A Review of HOV Lane Performance and 

Policy Options in the United States 

FINAL REPORT 

Under Contract To: 

December 2008 
Notice 

This document is disseminated under the sponsorship of the Department of Transportation in the interest 

of information exchange. The United States Government assumes no liability for its contents or use 

thereof. This document does not constitute a standard, specification, or regulation. 

The United States Government does not endorse projects or manufacturers. Trade and manufacturers’ 

names appear in this document only because they are considered essential to the object of this 

document. 

 -i- 
Technical Report Documentation Page

1. Report No. 

FHWA-HOP-09-029 

2. Government Accession No. 3. Recipient's Catalog 

No.

4. Title and Subtitle 

A Review of HOV Lane Performance and Policy 

Options in the United States 

5. Report Date 

December 2008 

6. Performing 

Organization Code 

7. Author(s) 

Mark Chang, Booz Allen Hamilton Inc.; John

Wiegmann, Booz Allen Hamilton Inc.; Andrew

Smith, HNTB; Claudia Bilotto, HNTB 

8. Performing Organization Report No. 

9. Performing Organization Name and Address 

Booz Allen Hamilton Inc. 

8283 Greensboro Drive 

McLean, Virginia 22102 

HNTB Corporation 

3715 Northside Pkwy NW 

Atlanta, GA 30327

10. Work Unit No. 

 

11. Contract or Grant 

No. 

 

12. Sponsoring Agency Name and Address 

Federal Highway Administration 

1200 New Jersey Avenue SE 

Washington DC 20590 

13. Type of Report and Period Covered 

Final Report 

14. Sponsoring Agency

Code 

HOTM, FHWA

15. Supplementary Notes 

Patrick DeCorla-Souza, FHWA Office of Operations, Office of Transportation Management, Contracting 

Officer's Technical Representative (COTR). 

The research was performed under contract to Booz Allen Hamilton. 

16. Abstract 

The report provides an assessment of performance of existing HOV lane facilities in the United States, 

and explores policy alternatives and effects related to conversion of existing HOV lanes to HOT lane 

operations. The report includes sketch planning tools for exploring policy alternatives, and is intended for 

an audience of transportation professionals responsible for planning, designing, funding, operating, 

enforcing, monitoring, and managing HOV and HOT lanes, and other stakeholders in policy decisions for 

improving HOV lane and highway mainline operations through conversion to HOT lanes. 

17. Key Words 

High Occupancy Vehicle, HOV Lane, HOV Enforcement, 

HOV Facility Enforcement, HOV Facility Design, HOV 

Planning, HOV Operations, HOT Lane, HOT Lane Policy, 

HOT Lane Use, HOT Lane Exemptions, HOT Facility 

Design, HOT Facility Tolling 

18. Distribution Statement 

No restrictions. 

19. Security Classif. (of this report)

Unclassified.

20. Security

Classif. (of this 

page) 

Unclassified.

21. No. of Pages 

48 

22. Price 

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

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FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Table of Contents 

EXECUTIVE SUMMARY..............................................................................................................1

SECTION 1: INTRODUCTION .....................................................................................................2

SECTION 2: OPERATIONAL DESCRIPTION OF THE NATION’S HOV LANES.......................4

SECTION 3: HOV OPERATOR SURVEY AND INTERVIEW RESULTS ....................................8

SECTION 4: POLICY OPTIONS EVALUATION TOOL.............................................................17

SECTION 5: CONCLUSIONS ....................................................................................................42

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FHWA Task 4 – Final Documentation 

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EXECUTIVE SUMMARY 

High-Occupancy Vehicle (HOV) lanes are common throughout the United States. There is a growing 

body of evidence suