programs. 

The program should include involvement of local incident management stakeholders and be a 

resource for establishing and coordinating a variety of TIM activities including:

• Consistent and effective TIM response policies and practices.

• TIM goals, objectives and performance measures.

• Multidisciplinary TIM training.

• Deployment of effective and compatible technologies and communications.

• Special event planning and post incident debriefings.

Performance Measures Plans and Systems

The success of managed lanes, especially priced managed lanes, is highly dependent on 

monitoring and managing operations to maintain a high level of performance and reliability. 

Accordingly, establishing a plan for the collection of data and the production of comprehensive 

performance measures is critical. TMCs and their systems are routinely set up to collect traffic 

data and produce performance measures. These systems can easily be applied to managed lanes 

and can be revised to support the unique needs of managed lanes such as the development and 

implementation of algorithms that set pricing during normal and incident conditions.

The following are examples of ways in which systems incorporated TIM into the planning for 

managed lanes:

I-15 Express Lanes (San Diego, CA)

This facility fully incorporated TIM issues into their ITS/Operational planning processes. The 

following are examples of the documents created:

• Concept of Operations for the I-15 Managed Lanes Toll System.

• I-15 Managed Lanes Operations and Traffic Incident Management Plans.

• I-15 Managed Lanes Value Pricing Project Planning Study - Traffic Operations Plan.

• Systems Requirements for the I-15 Managed Lanes Toll System.

I-495 HOV Lanes (Long Island, NY)

A task force was established early in the HOV lane design phase to engage various stakeholders, 

including law enforcement, local and state government, transit agencies, the business community, and AAA. TIM in the HOV lanes was one of the topics addressed by the task force.
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I-495 Express Lanes (Fairfax County, VA)

The private operator of the managed lanes and VDOT were actively involved with planning for 

TIM and ITS system integration to ensure that effective sharing of ITS resources could occur 

between the two entities with different TMCs.

I-35W (Twin Cities Metropolitan Area, MN)

MNDOT designed their managed lane system to include Active Traffic Management (ATM). 

In addition to lane control signals, extra cameras were added as a result of a request from TMC 

operators to cover “blind spots”. The ATM software was developed in-house as open source 

software, and had features added to make lane control signal deployment for incidents easier and 

more consistent. TMC staff also requested the addition of emergency pull-off areas in sections of 

the highway where the shoulder was removed.

3.7 TMC PREPAREDNESS CHECKLISTS

These checklists can be used by TMC planning staff and operators to identify preparedness 

actions that can be taken to support TIM in managed lanes. They will help in the understanding 

of which unique aspects of TMC preparedness are applicable to their managed lane facility. It 

can also be used by operators of managed lanes to identify gaps in their preparedness that could 

lead to improvements in operation if addressed.
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TMC Planning 

 Preparedness Checklist

Use and share technology and 

communications systems

Establish protocols related to 

incident communications

Develop data sharing agreements among 

agencies

Technology and 

Communications

ITS Field System Design and Integration

ITS Field System Maintenance

Managed Lane Control Software

Managed Lane Access and 

Separation Treatments

Design elements of Project Systems 

Engineering Documents and Processes

TIM Operational Considerations 

are Incorporated into the Design 

of Managed Lanes

ITS Strategic Plans

ITS Regional Architectures

Planning elements of Project Systems Engineering 

Documents and Processes

System Operations and Maintenance Plans

Local TIM programs

Data Collection, Fusion, Analysis and System 

Performance Measures 

TIM Operational Considerations are 

incorporated in Operational Planning Processes 

and Documents related to Managed Lanes

Create interagency agreements 

established by the TMC

Interagency Relations 

and Coordination 

Ensure enforcement levels and funding 

for such are adequate 

Define roles, responsibilities 

and protocols 

Managed Lane 

Enforcement Patrols 

Share TMC resources 

Confirm that sharing agreements are 

in place

Examine and obtain funding for 

managed lanes

TMC Resources

Figure 26. Checklist. TMC Planning Preparedness Checklist.
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TMC Preparedness— 

 Operator’s Checklist 

Know how to use various technology 

and communications systems in the TMC

Know what ITS resources are located on 

the managed lane system, where the 

devices are, and the design limitations of 

the devices

Understand policies and protocols for use 

of different communications tools and 

ITS devices 

Technology and 

Communications

TMC Resources

Understand protocols for the use of 

shared TMC resources

Design of Managed Lanes

Know location of access and egress 

points along managed lanes

Have protocols, maps, and response 

plans for each segment handy 

Contact information for all TIM 

responder agencies

Contact information for other 

transportation agencies/providers along 

managed lane corridor

Know TIM responsibilities/jurisdiction of 

each partner agency

Participate in interagency training 

exercises that are offered

Interagency Relations 

and Coordination 

Know which agency has primary 

enforcement jurisdiction

Remember that enforcement patrols 

are a critical source of TIM information 

and are typically the first responders on 

the scene

Understand the general level of motorist 

compliance with the managed lane 

operating rules – this may play a role in 

TIM strategies chosen during an incident 

Managed Lane 

Enforcement Patrols 

Figure 27. Checklist. TMC Preparedness—Operator’s Checklist.
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CHAPTER 4—TMC ROLE IN THE MANAGED LANE ENVIRONMENT—REAL TIME 

TIM RESPONSE ACTIVITIES AND SUPPORT

Traffic Incident Management (TIM) is one of the primary functions of a TMC. TMCs are 

equipped with a wide variety of systems that support the real time monitoring of the highway, 

detect incidents, coordinate/support response, and distribute traveler information. 

TMCs are usually operational at all times, or at least during hours that cover the most congested 

time periods. TMCs have operations personnel resources and the expertise to perform 

TIM functions.

The most effective use of the TMC’s resources is critical to ensure prompt detection, response, 

and clearance of an incident in the managed lanes. The focus of this chapter will be on TMC 

practices learned through the literature investigation that will minimize detection and response 

time, provide adequate travel information to users of the managed lanes, and effectively control 

vehicular access to the incident scene to allow for quick clearance of the incident and return to 

normal operations.

4.1 SHARED OPERATIONS RESPONSIBILITIES

TIM is formally defined by FHWA as, “the process of coordinating the resources of a number 

of different partner agencies and private sector companies to detect, respond to, and clear traffic 

incidents as quickly as possible to reduce the impacts of incidents on safety and congestion, 

while protecting the safety of on-scene responders and the traveling public.” In a managed lane 

environment where the managed lane is operated by a different entity than the general purpose 

lanes, this coordination is particularly important, especially in situations where there are multiple 

TMCs responsible for operation of the corridor. Strong partnerships and previously agreed upon 

Figure 28. Photo. Traffic incident and response.

Source: FHWA
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operating procedures should be developed among transportation and response agencies to ensure 

smooth operation of the managed lane facility. Priced managed lanes in particular require significant real-time traffic management, including monitoring traffic and responding to incidents.

Figure 29. Photo. The I-495 Express Lanes in Fairfax County, VA are 

privately operated while the general purpose lanes are operated by the 

state DOT, yet they must function as a unified transportation system.

TMCs often treat the transportation network as a single system and have extensive experience in 

coordinating operations with multiple operating partners. During different types of incidents, the 

specific details of sharing responsibilities will be critical to ensure that the incident is detected, 

verified, responded to, and resolved efficiently. TIM on a managed lane and especially a priced 

managed lane is important to maintain the reliable and quick trip that motorists expect from 

the facility. A variety of entities may be involved in this function including state DOTs, state 

highway patrol, local emergency response units, and private towing and recovery contractors. 

The degree of coordination challenges increase if the agencies are not co-located in a single 

TMC, or if one of the operators is a private sector entity. In these cases to coordinate TIM efforts 

between key stakeholders responsible for the corridor, formal interagency agreements and joint 

operations protocols should be implemented. These protocols should aim for quick response and 

incident clearance, and outline the individual responsibilities of each entity.

The following situations would require additional coordination among the different entities 

involved in operating a managed lane facility:

• Increased traffic volumes in the adjacent general purpose lanes and/or in the managed lanes.

• Nonrecurring incidents on the general purpose lanes, which will influence speeds and create

increased demand for the managed lanes.
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• Nonrecurring incidents, such as minor/major incidents on the managed lanes, which can slow

or shut down managed lane operations.

• Incidents of any kind on nearby roadways that may shift demand to the managed lanes or

adjacent general purpose lanes.

In the event of an incident on the general purpose lanes, responders might need to use the 

managed lanes to respond to the incident. If an incident occurs on the managed lane or the 

general purpose lane, traffic might need to be diverted to the adjacent lanes. If different agencies 

operate the general purpose and managed lanes, revenue considerations may complicate agency 

speed or desire to implement diversions, but sometimes it is absolutely necessary. For example 

the I-15 HOT Lanes in San Diego, CA have procedures in place where tolls can be remotely 

eliminated if an incident occurs within the express lanes. If an incident occurs on the general 

purpose lanes, CalTrans has the ability to open the express lanes to all traffic. Similarly, tolls are 

not collected when the express lanes are used by general traffic.

Where there are multiple TMCs responsible for operation of a corridor, personnel at both TMCs 

must work together to ensure that the corridor functions seamlessly as a single transportation 

system. If one TMC is responsible for the managed lanes and another TMC covers the general 

purpose lanes, each TMC should have procedures in place to establish quick communication 

with the other TMC in the event of an incident, as it is possible that an incident can be detected 

by the “wrong” TMC. The correct TMC can then take the lead on the incident response. 

In some cases, the managed lane operator may not have a fully equipped TMC, and may instead 

rely upon a regional TMC for assistance with TIM. In such cases, it is critical to have agreements 

in place covering various incident types and severities such that the TMC is ready to support 

the managed lane operator when an incident occurs. The TMC may not have direct operational 

control over the managed lanes, but it can still provide assistance with dissemination of traveler 

information, dispatching responder resources, and assisting with scene management. 

Specific examples of shared operations responsibility include:

I-10 Katy Freeway (Houston, TX)

Texas DOT operates the general purpose lanes and the Harris County Toll Road Authority 

(HCTRA) operates the managed lanes. HCTRA has its own TMC, and also has staff at Texas 

DOT’s TMC.

I-495 Express Lanes (Fairfax County, VA)

Virginia DOT performs the traffic operations for the general purpose lanes and Capital Beltway 

Express, which is a private entity, operates the managed lanes. The two TMCs are connected via 

a dedicated communication link for sharing information.
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I-85 Express Lanes (Atlanta, GA)

Georgia DOT operates the general purpose lanes and the State Road and Tollway Authority 

operates the managed lanes.

I-15 Express Lanes (San Diego, CA)

The tolling system is operated by SANDAG, the local MPO, and is supported by the CalTrans 

TMC. SANDAG relies upon the CalTrans TMC for operational support and TIM. CalTrans has 

the ability to override normal operation of the tolling system in the event of an incident.

Ideally, interagency agreements regarding TIM policies that include information sharing and 

incident response procedures should be in place and familiar to all entities involved in the 

operation of the managed lanes, such that all stakeholders are on the same page regarding which 

agency is responsible for what when an incident occurs.

4.2 TIM PROCESS

The stages of the typical TIM process involve the following as depicted in Figure 28:

• Detection.

• Verification.

• Response.

• Scene Management.

• Motorist Information.

• Clearance.

• Recovery.

The TIM process for incidents in managed lanes is the same as for incidents occurring in general 

purpose lanes and other areas. The process has been implemented and tweaked over many years; 

however each managed lane system has its own unique considerations due to each unique operating environment and these must be addressed in any customized TIM plan.
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Figure 30. Chart. Stages of the TIM process.

4.3 INCIDENT DETECTION AND VERIFICATION 

Detection and verification are the initial stages of TIM where vital information is gathered on an 

incident. Detection involves determining that an incident has occurred and notifying the agency 

or agencies that are responsible for maintaining the roadway. Detection methods can be grouped 

Figure 31. Photo. Verification of the exact location of the incident 

is important when there is physical separation between lanes.
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into the following three general categories: Public Input, ITS Components, and Responder 

Reports. Examples for each method include:

Public Input

• Cell phone calls from motorists.

• Motorist aid telephones and call boxes.

ITS Components

• CCTV cameras viewed by TMC operators.

• Electronic detection (video processing, radar, induction loops) with traffic incident 

detection algorithms.

Responder Reports

• Input from other transportation agencies/TMCs along the corridor.

• Law enforcement patrols.

• Monitoring responders’ dispatch audio.

• CAD feeds from responders.

• Service patrols.

• Aerial surveillance.

• Calls from DOT or public service crews.

• Traffic reporting services.

In urban areas where managed lanes are present, there are higher traffic volumes and robust cell 

phone coverage, which will lead to quicker detection of incidents. Ability to detect an incident 

faster helps to begin the TIM process to clear the incident as soon as possible.

After detection, verification is the key next step during TIM. Verification involves confirming 

that an incident has actually occurred, including determining the type of incident, determining 

its exact location, and gathering as much pertinent information needed to dispatch the proper 

response personnel and resources. Proper verification of an incident in a managed lane environment is very important, especially where there is physical separation between the managed 

lanes and general purpose lanes. An improper verification could lead to incident response being 

dispatched to the wrong side of the physical separation, which will lead to longer clearance 

times since resources must be repositioned. Verification can be performed onsite by emergency 

personnel or offsite by TMC personnel and generally include the following methods:

• CCTV images.

• Law enforcement at the scene.

• Communication from aerial surveillance sources.

• Combining information from multiple telephone calls.
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Since managed lanes may involve multiple agencies it is especially important that TMCs have 

the capability to gather information from different sources. The collective information received 

from these sources should be used by the TMC to ascertain the type and severity of an incident, 

identify which agency has primary jurisdiction, and relay this information to the appropriate 

responding agencies.

Effective incident detection and verification is especially important for managed lanes because:

• Users of managed lanes, especially those paying a toll, expect a high level of service.

• Responders to the incident may need special information to properly access the incident scene and alert them of any dangerous conditions which may exist such as fire or 

hazardous materials).

4.4 INCIDENT RESPONSE

Incident response is typically considered the most important component of the TIM process. 

Incident response involves dispatching the appropriate personnel/equipment and activating 

the appropriate communication links and motorist information to media that a traffic incident 

has occurred. In order to facilitate a timely and effective response it is important that TMCs 

coordinate with enforcement personnel and other incident responders on the dispatch of 

response to collect all necessary information. The following are a few sample questions that 

TMC staff should ask when corresponding with emergency personnel or other persons reporting 

an incident:

• What is the exact location of the incident (roadway, direction, reference marker)?

• Is the incident in the managed lanes or general purpose lanes?

• Has the barrier between the general purpose and managed lanes been breached?

• What type of incident?

• What is the number and types of vehicles involved (trucks, cars, buses)?

• What is condition of vehicles involved (upright or overturned)?

• What is the severity of the incident? Are there any injuries?

• Are there any lanes blocked (by vehicles or debris), and if so which lanes?

Disseminating the incident details collected is a significant role for the TMC because dispatching 

incorrect equipment and resources can have adverse effects on managing an incident, which can 

result in increased clearance times, or secondary incidents, or possibly even further injuries and 

fatalities. TMCs often have access to dedicated safety service patrols that are able to respond 

quickly and provide assistance at an incident scene.

Some agencies utilize “simultaneous dispatch”, whereby law enforcement and service patrol 

vehicles are dispatched while the verification step is occurring. After the information is verified, 

any updated information can be communicated to the responders via radio, CAD, or response 

agency dispatchers. 
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Source: New York State DOT 

Figure 32. Photo. These New York State DOT HELP trucks have onboard 

cameras linked to the TMC to provide realtime incident information.

The managed lane environment may present additional challenges to traditional incident 

response functions coordinated by a TMC, as there may be limited physical access to the 

managed lanes for responders, and the lanes may have reduced or restricted space for TIM zones, 

Figure 33. Photo. Pre-positioned service vehicles or service vehicles on a roving patrol 

can monitor the managed lanes and provide quick response if an incident occurs.
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which can complicate TIM response and the ability to establish a safe TIM zone. To overcome 

this challenge it may be beneficial to have prepositioned response and recovery vehicles at key 

locations along the managed lane, especially where recovery vehicles may have limited ability to 

enter a managed lane facility. As mentioned previously, TMCs coordinate with dedicated safety 

service patrols so it would be ideal to have these patrols monitor the managed lanes to quickly 

aid in a response when an incident occurs. For example, in the Hudson Valley region of New 

York there are dedicated Highway Emergency Local Patrol (HELP) vehicles that patrol designated routes and are equipped with a live video stream to the TMC. The dashboard cameras are 

used to automatically relay real time incident information to TMC personnel which allows them 

to visually see incident details that aid in expediting a response.

Another method used to coordinate response 

efforts is the development of TIM teams along 

the managed lanes dedicated to responding 

to incidents. The mission of TIM teams is an 

inter-agency coordination among all emergency responders to understand the need for 

quickly and safely responding and clearing 

incidents from the highway. TIM needs vary 

from state to state, so TIM teams have the 

ability to adjust to the needs of their jurisdiction. Urban areas that generally have a large 

amount of congestion and incidents may require a response from multiple agencies, whereas 

non-urban areas may require a response from only one or two agencies. Additionally a managed 

lane environment might fall under the jurisdiction of multiple agencies, so it is important to 

develop these TIM teams in advance to communicate regularly and coordinate response efforts.

Providing a timely and effective response reduces incident durations and ultimately the amount 

of time the roadway operates at a reduced capacity. This is especially important for priced 

managed lane systems where reduced capacity could affect the amount of revenue collected.

The US Fire Administration’s Traffic 

Incident Management Systems Report 

(FA-330, March, 2012) includes an 

extensive discussion of traffic incident 

management responder safety, scene 

management and traffic control.

4.5 SCENE MANAGEMENT AND TRAFFIC CONTROL

TMCs can be used effectively to support incident site management and traffic control in 

managed lanes, in many cases using unique assets that may be available in those lanes. TMCs 

support quick, safe and efficient response to the incident by coordinating with on scene response 

personnel to set up a safe traffic control strategy and safe incident scene. TMCs can use a variety 

of transportation management strategies to control the traffic that will use the facility to meet 

the objective of safe incident clearance. This reduces congestion, helps to create a safer incident 

management zone, and hastens incident clearance.
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Figure 34. Photo. Incident scene management using DMS messages.

Incident zone traffic control 

to create a safe work area.

The following describes these strategies and actions in more detail.

Scene Management

Scene management involves the establishment of a safe and effective area where responders can deal with the incident response 

and clearance. Ideally, if vehicles are drivable and there are no 

injuries, the vehicles can be moved to a shoulder, pull off area, 

or off the roadway. If the vehicles cannot be moved, then traffic 

can be routed around in the vicinity of the scene or, if necessary, 

diverted from the area. Managed lanes can introduce complexities 

with scene management when the shoulder area is limited and 

cannot accommodate the incident scene set up without impacting 

traffic flow, or where barriers may make it difficult or impossible 

to allow vehicles to exit or to divert traffic in the immediate 

vicinity of the scene. Scene management also involves elements 

such as proper parking of response vehicles and the use of high 

visibility apparel. Accordingly, it is primarily the function of the 

onsite responders. However, the TMC can support effective scene 

management in the followings ways:

• Notify travelers of the incident site and warn of conditions via traveler information systems 

such as DMS.

• Monitor the scene for conditions and assist as requested in the selection of an effective site.

• Maintain close communications with the responders regarding traffic conditions at and near 

the scene; discuss scene management changes needed, if any, as the incident evolves.

• Support the establishment of a safe and effective scene by dispatching motorist assist patrols 

or traffic response teams that can help plan, establish and protect the scene.

Figure 35. Illustration. 
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• Coordinate response from the appropriate entity where it is necessary to open access to the 

scene for responders’ access and egress.

Traffic Control

Implementing effective traffic control at and around the incident management scene can help 

increase the safety of the responders as well as reduce the potential for secondary vehicle 

incidents. It may involve either providing for the safe passage of vehicles around the scene or 

diverting traffic away from the scene entirely. 

The TMC can support effective traffic control for the incident in the following ways:

• Coordinate with responders to develop or explain the traffic control plan.

• Support the implementation of the traffic control plan by dispatching motorist assist patrols 

or traffic response teams that can deploy flaggers, cones, warning signs, portable DMS and 

other devices as needed at or near the scene.

• Coordinate response from the appropriate entity where it is necessary to open access to the 

facility for traffic diversion by actions such as the removal of cones or opening access/egress 

points in barriers.

• Where managed lanes have movable barriers, adjust the lane configuration to support the 

need for revised traffic flow.

• Where available, open special use lanes such as HOV or shoulder lanes to accommodate 

traffic flow around the incident scene.

Additional actions such as controlling vehicle access to the facility to reduce traffic volumes via 

revised managed lane pricing or eligibility or through access control at the access and egress to 

the managed lanes are discussed in the subsection on Vehicle Access Management. The ability 

for a TMC to implement pricing or eligibility changes may be limited by state and local laws.

The following are examples of effective TIM-related scene management and traffic control 

strategies for managed lanes:

I-15 Express Lanes (San Diego, CA)

Freeway service patrols support incident response and scene management on this facility. For 

major incidents, a traffic management team may be dispatched in a truck with a mounted DMS 

attached to the vehicle. That team will assist the incident response in a variety of ways such as 

providing back of queue warning and traveler information. The system uses a movable barrier 

to adjust the number of managed lanes in each direction. The movable barrier can be “broken” 

if needed to provide access at intermediate points in the system for traffic diversions. CalTrans 

operates the system and is empowered to adjust the lane configuration or suspend tolls if needed 

in response to a major incident.
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I-85 Express Lanes (Atlanta, GA)

Traffic diversion policies have been created that allow responders to divert traffic as needed 

between the express and general purpose lanes in the event of a major incident. This action is 

facilitated by the fact that the barrier separation is a painted buffer. The State Road and Tollway 

Authority operates the system and will waive any toll violations created by crossing this “invisible barrier” during these major incidents.

I-93 Contraflow HOV Lane (Boston, MA)

Two radio dispatched tow trucks are pre-positioned along the facility whenever the contraflow 

lane is open. These trucks can be quickly dispatched to the incident scene to support safe scene 

set up as well as incident clearance.

Source: FHWA

Figure 36. Photo. Some managed lanes can adjust vehicle 

occupancy thresholds or suspend access by tolled vehicles.

Vehicle Access Management

One of the unique aspects of some types of managed lanes is that the TMC may have the ability 

to alter vehicle access to the managed lanes in order to reduce congestion, create a safer incident 

management zone, and hasten incident clearance. This can be done by changing vehicle eligibility (raise occupancy requirements or eliminate access for toll paying vehicles into HOT lanes), 

pricing (raise the vehicle use price), or through access control (utilizing gates or signals). Many 

of these access changes can be made directly from the TMC. In some cases the TMC may have 

to use its communication infrastructure to coordinate with ground personnel to implement the 

changes and monitor the effects. This section discusses these unique access management techniques and how they can enhance TIM in managed lanes. 

It should be noted that the vehicle access management techniques described below are usually 

accomplished through information and control systems. These systems are implemented by the 

TMC responsible for operations of the managed lane. In cases where separate TMCs control the 

managed lanes and general purpose lanes, coordination between the two TMCs is required. In 

cases where a separate toll agency is involved, coordination with that agency may be required if 

revenues will be affected. In these cases it is important to work out system functional and control 
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issues and create operational agreements and protocols 

during the system design phase.

Vehicle Eligibility

The most common eligibility requirement associated with 

managed lanes is vehicle occupancy. Typically, HOT lanes 

allow free use of the managed lane based on a minimum 

number of vehicle occupants – usually two or three. In the 

event of an incident requiring reducing the traffic volumes 

in the managed lanes, it might be possible to temporarily 

raise an HOV 2 requirement to HOV 3 if local laws and 

policies allow this strategy. The TMC could implement this 

change using tools such as DMS and managed lane access 

signs at the points of entry. However, HOV occupancy 

enforcement requires manual techniques and it may be 

difficult to get full compliance. An alternative vehicle eligibility change could be to suspend access by single-occupant 

vehicles in a HOT lane and only allow HOVs. This can be 

implemented without adjusting the occupancy threshold, 

which may not be allowed based on the state’s laws. The 

managed lane could also be closed completely if necessary. 

Techniques for such situations are described in the below 

section Access Control.

Figure 37. Photo. Priced 

managed lanes can increase the 

toll price to reduce demand.

Pricing

Many managed lanes have a pricing element 

to them, such as HOT lanes and ETLs. Pricing 

allows vehicles not meeting eligibility requirements (such as HOV 2) to use the lane by paying 

a toll. The toll is usually variable, based upon 

factors such as time of day or congestion levels. 

Vehicles using the lane via pricing eligibility 

usually need to have a toll tag. Pricing technology allows the operating agency to meter 

traffic to optimize travel on the managed lane 

and also allows for a TMC to meter traffic 

flow in response to an incident. The price can 

be raised to very high levels to greatly reduce 

the toll-paying traffic. Priced managed lanes 

are equipped with systems for altering the 

toll charge, via DMS or signs at the managed 

lane access point of entry. There may also be 

Figure 38. Photo. Some managed lanes 

have signs and gates that can be used to 

quickly close the lanes during an incident.
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separate lanes for toll paying vehicles and those can be closed as described in the below section 

Access Control.

Access Control

There are a variety of ways in which physical access to managed lanes may be controlled. In all 

cases, TMCs would play a primary role either in direct operations or coordination of operations. 

Access control techniques that are largely technology-based include:

• Overhead DMS and lane/speed control signs at frequent intervals on the facility.

• Separate ramps or direct connections that have gates and/or closure signing systems.

• Separate access points in the highway with positive entrance control lanes and gantries.

In some cases, the design of the managed lane does not facilitate the use of technology-based 

access control systems. In these situations it is necessary to implement techniques that are more 

manual oriented such as:

• Reversible Lanes: the gates and signing may need to be moved and the lane configuration

may need to be reconfigured.

• Traditional HOV Lanes with Continuous Access: access control would need to be accomplished by techniques such as DMS and/or manual closure techniques such as placement of

police cars, cones or barriers at access points.

In any case, whether access control is technology-based or manual-based, it can be seen that the 

TMC will play a large role in adjusting access control to facilitate TIM in managed lanes.

The following are examples of effective TIM-related access management systems for 

managed lanes:

I-15 Express Lanes (San Diego, CA)

This is a HOT lane type system with 

reversible lanes which is implemented and 

operated using a moveable barrier. Moveable 

barriers can create additional complexities 

in restricting access due to issues associated 

with reversing traffic and wrong way movements. CalTrans is empowered to open/close 

or reconfigure the managed lanes or eliminate 

tolls as deemed needed to support TIM. The 

I-15 system was built with a variety of technology and manual based systems at entry 

points to help address these issues including:

• DMS.

Figure 39. Photo. Effective clearance may 

be challenging in managed lanes with no 

shoulders and physical barriers, such as this 

zipper lane in New York City.

Source: FHWA
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• Gates.

• Pop up lane delineators.

• In-pavement lane guidance lights.

• Maintenance vehicles that drive the express lane after a lane reversal has occurred to ensure

the lane is clear and safe.

I-35W (Twin Cities Metropolitan Area, MN)

The Priced Dynamic Shoulder Lane system has overhead DMS and lane control/variable speed 

limit gantries at 1⁄2 mile spacing that allow easy closure of the managed lane and/or open the bus 

shoulder lane for general use. The TMC has the authority to close the managed lane or direct 

traffic to/from the managed lane and eliminate tolls as they deem necessary to support TIM.

4.6 CLEARANCE AND RECOVERY

Clearance and recovery comprise the final stages of the typical TIM process. Clearance involves 

removing wreckage, debris, or any other elements of a traffic incident that disrupt the normal 

flow of traffic. The impacts of an incident can extend beyond the managed lanes to the general 

purpose lanes and other parallel roadways in the regional transportation network. Therefore, 

improving clearance procedures could have positive effects including: minimizing motorist 

delay, enhancing the safety of responders and travelers, and minimizing the loss of revenue.

Recovery involves evaluating what the long-term impacts of an incident may be and identifying 

what recovery actions might be needed to mitigate those impacts. The ultimate goal of recovery 

is to restore the roadway capacity to its previous condition before the incident occurred, and to 

have the managed lane fully operating, collecting tolls if applicable, and providing premium 

service to eligible users. Recovery actions include:

• Clearing debris.

• Assessing damage.

• Repairing damaged infrastructure.

• Restoring traffic flow.

• Restoring the roadway to its previous condition.

TMCs provide unparalleled support to the quick clearance and recovery of traffic incidents by 

coordinating with responders to support any needs for additional resources such as tow trucks, 

medical support, environmental response, or other assistance.

In a managed lane environment several factors may provide challenges to quick incident clearance, such as accessibility of the incident scene and coordination among various responding 

agencies. To facilitate the clearance of an incident, managed lane operators may use managed 

lanes to divert traffic, and lane control signs to indicate which lanes are open and closed. After 

clearing the incident, normal operation of the managed lane facility resumes and signage returns 

to normal.
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Effective clearance and recovery protocols are critically important to the success of priced managed lanes 

because the longer an incident is on the roadway the 

less revenue is collected. If priced managed lanes are 

not providing an enhanced traveling experience, then 

motorists will not see its advantage and not be motivated 

to use them.

4.7 SYSTEM AND CORRIDOR MANAGEMENT

Previous sections in this chapter discussed TMC activities related to the typical TIM process. Those sections 

were primarily directed at actions that will occur at 

or near the scene or on the affected facility. Although 

system and corridor management is not part of the 

typical TIM process, it is a real-time response activity 

that can be implemented depending upon the functionality of the TMC.

A significant incident on a major limited access facility containing a managed lane will quickly 

affect and be affected by traffic conditions. TMCs have a variety of transportation management 

strategies and tools that can be used at a system and corridor level to reduce the traffic that will 

use a managed lane facility during an incident and encourage travel around the incident.

The current USDOT Integrated Corridor Management (ICM) Program is directed at integrating 

travel in corridors and provides a forward looking example of the wide variety of transportation 

management options that can be implemented for this purpose. While most TMC sites in the 

United States do not have all the capabilities to fully implement TIM from an ICM perspective at 

this time, most sites have many of the tools.

The strategies include:

Lane Control Signals

Use devices such as lane control signals and signs to 

implement or warn of lane closures, or reduced speed 

limits, or to close lanes well in advance of the scene.

Figure 40. Photo. Use of lane 

control signals to close lanes on 

the I-35W PDSL in Minneapolis.

Source: Adam Froehlig

Figure 41. Photo. Signs displaying 

travel times via private vehicle 

and public transit can encourage 

modal shift during incidents.

Source: Adam Froehlig

Ramp Metering

Modify ramp metering signal timing to reduce traffic 

volumes entering the facility.
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Traveler Information

TMCs can use systems such as 511, DMS and Highway Advisory Radio (HAR) across the 

corridor to alert travelers of the incident and the best way to avoid the related congestion.

Arterial Traffic Signal Timing Adjustment

TMCs can adjust signal timing on adjacent frontage roads, arterials and local streets to accommodate increased traffic on these facilities as traffic diverts.

Park and Ride Status and Modal Transfer

In some areas, TMCs have access to the unused capacity of nearby Park and Ride lots and can 

post DMS messages advising travelers they can change travel modes if parking is available.

Traffic Diversion

Where formal traffic diversions are implemented, TMCs can use DMS and other travel information devices to advise of the diversion and trail blaze motorists through the diversion route.

Travel Times

Where detection information is available, TMCs can use DMS and other travel information 

devices to advise travelers of comparative travel time route alternatives. This allows travelers to 

make their own assessment of any need to change route, mode or time of travel.

Expanded Motorist Assist Patrols

As congestion extends further from the affected managed lane facility, TMCs can adjust the 

times and roadways of coverage of their motorist assist patrols to focus them on the area most 

affected and help keep those facilities moving at optimum efficiency.

In the context of the corridor-level strategies, a single TMC will rarely have the capability to 

implement all the strategies across an entire corridor. The TMC will need to coordinate with 

numerous adjacent TMCs and agencies to accomplish a true corridor effect, which is consistent 

with the concept of ICM.

The following are examples of effective TIM-related corridor management strategies for 

managed lanes:

I-35W (Twin Cities Metropolitan Area, MN)

This managed lane system includes a variety of systems that are used to manage traffic at the 

system and corridor level. An Active Traffic Management (ATM) system covers the entire 

system and includes Intelligent Lane Control Signs at half-mile spacing that provide the means 

to open and close lanes or implement reduced speed advisories to support incident management 

activities. They also can adjust ramp meter timing consistent with congestion levels. Traffic data 
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from the facility is fused at the TMC such that traveler information can be provided across the 

corridor through DMS or 511.

I-495 HOV Lanes (Long Island, NY)

The INFORM TMC (state TMC for Long Island) monitors and manages the entire corridor using 

a variety of devices including DMS, ramp meters, and HAR. The full detection coverage that is 

installed in the corridor allows them to advise travelers of travel times immediately ahead as well 

as on alternate routes. The TMC controls the traffic signals on the I-495 frontage roads and can 

adjust signal timing in the event of a major incident.

4.8 TIM RESPONSE AND SUPPORT CHECKLIST

This checklist can be used by TMCs and/or operators of managed lanes to identify the real-time 

response activities and support actions that TMCs can take to support TIM in managed lanes. It 

will help in the understanding of which unique aspects of TIM response and support are applicable, or are potentially applicable, to their managed lane facility. This checklist could be used 

by operators of managed lanes to identify gaps in their TIM response or support functionalities 

that could lead to improvements in operation if addressed. 
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TMC Real Time Response Activities 

 and Support Checklist

Shared Operations Responsibilities

Determine entities involved

Contact information and point-of-contacts of 

each entity

Incident Detection and Verification 

Detect and confirm incident

Gather incident details from public input, ITS 

components, and responder reports

Scene Management and Control During 

Incidents in Managed Lanes

Scene Management Activities

Provide traveler information

Determine site selection and monitoring

Communication with responders and follow the 

evolution of response plan and actions

Dispatch support such as motorist assist patrols for 

scene management and clearance

Coordinate, if necessary, with agencies responsible 

for opening access to support responder ingress 

and egress

Traffic Control Activities

Coordinate with responders to develop traffic 

control plan

Support traffic control plan implementation via 

dispatch of support resources such as traffic 

response teams

Coordinate, if necessary, with agencies responsible 

to open access to the managed lane for 

traffic diversion

If present, adjust or coordinate the adjustment of 

movable barriers to support needed traffic flow

Where available, open the use of special use lanes 

such as HOV or shoulder lanes to improve traffic 

flow around the scene. 

Incident Response 

Dispatch the appropriate personnel/equipment 

Activate the appropriate communication links

Disseminate information

Management of Vehicle Access 

During Incidents in Managed Lanes

Manage vehicle eligibility

Manage pricing

Manage access control

Clearance and Recovery 

Coordinate with responders to support any 

needs for additional resources 

Implement System and Corridor 

Management Strategies and Systems

Lane control signals Traffic diversion

Ramp metering Display travel time 

information on DMS Traveler information

Expand/relocate Arterial signal timing motorist assist 

Park and Ride status patrol services 

Figure 42. Checklist. TMC Real Time Response Activities and Support Checklist.

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CHAPTER 5—CASE STUDIES

This chapter evaluates how the best practices related to TMC-based TIM are applied to several 

existing managed lane facilities in the United States. 

The case studies presented in this guidebook provide a level of insight into the combinations 

of best practices that can be implemented, why some best practices were implemented versus 

others, and the considerations that go into choosing best practices for implementation. 

As part of the research for this guidebook, the operations of eight managed lane facilities in the 

United States were reviewed. After the information was collected, three of the eight managed 

lane facilities were chosen for a more in-depth presentation in the guidebook. The eight facilities 

investigated by the project team included: 

1. Long Island Expressway (I-495) HOV Lanes (Long Island, NY).

2. I-35W Priced Dynamic Shoulder Lane (PDSL) System (Twin Cities, MN).

3. I-10 Katy Freeway Managed Lanes (Houston, TX).

4. I-95 Express Lanes (Miami, FL).

5. I-93 Contraflow HOV Lane (Boston, MA).

6. I-15 Express Lanes (San Diego, CA).

7. I-85 Express Lanes (Atlanta, GA).

8. I-495 Express Lanes (Fairfax County, VA).

Table 2 presents an overview of the eight managed lane facilities and the TIM best practices 

employed by each. 
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Technology and Communications

Established protocols related to incident communications 3 3 3 3 3 3 3 3

Data sharing agreements among agencies - detector data, video feeds, 

usage statistics 3 3 3 3 3 3

Interagency Relations and Coordination

Interagency agreements established with response agencies 3 3 3 3 3 3 3 3

Interagency agreements established with other transportation agencies 3 3 3 3 3

Managed Lane Enforcement Patrols

Manual enforcement / moving violations 3 3 3 3 3 3 3 3

Automated enforcement 3 3 3 3

Dedicated police patrols 3 3 3 3 3 3 3 3

Dedicated service patrols 3 3 3 3 3

TMC Resources

Recovery of some TMC operating costs from toll revenue 3 3 3 3

Toll revenue fully supports TMC operating costs 3 3

TIM Operational Considerations are incorporated into in the Design of Managed Lanes

Managed lane control software 3 3 3 3 3 3

Managed lane access and separation treatments 3 3 3 3 3 3

Planning Processes and Documents related to Managed Lanes

TMC operational considerations incorporated into planning processes 3 3 3 3 3 3 3 3

Shared Operations Responsibilities

Managed lanes / general purpose lanes operated by different 

transportation agency or entity 3 3 3

Multiple TMCs with TIM jurisdiction on corridor 3 3 3 3

Incident Detection and Verification 

Detect and verify incident from TMC 3 3 3 3 3 3 3 3

Incident Response 

Coordination of incident response from TMC 3 3 3 3 3 3 3 3

Pre-positioned response and recovery vehicles 3 3

Dedicated safety service patrols for managed lanes 3 3 3 3 3

Northern Virginia I-495 Express Lanes

Atlanta I-85 Express Lanes

San Diego I-15 Express Lanes

Boston I-93 Contraflow HOV Lane

Miami I-95 Express Lanes

Houston Katy Freeway Managed Lanes

I-35W Priced Dynamic Shoulder Lane

Long Island Expressway HOV Lanes

Table 2. TIM Best Practices Comparison for Eight Managed Lane Facilities.
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Table 2. (Cont.) TIM Best Practices Comparison for Eight Managed Lane Facilities.

Northern Virginia I-495 Express Lanes

Atlanta I-85 Express Lanes

San Diego I-15 Express Lanes

Boston I-93 Contraflow HOV Lane

Miami I-95 Express Lanes

Houston Katy Freeway Managed Lanes

I-35W Priced Dynamic Shoulder Lane

Long Island Expressway HOV Lanes

Management of Vehicle Access During Incidents in Managed Lanes

Adjusting vehicle eligibility during incident 3 3 3

Adjusting pricing during incident 3 3 3 3 3

Closing managed lanes remotely from TMC 3 3

Remotely closing access points from TMC 3 3 3 3 3 3 3

Scene Management and Traffic Control Activities

Select location, establish, maintain effective incident scene 3 3 3 3 3 3 3 3

Coordinate interagency response to open access points to scene 3 3 3 3

Adjust or coordinate the adjustment of movable barriers to support 

needed traffic flow 3 3

Open the use of special use lanes such as HOV or shoulder lanes to 

improve traffic flow around the scene 3 3 3 3

System and Corridor Management Strategies and Systems

Lane control signals 3 3

Ramp metering 3 3 3 3 3

Traveler information (DMS / HAR / 511) 3 3 3 3 3 3 3 3

Arterial signal timing 3 3

Post diversion information on DMS 3 3 3 3 3 3 3 3

Post travel times 3 3 3 3 3 3

Expand/relocate motorist assist patrol services 3 3 3 3 3 3 3 3

Clearance and Recovery

Coordinate with responders to support any needs for additional resources 3 3 3 3 3 3 3 3

Many of the best practices are currently implemented on managed lane facilities in the United 

States. Some of the findings from the investigation are as follows: 

• All managed lane facilities have communication protocols established for incident communications and interagency agreements with responder agencies.

• Interagency agreements between transportation agencies were needed only when managed

lanes were operated by a different entity than the general purpose lanes.

 The most detailed and formal interagency agreement was between the I-495 

Express Lane operator and VDOT, as the managed lanes are privately operated.
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• All facilities have some form of dedicated police patrols for the managed lanes and use those

resources for manual enforcement and moving violation enforcement.

 In some cases, the dedicated patrols are solely responsible for the managed 

lanes, while in other cases, police resources are shared with the general 

purpose lanes. 

 On priced managed lane facilities, dedicated police resources may require 

special equipment that utilizes toll tag readers and/or license plate scanners 

linked to the toll system.

• Service patrols covered all managed lane facilities, however only a select few had dedicated

service patrols for the managed lanes. Facilities with dedicated service patrols were either

privately operated, had pre-positioned vehicles such as tow trucks ready to respond to incidents due to tight lane geometry, or were operated by a toll agency with a dedicated fleet of

service patrol vehicles used for other facilities in addition to the managed lanes.

• Most entities that collect tolls used toll revenue to support TIM, but only two entities fully

fund their TMC from toll revenue. These entities maintain their own TMC exclusively for

the managed lane system (I-495 Express) or for the managed lane system and other toll roads

(Houston). Most other agencies use toll revenue to support TMC operations, but the TMC

has shared responsibility with other facilities besides tolled roads and managed lanes.

• Some form of managed lane control software was in use on priced managed lane facilities.

All facilities use some form of software for TIM purposes.

• Managed lane facilities that involved physical construction took operational considerations

into account during the design phase.

 Facilities that were conversions from HOV lanes (I-85), or fit into an existing 

right-of-way (I-93 Contraflow HOV Lane) have several design considerations 

for TIM, but since these facilities were designed to minimize capital costs, the 

TIM related design features are not the ideal features that would be incorporated 

into a managed lane facility built from scratch. 

 In all cases, the TMC was involved in operational planning for the facilities. 

• When the managed lanes are operated by a different agency as the general purpose lanes,

there are likely to be multiple TMCs with jurisdiction over a corridor. One TMC may have

primary responsibility for general purpose lanes, and the other for managed lanes.

 In some cases, multiple agencies are co-located within one TMC, and an 

agency’s staff may be present at multiple TMCs. This is the case in Houston, 

where the managed lane operator has staff in its own TMC and in TxDOT’s 

TranStar TMC. 

• Managed lanes on longer corridors may have multiple TMCs involved depending on the

coverage area of the TMC. The I-95 Express Lanes are covered by separate TMCs in MiamiDade and Broward Counties, respectively.
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• Only two managed lane facilities rely on pre-positioned response and recovery vehicles.

These facilities (I-15 and I-93) utilize physical barriers that cannot easily be breached or

crossed by response vehicles, so vehicles are located inside the lanes.

 Other agencies use dedicated service patrol vehicles for the managed lanes that 

have a designated “beat”, or patrol route within the managed lane network. This 

method is helpful where there is no shoulder available to pre-position vehicles. 

These vehicles on a patrol route are valuable sources of information for incident 

detection and verification. Response vehicles can cross or breach barriers if 

necessary to reach an incident. 

• Three managed lane facilities adjust eligibility restrictions: I-85 in Atlanta, I-35W in Twin

Cities, and I-15 in San Diego. The restriction is implemented in HOT lanes by removing

eligibility for toll-paying vehicles to enter and retaining the existing HOV restriction, rather

than altering the HOV restriction threshold.

• All but one agency with priced managed lanes can adjust pricing in response to an incident.

The exception is Houston’s managed lane facility, which adjusts the variable tolls based on a

set time schedule.

• Lanes can be closed remotely from the TMC on most managed lane facilities by adjusting

electronic signs at entrances to the lanes, though compliance is not ensured without police

or incident responder assistance. San Diego and Minnesota have designated resources for

closing lanes: lane control signals or pop-up devices activated from the TMC.

• All agencies without any form of physical barrier between the managed and general purpose

lanes, in addition to California (using designated access points) specifically cited the ability

to open managed lanes or shoulders to general traffic if needed during an incident.

• Ramp metering is present on most, but not all managed lane corridors.

• Two managed lane facilities (Long Island and Houston) specified the ability to regulate

arterial signal timing on some parallel diversion routes during an incident.

• All but two agencies have some corridor travel time information posted on DMSs.

• All TMCs can give traveler information, diversion information, and have the ability to

dispatch additional support for the incident scene and the corridor.

The above summary provides an overview of the practices used on a sampling of managed lane 

facilities throughout the United States. Three of these examples are highlighted in more detail 

in the following sections: Minnesota’s I-35W HOT/PDSL, Houston’s Katy Freeway Managed 

Lanes, and Virginia’s I-495 Express Lanes. Each case will be described in detail, and will focus 

on a certain aspect of TIM from the TMC in a managed lane environment. 

5.1 CASE STUDY 1: MINNESOTA’S I-35W HOT/PRICED DYNAMIC SHOULDER 

LANE AND ATM SYSTEM

Minnesota’s Department of Transportation (MNDOT) operates a part-time HOT lane facility on 

I-35W south of downtown Minneapolis. In the northbound direction, the HOT lane is extended 
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into downtown Minneapolis as a “Priced Dynamic Shoulder Lane” (PDSL). This managed lane 

facility is operated by the state DOT, so there are no interagency coordination needs between 

transportation agencies. The portion of the corridor where the PDSL is located does not have 

adequate shoulders, as the left shoulder is used by the PDSL and there is no right shoulder. As 

a result, MNDOT has deployed state of the art ITS resources on this managed lane facility and 

in the TMC with use of an Active Traffic Management (ATM) system. The ATM system gives 

MNDOT enhanced TIM capabilities for adjusting lane use, speed limits, and access to/from the 

managed lanes from the TMC. These capabilities are generally not found on most other managed 

lane facilities. 

Overview

Access Restriction

HOT (peak), open to general traffic (HOT Lane, off-peak), operates as a shoulder (PDSL, 

off-peak)

Physical Separation

Painted line/painted buffer

Location

The I-35W Managed Lane System is approximately 18 miles long and runs in both directions 

between Burnsville to the south and the City of Minneapolis to the north. The southern section 

of the system includes 15 miles of HOT lanes with one lane in each direction. On the northbound 

side, the managed lane system is extended an additional 3 miles into downtown Minneapolis 

through a Priced Dynamic Shoulder Lane (PDSL).

Design Type

HOT Lanes: the HOT lanes are 12-feet wide and have a reaction area on the left varying from 2 

to 10-feet separating the lane from the barrier as well as a 2-foot buffer on the right established 

by a painted double white line where there is no access and a single skip line at access points 

(see Figure 40).

PDSL

The PDSL section uses the existing shoulder and is generally 12-feet wide with a 2-foot buffer 

on the left separating it from the barrier. The PDSL is separated on the right from the general 

purpose lanes by a single yellow pained line. Access to and from the lanes is continuous.

General Purpose Lanes

The right shoulder of the general purpose lanes is generally 12-feet wide but is limited in the 

PDSL area to about two feet. In areas where the right shoulder is limited there are emergency 

pull offs about every one half mile.
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Source:

FHWA

Vehicle Eligibility

Free access to the managed lanes (HOT and PDSL) is limited to vehicles with 2 or more passengers (HOV 2+), transit and motorcycles. Single occupant vehicles with toll transponders may 

use the lane for a charge. The cost is variable depending upon congestion levels in the general 

purpose lanes.

Operations

The Minnesota Department of Transportation (MNDOT) is the owner/operator agency of the 

system including the tolling element of the system. The HOT lanes typically operate from 6 AM 

to 10 AM and 3 PM to 7 PM Monday – Friday. The HOT lanes are open to general traffic at all 

other hours. The PDSL operates from 6 AM to 7 PM Monday – Friday. The PDSL lane is used 

as a shoulder at all other times. MNDOT can adjust the specific times of operation at its discretion. During periods of heavy traffic, the PDSL is sometimes left open beyond the 7 PM closure 

time. The PDSL can also operate on weekends depending upon traffic demand. At the request of 

MNDOT’s snow and ice coordinator, the PDSL will be left open during overnight hours to allow 

vehicle traffic to disperse anti-icing chemicals. 

Figure 43. Illustration. I-35W PDSL HOT lane.

Additional Special Characteristics Affecting TIM

Bus Shoulder Use

Aside from the PDSL area where there is no right shoulder, buses are permitted to use the right 

shoulder as a travel lane when speeds fall below 35 MPH on the other lanes. When using the 

shoulder, buses are limited to traveling no more than approximately 15 MPH faster than vehicles 

in the adjacent travel lane.
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Winter Weather and Snow Removal

The Twin Cities area typically receives large amounts of snow accumulation during the winter 

season. The winter weather is a significant generator of incidents. The increase in lane miles, 

reduction in shoulder space, and addition of pull offs on the roadway segments with managed 

lanes all add to the snow removal requirements. Shoulders are no longer available for temporary 

snow storage in many locations, the added lanes will require an additional plow, and the pull offs 

require special equipment that can fit and maneuver into and out of the pull offs. Thus, there are 

significant additional costs for snow removal, as there are many segments where the snow must 

be blown into dump trucks and transported off the highway.

TIM State of the Practice Related to the Managed Lanes

Operation and Management

MNDOT owns and operates the managed lane system including the tolling element of the 

system. The system is monitored and managed from the MNDOT TMC in Minneapolis as part 

of their overall traffic management responsibilities for all state highways in the area. MNDOT

contracts out the fiscal/administrative aspects of the toll system. MNDOT has overall responsibility for both toll and traffic operations and can override pricing and/or open managed lanes to 

general traffic if conditions dictate. 

Traffic/Incident Management (Surveillance/Control - Detection/Verification)

The managed lanes are fully equipped with detectors and cameras for traffic monitoring 

purposes. In addition there are ramp meters controlling access to the overall freeway based on 

congestion levels. The entire system is also covered by an Active Traffic Management (ATM) 

system. The ATM includes Intelligent Lane Control Signs (ILCS), which are overhead signs 

located at about one-half mile spacing which provide speed harmonization, lane control, and 

electronic tolling information. The ATM provides a number of incident management capabilities 

including opening/closing lanes and slowing/smoothing traffic speeds.

Traveler Information

A variety of tools are used to notify the public of conditions that may affect the HOT lane, such 

as incidents, construction, or diversions. These include the DMS and ILCS as well as a 511 

system. In addition, MNDOT has a partnership with a local radio station that broadcasts traffic 

information every 10 minutes, or more often as needed in the event of a large scale incident. 

Enforcement

Enforcement on the system is provided by the Minnesota State Patrol. The State Patrol provides 

resources for routine enforcement and MNDOT contracts with the State Patrol to provide extra 

enforcement on the system during the HOT lane hours of operation. There is a dedicated pool of 

officers who undergo special training in the specifics of traffic enforcement and incident management for the managed lane system. Patrol vehicles are equipped with mobile reader devices that 

allow them to ascertain whether a vehicle has a toll tag.
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Response/Scene Management

The State Patrol is responsible for response to incidents on the system. Other emergency 

response such as fire and EMS are provided by the appropriate local agencies. MNDOT also 

has motorist assist patrols (FIRST) that patrol the system to provide routine assistance and can 

respond to incidents and assist with scene management or push vehicles off the travel way. 

Towing is provided by local area towing companies as requested by the State Patrol under a 

tow zone system that considers factors such as equipment, hours of operation, response time, 

and reliability.

Minnesota has Quick Clearance laws in place to support rapid clearance. MNDOT and the State 

Patrol have a formal Open Roads Policy. In the event of an abandoned vehicle, the FIRST patrols 

have authority to initiate the tow. The fact that buses may use the right shoulder to expedite their 

travel increases the importance of quick clearance of incidents affecting the shoulder.

Diversions

Because the HOT and PDSL have shoulders and access to the general purpose lanes diversion 

is not a special issue from an incident management perspective. In general, standard procedures 

are followed when an incident occurs in the managed lanes. As indicated previously, MNDOT 

can direct general purpose traffic into the managed lanes or waive tolls if necessary, but this is 

rarely done.

Institutional Coordination

TIM

MNDOT has a robust TIM program in cooperation with the State Patrol as well as local 

responders as appropriate. Elements of the program include routine coordination meetings, joint 

training, post incident reviews, and planning for special events. 

Figure 44. Photo. ATM system on I-35W in Minneapolis.

Source: Adam Froehlig
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Agreements

As indicated previously, there are two significant agreements affecting incident management of 

the system:

• An Open Roads agreement between MNDOT and the State Patrol.

• A funding agreement with the State Patrol for additional enforcement patrols on the

managed lanes.

Resources/Funding

Resources for operating the managed lanes are generally the responsibility of MNDOT and 

include both traditional funds as well as toll revenues.

Design/Construction/Maintenance Coordination

There is close cooperation among the MNDOT Design, Construction, and Maintenance Offices 

with regard to the operational considerations of the managed lanes.

Other Issues

MNDOT has a number of research projects underway to improve system operations/management including:

• Researching how to modify the advisory speed limit during inclement weather.

• Researching the extent to which motorists see and react to the message signs.

Summary of TMC Role in Managed Lane TIM

The MNDOT TMC is responsible for managing and monitoring the PDSL HOT lane. The TMC 

covers the entire system including the general purpose lanes with cameras, ramp meters, and 

detectors in order to effectively detect incidents. Since the PDSL system and adjacent general 

purpose lanes are equipped with an ATM system, the TMC has enhanced incident management 

capabilities such as the ability to remotely open/close lanes and slowing/smoothing traffic speeds 

with variable speed limits. The ATM also includes ILCS overhead signs, which are used along 

with DMS, 511 system, and a partnership with a local radio station in order to disseminate 

incident information to the public. 

The TMC dispatches a dedicated pool of officers with special incident management training that 

can effectively utilize the enhanced TIM tools that are available on this corridor. In addition, 

MNDOT TMC operates FIRST motorist assist patrols that routinely patrols the PDSL HOT 

lane to respond to incidents and assist with scene management. Since the shoulders are used by 

PDSL and buses, quick detection and clearance of incidents is the goal of the MNDOT TMC in 

operating this corridor. The TMC has the authority to direct general traffic into managed lanes 

and waive tolls, and it can also direct managed lane traffic into the general purpose lanes, if 

necessary. Communication of this change can occur using existing ATM and ILCS infrastructure 

controlled by the TMC. 
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Findings

MNDOT’s extensive use of ATM is unique among the managed lane facilities examined in this 

project. In the future, it is likely that more facilities using ATM will be constructed to improve 

TIM and managed lane operations. ATM may be a mitigation strategy for managed lane facilities constructed in a constrained environment where the geometrics are not ideal from a TIM 

perspective, such as reduced or narrow shoulders. This will help maximize the use of available 

roadway space while minimizing the disruption from an incident. 

5.2 CASE STUDY 2: HOUSTON’S KATY FREEWAY MANAGED LANES AND 

INTERAGENCY COORDINATION

The Katy Freeway Managed Lanes are located on I-10 west of Houston, Texas. The facility is 

operated as a HOT lane facility during peak hours and as an Express Toll Lane facility during 

other times where all vehicles pay for access. The entire Katy Freeway corridor underwent 

significant reconstruction when the managed lanes were built, and is now one of the widest 

freeway corridors in the country. As a result of this reconstruction, the purpose-built Katy 

Freeway Managed Lanes have nearly ideal geometrics, with full shoulders on both sides adjacent 

to a flexible post barrier separating them from the general purpose lanes. 

Of interest to planners about the Katy Freeway Managed Lanes is the shared operating responsibility for the corridor. The managed lanes are operated by the Harris County Toll Road Authority 

(HCTRA), while the general purpose lanes and frontage roads are operated by the Texas DOT 

(TxDOT). HCTRA operates tolled facilities in and around Houston, while TxDOT is the primary 

operator of freeways within the region. Each agency operates its own TMC. HCTRA’s TMC 

covers all of its tolled facilities in the region. TxDOT is the lead agency at the TranStar TMC, 

which co-locates many of the transportation providers in the Houston area under one roof. 

Included as part of the TranStar TMC are: TxDOT, Harris County, HCTRA, the City of Houston, 

and the Houston area’s transit agency, Metro. In addition to transportation officials, public 

safety officials are located at the TranStar TMC, which has an emergency management function 

in addition to a transportation management function. As a result of HCTRA’s participation in 

TranStar, the agency has staff at two different TMC’s in the Houston area. Their TranStar presence will enhance their ability to coordinate with other transportation agencies during a major 

incident, while minor incidents only affecting the managed lanes can be handled from their own 

TMC. This arrangement actually requires some intra-agency coordination between its TMC staff 

located in the two different TMCs. 

Overview

Access Restriction

HOT (peak hours), Tolled (non-peak hours)

Physical Separation

Plastic “candlestick” post barrier with full shoulders on both sides
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Location

The I-10 Express Lanes extend 12 miles in both directions in the center of Interstate 10 in 

Houston, Texas. 

Design Type

There are two 12-foot wide lanes in each direction, separated directionally by a concrete barrier. 

The express lanes are separated from the general purpose lanes by a plastic post barrier with 

12-foot wide shoulders on both sides of the post barrier (see Figure 42). Direct access to/

from the express lanes is provided at each end as well as through slip ramp type openings in the 

channelization at 3 intermediate points. In addition, there is direct access provided from a Park 

and Ride lot as well as a transit center. There are three toll gantries located within the system 

between access/egress points that serve as designator lanes to sort HOV users from toll tag users. 

Source: Wikimedia Commons User Socrate76

Figure 45. Photo. I-10 Katy Freeway managed lanes with 

plastic post barrier and full shoulders on either side.

Vehicle Eligibility

Free access to the express lanes is limited to peak hours for vehicles with 2 or more passengers 

(HOV 2+), motorcycles and exempt vehicles such as metro buses and police. Single occupant 

vehicles with tags are allowed anytime at a toll price that changes based on time of day. Eligible 

vehicles must also pay the posted toll price during non-peak hours.

Operations

The Harris County Toll Road Authority (HCTRA) is responsible for the operation of the express 

lanes including all traffic operations and toll operations. TxDOT is responsible for the operation 

of the general purpose lanes. The system operates 24/7. Designated peak hours are 5 AM to 11 

AM and 2 PM to 8 PM, Monday through Friday. 
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Additional Special Characteristics Affecting TIM

Toll Gantries

Traffic must sort into one of two lanes at the toll gantries – one lane for HOV-eligible traffic and 

one for single occupant vehicles with toll transponders. The gantry locations provide an area 

where enforcement vehicles can park to observe entering vehicles.

Plastic Post “Candlestick” Barrier

The posts can be removed to facilitate diversion to/from the express lanes. They are also flexible 

enough that vehicles from the general purpose lanes can physically drive over them if necessary 

to divert traffic in the event of an incident. 

Enforcement/Incident Scene Management

Two adjacent 12-foot shoulders, one on each side of the plastic post barrier, provide ample space 

for enforcement and incident management activities.

Source: David James Corcoran

Figure 46. Photo. The Katy managed lanes (or Katy Tollway) operate as HOT 

during peak hours and ETL at other times, and have a maximum possible toll.

Concurrent Operators

The fact that two separate agencies operate lanes within the system provides special challenges 

related to traffic management and enforcement coordination, as both agencies need to be 

involved during any incident where diversion is involved. 

TIM State of the Practice Related to the Managed Lanes

Operation and Management

The Harris County Toll Road Authority (HCTRA) is responsible for the operation of the express 

lanes including all traffic operations and toll operations. TxDOT is responsible for the operation 

of the general purpose lanes. The Harris County Police provide for enforcement on the express 

lanes. HCTRA monitors and manages the express lanes from their own 24/7 TMC/Incident 
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Management Center which includes a robust dispatch system. TxDOT monitors and manages the 

general purpose lanes from the Houston TranStar TMC.

Traffic/Incident Management (Surveillance/Control - Detection/Verification)

The entire system is equipped with a traffic monitoring and management system including 

cameras and DMS as well as message signs at the designator lane toll gantries. There are two 

sets of cameras on the system, one for the express lanes/HCTRA and one for the general purpose 

lanes/TxDOT. Cameras, detector information and DMS messages and control are coordinated to 

provide seamless operation.

Traveler Information

A variety of tools are used to notify the public of conditions that affect the express lanes, such 

as incidents, construction, or diversions. These include the DMS as well as a 511 system. As 

indicated previously, HCTRA shares detector and speed information with the Houston TranStar 

TMC, and TranStar merges the information and acts as the single source for regional traveler information. 

Enforcement

The Harris County Police provide enforcement on the express lanes. There are 13 patrols 

dedicated to enforcement on the express lanes. The enforcement costs are treated as part of the 

overall system operations costs and hence come from the toll revenues. In general, the City of 

Houston Police Department provides for enforcement on the general purpose lanes. The police 

have mobile data terminals in their vehicles that allow them to enforce violations related to toll 

tag accounts. The toll gantries provide police with safe locations for parking to perform enforcement activities. 

Response/Scene Management

The Harris County Police provide incident response on the express lanes. In general, the City of 

Houston Police Department provides incident response on the general purpose lanes. The City 

of Houston provides fire and EMS response on both systems. The HCTRA is able to dispatch 

any of these resources from their TMC. The HCTRA has four dedicated motorist assist patrols 

that monitor the express lanes – two for each direction. These patrols support incident response 

and scene management. Their resources and capabilities include response vehicles with message 

boards, towing, and hazardous material spill kits. The Harris County Police are aware of the 

impact that incidents in the general purpose lane can have on the express lanes. They are often 

the first enforcement vehicles on the scene for general purpose lane incidents and will get 

involved to initiate and/or supplement response there. Texas has “Steer It/Clear It” and “Move 

Over” laws to support quick and safe incident management. The HCTRA and Harris County 

Police have formal quick removal policies and can respond within 5 minutes and clear lanes 

within 10 to 15 minutes for normal incidents.
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Diversions

HCTRA and Harris County Police have the authority to divert traffic from the general purpose 

lanes into the managed lanes and waive tolls. The frequent entry and exit points on the express 

lanes as well as quick incident response and wide shoulders make the need for diversion from the 

managed lanes a rare occurrence. In the event of a major closure the police will not only perform 

traffic control on the freeway but will also place enforcement personnel at the traffic signals at 

the frontage roads/arterials.

Institutional Coordination

TIM

HCTRA has a robust TIM program in cooperation with the Harris County Police as well as local 

responders as appropriate. Elements of the program include routine coordination meetings, joint 

training, post incident reviews, and planning for special events. 

Inter-agency Coordination/Agreements

HCTRA, TxDOT and Metro have a formal “tri-party” agreement that covers interagency coordination related to the express lanes. In general, the parties defer to HCTRA to operate and manage 

the lanes on a daily basis. The three agencies coordinate more frequently if there are changes 

to the system or operations that are being considered. In addition, the Harris County Police and 

HCTRA have entered into an agreement with a local wrecker service to ensure quick response, 

standard rates and equipment capability.

Resources/Funding

In general, resources are provided by HCTRA and Harris County Police and operations are 

funded from the toll revenues.

Design/Construction/Maintenance Coordination

There is close cooperation among these offices due to internal procedures and as provided by the 

tri-party agreement.

Other Issues

These issues were also identified:

• Future systems should be designed such that all HOV/tag type enforcement can be done in 

entrance/exit areas where speeds are low. It is very difficult to conduct this enforcement at 

highway speeds.

• The use of plastic posts as the express lane separator has both advantages and disadvantages. 

A key advantage is that the barrier can be temporarily removed or driven over to provide 

emergency access or diversion. A disadvantage is that lack of a strong physical separation can 

allow errant vehicles to encroach into adjacent lanes. 
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Summary of TMC Role in Managed Lane TIM

There are two 24/7 TMCs involved in incident management on the facility; the HCTRA TMC 

and the Houston TranStar TMC. The two TMCs are located separately. The HCTRA TMC is 

responsible for monitoring and managing the express lanes, whereas the Houston TranStar TMC 

is responsible for monitoring and managing the general purpose lanes. The two TMCs operate 

the whole system as a seamless facility, allowing both to coordinate operations and response 

during any incident.

The HCTRA TMC is staffed and operated by HCTRA personnel. It focuses on incident management on the express lanes. The Houston TranStar TMC focuses on multiagency operations and 

management of the region’s transportation system. TranStar is a partnership among the principal 

transportation and emergency management agencies in Harris County, including: 

• Texas Department of Transportation (TxDOT).

• Metropolitan Transit Authority of Harris County (Metro).

• Harris County, including:

 Traffic & Transportation Group.

 Harris County Toll Road Authority.

 Office of Homeland Security & Emergency Management.

• The City of Houston.

The two TMCs coordinate TIM activities related to the Katy Freeway. Their roles include:

• Monitoring all lanes for operational status and incidents.

• Operation of ITS detection, DMS, and CCTV devices.

• Dispatch of motorist assist and incident response units for their respective operational responsibilities.

• Dispatch and/or coordination with enforcement and emergency responders.

• Authority to divert traffic during incidents between the express and general purpose lanes.

• Control of access to the express lanes to manage traffic entry volumes during incidents.

• Incident management coordination, as well as with operational partners such as Metro and

the City of Houston.

• Sharing of traffic detection information and CCTV/DMS devices through the TranStar TMC

to provide for optimum system monitoring and management during incidents.

• Distribution of incident-related traffic condition traveler information. HCTRA distributes

information locally via DMS while TranStar merges information and distributes it regionally

to the public and media.

• Multiagency TIM related operational agreements including the HCTRA/Harris County Police

Quick Clearance policy as well as the HCTRA/TxDOT/Metro agreement governing express

lane operations.

• Multiagency TIM program implementation including inter-agency training and debriefings.
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The existence of both the HCTRA TMC and TranStar TMC to provide and coordinate focused 

local managed lane incident management activities, as well as to integrate response and traveler 

information on a regional level, provides a unique and powerful tool for effective TIM on the 

Katy Freeway corridor. 

Findings

The Katy Freeway Managed Lanes have very strong interagency coordination as one of their key 

operating strategies. As a result, the Katy Freeway corridor operates as a seamless transportation 

entity, despite two public agencies having jurisdiction over different parts of the same roadway 

cross section. Each entity has procedures for responding to an incident on their portion of the 

roadway, and there are designated procedures in place for incidents that affect both operators. 

Each side understands their role and responsibilities prior to the occurrence of an incident, so 

that any incidents can be resolved as quickly as possible. The interagency arrangements used on 

the Katy Freeway corridor which allow co-location of some staff resources at one TMC are ideal 

for facilitation of interagency coordination, provided both agencies are on board and willing to 

very closely coordinate on a day-to-day basis. 

5.3 CASE STUDY 3: FAIRFAX COUNTY, VIRGINIA’S I-495 EXPRESS LANES AND 

PRIVATE SECTOR OPERATORS

The I-495 Express Lanes in Fairfax County, Virginia are operated by the private firm Capital 

Beltway Express (CBE). This firm is a joint venture between a construction firm and a publicly 

traded firm that operates toll facilities in the United States and abroad. The private ownership 

of the I-495 Express Lanes introduces some additional complexities into the operation and 

TIM processes. 

Figure 47. Photo. I-495 Express Lanes on the Capital 

Beltway in Fairfax County, VA, near Washington, DC.
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CBE entered into a very comprehensive operating agreement with the Virginia DOT (VDOT) 

related to operation of the I-495 corridor. Each agency’s roles and procedures are very clearly 

spelled out in the form of an operating procedures manual which covers a wide variety of potential scenarios. The scenarios contain specific thresholds for when a procedure is to be implemented. For example, some procedures are related to the issuance of an emergency declaration by the 

state government. 

Capital Beltway Express operates its own TMC, called the HOT Operations Center (HOT-OC). 

This TMC has direct data links to VDOT’s Smart Traffic Center for the Northern Virginia area, 

and it is via links that incident data and other ITS data is shared. A specified format is used for 

communication of incident information, and a protocol is in effect for notification from one 

agency to the other when an incident on one agency’s facility is detected by the other. A specified 

arrangement for cost-sharing and which agency takes the lead for specific incident management 

are also included as part of the agreement. 

Overview

Access Restriction

HOT

Physical Separation

Express lanes are separated from regular lanes by white flexible posts and a 4-foot painted buffer.

Location

The I-495 Express Lanes extend 14 miles along the Capital Beltway between the Springfield 

Interchange and just north of the Dulles Toll Road in Fairfax County, Virginia.

Design Type

There are 4 high-occupancy toll (HOT) lanes; 2 lanes in each direction (see Figure 45). The 

express lanes have left shoulders on each side.

Vehicle access is provided at 11 entry/exit points to and from other highways and major side 

routes. There is no access between the HOT lanes and the general purpose lanes except at the 

end points. 

Vehicle Eligibility

Free access to the express lanes is allowed for vehicles with 3 or more passengers (HOV 3+) 

using E-ZPass Flex transponders. In addition, motorcycles, transit buses, and emergency vehicles 

can utilize the express lanes for free. Vehicles carrying 1 or 2 people have to pay a toll to ride in 

the express lanes. The tolling is dynamic based on the distance traveled and traffic congestion 

conditions in order to keep the express lanes congestion-free. There are 8 toll gantries in each 

direction, and tolls are collected electronically using E-ZPass/E-ZPass Flex transponders.
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Figure 48. Photo. The I-495 Express Lanes are operated by a private 

firm and are separated from the publicly owned and heavily congested 

general purpose lanes by a 4 foot buffer with a plastic post barrier.

Operations

Capital Beltway Express (CBE) is a private firm responsible for the traffic management and 

operations of the express lanes from their HOT Operations Center (HOT-OC). The HOT-OC 

operates 24/7. On the other hand, the Virginia DOT is responsible for the operations of the 

general purpose lanes, and has their own ITS assets located in their TMC. The Virginia State 

Police (VSP) provides for enforcement for HOV 3+ on the express lanes.

TIM State of the Practice Related to the Express Lanes

Operation and Management

Regardless of the incident location (express or general purpose lanes), immediately following 

incident identification, the identifying agency shall notify 911 emergency dispatch. For incidents 

on the express lanes that do not impact the general purpose lanes, CBE takes responsibility for 

dispatching its Safety Service Patrol and clearing the incident, as well as providing incident 

data to VDOT. For incidents on the general purpose lanes only, VDOT takes responsibility for 

dispatching its Safety Service Patrol and clearing the incident regardless of where it started. For 

those incidents that affect both express and general purpose lanes, VDOT oversees the response 

and coordinates with the emergency first responders. 
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Response to Unplanned Incidents

In addition, for all unplanned incidents related to the express lanes, CBE shall transmit the 

following data to VDOT using the data connection between their respective TMCs:

• Location of the incident (by mile marker and nearest interchange).

• Lane(s) impacted.

• Severity of incident.

• Number of vehicles involved.

• Number of disabled vehicles.

• Whether there are any injuries.

• Whether hazardous materials are involved.

• Estimated time for response to incident.

• Estimated duration of incident.

• Updates regarding the status of incident.

Figure 49. Chart. Response to unplanned incidents along I-495.

Traffic/Incident Management (Surveillance/Control—Detection/Verification)

In addition to the pan-tilt-zoom (PTZ) CCTV cameras, the entire system is equipped with automated incident detection cameras that are capable of detecting lane blocking events, wrong way 

vehicles, false alarms, and medial/opposite direction locations. Moreover, it is equipped with the 

DYNAC GIS-based incident response system with multi-cast digital video to quickly and more 

accurately pinpoint incidents. Both CBE and VDOT provide each other access to the streaming 

videos and ITS data collected from the express and general purpose lanes, respectively.

Traveler Information

A variety of tools are used to notify the public of conditions that affect the express lanes, such 

as incidents, construction, diversions. These include the dynamic message signs (DMS) at each 

entrance, 495 Express website, VA511 website, and mobile apps. Typically, CBE and VDOT’s 

communications teams are engaged only for those incidents categorized as “Level 3”, which is 

the most severe type of on-road incidents. For incidents in the express lanes or express access 
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ramps, CBE manages the crisis communications. For incidents in the general purpose lanes or 

ramps, VDOT manages crisis communications. For incidents blocking both general purpose and 

express lanes, VDOT oversees a coordinated communications response with CBE’s assistance.

Diversions

Diversions can be performed using the designated access points in the system. In addition, as part 

of any declared emergency evacuation routing, CBE will follow VDOT’s directives delivered by 

authorized representatives with respect to suspension of tolling, allowing VDOT to take control 

of the express lanes, diversion of traffic into the express lanes, controlling the CBE’s DMS 

messaging for declared emergencies, and compliance with Virginia Department of Emergency 

Management’s evacuation plans.

Institutional Coordination

Interagency Coordination/Agreements

As mentioned earlier, CBE (via its HOT-OC) and VDOT (via its Northern Virginia TOC) operate 

express and general purpose lanes, respectively. Since CBE is a private entity and VDOT a 

public sector transportation agency, coordination between VDOT and the private operators of 

the managed lanes is unique. Both agencies have formal agreements in place to facilitate coordination between the public and private sector, including a Joint Operating and Maintenance 

Protocols document. The Joint Operating and Maintenance Protocols address a wide variety of 

coordination issues including:

• An organizational structure and protocol for ongoing coordination through a management 

committee for non-real time coordination, and via contact between VDOT’s Transportation 

Operations Center and CBE’s Traffic Control Supervisor for real time coordination.

• VDOT’s right to temporarily override DMS messages during a declared emergency or a 

significant incident involving fatalities.

• Situations in which each entity will implement a Unified Command Team to coordinate 

response to severe incidents.

• VDOT’s ability to suspend tolling in the event the HOT lanes are designated for use as 

emergency evacuation routes or as an alternate route for diversion from other state highways 

or the general purpose lanes in the event of an emergency or significant incident involving 

fatalities. VDOT will have no financial liability for this action.

The operation system protocols require advance notifications from CBE to VDOT for any 

planned or unplanned maintenance/outages on the express lanes in relation to traffic detection, 

communications, traffic signals and intersection control, power and lighting systems. VDOT is 

also required to notify CBE with similar activities on the general purpose lanes. 

Summary of TMC Role in Managed Lane TIM

The I-495 Express Lanes in Virginia are unique in that the managed lanes are operated by the 

private sector and run immediately adjacent to publicly operated general purpose lanes. This 
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provides unique challenges to coordination and operation of the roadway corridor, since each 

entity has different operating strategies, resources, and equipment. A detailed agreement by both 

the private and public sector entities must be in place to ensure that each operator will keep the 

other informed, and that the transportation network operates seamlessly from the perspective of 

the public. 

The HOT Operations Center (HOT-OC) of the Capital Beltway Express (CBE) is responsible 

for management and operations of the express lanes, while VDOT’s Northern Virginia TOC 

is responsible for operation and management of the general purpose lanes. The CBE HOT-OC 

has CCTV and Automated Incident Detection cameras covering the whole system as well as 

DYNAC GIS-based incident response system to quickly and more accurately pinpoint incidents. CBE HOT-OC also has dedicated safety service patrols that are responsible for clearing 

incidents on the express lanes in coordination with Virginia State Police. CBE and VDOT have 

formal agreements and joint operation and maintenance protocols that facilitate the response and 

management of incidents on both sets of lanes.

The information in the agreement focuses on which entity is responsible for TIM and specific 

communication protocols for when one operator detects an incident in the other operator’s lanes. 

Diversions between the express lanes and general purpose lanes are possible using existing ramp 

infrastructure. VDOT has ultimate responsibility and the ability to control ITS assets of both 

entities for large incidents that affect both the general purpose and managed lanes, as well as 

during declared emergencies. 

Findings

Although there are few privately operated managed lane facilities in the United States, many 

more are expected in the future as transportation agencies discover the benefits of public-private 

partnerships. Careful negotiation of operating agreements is critical to the success of these 

facilities, and will ensure that the unique needs of the public sector agency and private entity are 

met during both normal operations and incidents. The I-495 Express Lane model of prior interagency planning resulting in a comprehensive operating procedures document is one that can be 

followed by other agencies desiring to establish successful public-private partnerships. 
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CHAPTER 6—CONCLUSIONS

Managed lanes are growing in popularity as a transportation strategy to address increasing 

congestion in urbanized areas. This guidebook provides a framework for successful development 

and implementation of a TIM program using a TMC in the managed lane environment.

The role of TMCs in TIM on managed lanes is an important topic for transportation professionals and incident responders with jurisdiction over managed lane facilities to understand. 

While much is known about TIM, TMC operations, and managed lanes, the confluence of these 

subjects is a specialized topic worthy of its own guidebook. Managed lanes present a unique 

operating environment for TIM activities, due to the unique physical designs, the presence of 

enhanced ITS assets, the potential need to coordinate between multiple transportation agencies 

operating in the same corridor, and financial considerations for TIM in priced managed lanes.

The TMC plays an important role in the operation of managed lanes. In order for managed 

lanes to function properly, the facility must operate reliably with minimal downtime. The TMC 

supports this by properly preparing for TIM activities that will occur on the managed lanes, and 

then by supporting the real-time TIM activities that occur during an incident.

Preparation activities should begin early in the conceptual stage of the managed lanes in order 

to ensure that the facility is designed with TIM activities in mind and that the TMC’s assets 

will work properly alongside existing ITS assets in the region. Interagency coordination plans, 

an enforcement plan, and communication protocols between the stakeholders should be established prior to the opening of the managed lanes. Having a properly prepared TMC will ensure 

that when an incident occurs, the TIM activities involving multiple agencies occur seamlessly 

and smoothly.

During an incident, TIM procedures are conducted in the specialized managed lane environment. 

If multiple agencies are involved, each should have designated responsibilities. Detection and 

verification of an incident can often occur more easily in the managed lane environment due 

to robust deployment of ITS technology, but the response may be complicated by difficulty in 

accessing the managed lanes. In some cases, special coordination between the TMC and ground 

crews will be necessary to allow for provision of access to the managed lanes, diversion, and 

scene management at the incident site. Traffic control at an incident scene can be enhanced 

in the managed lane environment using an ATM system, which will allow for immediate and 

direct control directly from the TMC. Ideally, traffic control will occur on a system and corridor 

level, to effectively manage traffic long before it arrives at the incident scene. One of the most 

important goals of TIM in managed lanes is quick clearance and recovery in order to allow the 

managed lane facility to return to normal operations and minimize the loss of revenue. The TMC 

is instrumental in coordinating and directing all TIM activities and supporting the goals of quick 

detection, response, and clearance to an incident.

The guidebook presented an overview of the eight case studies that were examined during the 

course of researching managed lane facilities. Three case studies were examined in greater depth 

in the guidebook to highlight areas where the managed lane facility performed especially well 
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in the context of using the TMC for TIM purposes. The first case study highlighted the use of an 

ATM system to manage an incident scene in a constrained environment. It was found that ATM 

can be used as a mitigation tool for managed lane facilities that do not have ideal geometrics. 

The second case study highlighted interagency coordination where two different public sector 

transportation agencies manage the corridor from two TMCs. It was found that the robust coordination agreements in place among multiple TMCs along the same stretch of freeway allows for 

extremely efficient TIM practices. The third case study examined a privately operated managed 

lane facility existing in the same right-of-way as publicly operated general purpose lanes. It was 

found that private and public TMCs can operate as partners and allow for successful roadway 

operations and TIM practices. Privately operated managed lane facilities are expected to grow 

as transportation agencies notice the benefits of public-private partnerships.

The TMC is instrumental in coordinating and directing all TIM activities and supporting 

the goals of quick detection, response, and clearance to an incident.
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GLOSSARY OF TERMS

GLOSSARY OF TERMS

511

The national 3-digit telephone number for traveler information used by most states to provide 

real-time traffic and transit information about current operation status, highway conditions, 

weather advisories, and emergency warnings.

Active Traffic Management (ATM)

Method used to manage the flow of traffic on busy major highways to increase mobility and 

safety, and reduce congestion. Strategies include: variable speed limits, hard-shoulder running 

and overhead variable message signs.

Adjustable/Variable Speed Limits 

Speed limit signs located along the roadway that can change to direct motorists to reduce speed 

when necessary. These signs can be adjusted by TMC personnel. 

Adjusting vehicle eligibility requirements 

Strategy in which an existing vehicle occupancy requirement can be increased, an eligibility 

requirement could be implemented where none normally exists, or a HOT facility could suspend 

access for those paying tolls and restrict entry to HOVs only.

Automated Enforcement 

Enforcement used on managed lanes that reduce the need for manual enforcement such as law 

enforcement patrols. Strategies including automatic license plate recognition are utilized. 

Automatic License Plate Recognition (ALPR)

Surveillance method that uses optical character recognition on images to read license plates 

on vehicles. 

Bus Lane 

Lane that only buses are permitted to use.

Busway 

A road, or section of a road, set apart exclusively for buses.

Closed Circuit Television (CCTV)

The use of video cameras to view traffic on roadways. TMC operators have the ability to control 

these cameras to pan, tilt, or zoom to show different views of the road.
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GLOSSARY OF TERMS

Computer-Aided Dispatch (CAD)

Program used by TMC personnel to gather information about an incident and dispatch the 

appropriate emergency personnel by taking into account the type of incident and responder 

agency needed.

Contraflow

A contraflow lane uses a lane in the off-peak direction of travel for travel in the peak direction, 

and is typically created using a movable barrier to separate the two directions of travel.

Continuous Access Lane 

Motorists may enter and exit the lane at any location. May operate as a typical freeway lane with 

some form of access restriction, can be closed or operated as an additional general purpose lane.

Department of Transportation (DOT)

A government department responsible for construction, operation, and maintenance of highways, 

railways, and other forms of transportation. 

Diversions

Implemented in one of two ways where general traffic can be diverted into the managed lanes, or 

managed lane traffic can be diverted into the general purpose lanes. 

Dynamic Message Sign (DMS)/Variable Message Sign (VMS)

Message signs used on roadways to communicate different types of information including 

incidents and travel times. TMC operators are responsible for entering the real-time information 

into the system to transmit these messages. 

Express Toll Lane (ETL)

A priced managed lane that charges a toll for access to the lane. The toll rate is variable in order 

to manage congestion. Rate adjustments may be on a set schedule or dynamically based on realtime traffic conditions. 

Eligibility Requirements Suspension 

Strategy used to open the managed lanes to all traffic.

Facility Closure 

Changeable message signs, signals, or gates at the entrances to the managed lane facility that is 

controlled by the TMC to completely close the facility to traffic. 
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GLOSSARY OF TERMS

Federal Highway Administration (FHWA)

A division of the United States Department of Transportation which oversees the construction, 

maintenance and preservation of the nation’s highways, bridges and tunnels.

High Occupancy Toll (HOT) Lane 

A priced managed lane where an occupancy requirement is set and those vehicles meeting that 

requirement can travel for free, and vehicles not meeting the occupancy requirement must pay 

a toll to travel in the lane. The toll rate for vehicles not meeting the occupancy requirement is 

variable in order to manage congestion.

High Occupancy Vehicle (HOV) Lanes 

Lane with a vehicle restriction for the exclusive use of vehicles with a driver and one or more 

passengers, including carpools, vanpools, and transit vehicles. May operate at all times or only 

during peak hours.

Highway Advisory Radio (HAR)

Radio used to broadcast information to motorists.

Incident Management (IM)

Strategies designed to restore normal service operation safely and as quickly as possible 

following an incident while minimizing impacts. 

Intelligent Transportation System (ITS)

A broad range of wireless and wire line communications-based information and electronic 

technology applications used by different modes of transport and traffic management.

Lane Control Signals 

Green arrow and red “X” signals that appear over lanes to indicate if a lane is open or closed. On 

certain managed lanes, TMC personnel are able to remotely close and re-open lanes. 

Managed Lanes 

Highway facilities or a set of lanes where operational strategies are proactively implemented and 

managed in response to changing conditions.

Manual Enforcement 

This type of enforcement involves placing law enforcement personnel along the managed lane to 

monitor traffic and stop motorists who violate policies.
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GLOSSARY OF TERMS

Painted Buffer 

Double white line or a wider painted “buffer area” used to separate a managed lane from the 

general purpose lanes, with openings to allow legal entry/exit points.

Painted Buffer with Electronic “Invisible” Barrier 

Same as the painted buffer with the addition of an electronic system. This system can include 

a series of cameras, license plate readers, and/or toll transponder readers to detect when a car 

enters or exits the managed lane between legal entry/exit points.

Permanent Physical Barrier 

A physical barrier used to separate the managed and general purpose lanes permanently. 

Designed so that the managed lanes will operate as a completely separate roadway from the 

general purpose lanes. 

Plastic Post Barrier 

Flexible plastic posts placed inside a painted buffer area to separate managed lanes and general 

purpose lanes. 

Ramp metering 

Used to reduce the volume of traffic entering the roadway.

Regional Architectures (RA)

Describes what type of TIM systems and services will be deployed and the information that is 

exchanged between them. Also identifies data and communications standards that apply.

Reversible Roadway 

Entire roadways that can reverse direction and are typically built to handle large directional 

peaks in traffic volumes.

Road Weather Information System (RWIS)

Used to obtain weather information.

Roadway Management 

Use resources to effectively manage the affected roadway and arterials during incidents.

Safety Service Patrol 

Motorist assistance safety/service patrol programs that help keep incident scenes safe, clear 

incidents more quickly, and assist other emergency responders at incident scenes. 
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GLOSSARY OF TERMS

Scene Management

Strategies that involve the establishment of a safe and effective area where responders can deal 

with the incident response and clearance.

Shoulder Lane 

Right or left shoulder lane is used as a full-time or part-time managed lane.

Strategic Plan 

Identifies vision, goals and objectives for the managed lane TIM activities as well as deployment 

strategies, benefits and costs, funding plans and high level performance measures. 

Toll Rate Adjustment 

Dynamically adjusting toll rates that can increase the price for use of the managed lanes in order 

to discourage all but the highest value trips from utilizing the facility.

Traffic Control 

Implementing effective traffic control at and around the incident management scene can 

help increase the safety of the responders as well as reduce the potential for secondary 

vehicle accidents.

Traffic Incident Management (TIM)

The process of coordinating the resources of a number of different partner agencies and private 

sector companies to detect, respond to, and clear traffic incidents as quickly as possible to 

reduce the impacts of incidents on safety and congestion, while protecting the safety of on-scene 

responders and the traveling public.

Transportation Management Center (TMC)

Center that provides real-time monitoring of the highway, detecting incidents, coordinating/

supporting response and distributing traveler information. Normally open 24 hours a day, 7 days 

a week but are at least open during peak periods.

Zipper Barrier 

A semi-permanent physical barrier for lane separation that can be moved by a special 

mobile machine. 

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ACKNOWLEDGEMENTS

ACKNOWLEDGEMENTS

We would like to acknowledge the following Transportation Management Centers Pooled Fund 

Study (TMC PFS) members for their contributions, support, and technical guidance during 

this project.

Elizabeth Birriel Florida DOT

John McClellan Minnesota DOT

Mark Demidovich Georgia DOT

Paul Keltner Wisconsin DOT

Angela Jacobs FHWA
122

U.S Department of Transportation

Federal Highway Administration

Office of Operations

1200 Jersey Avenue, SE

Washington, DC 20590

Office of Operations Web Site

http://www.ops.fhwa.dot.gov

December 2014 

FHWA-HOP-14-022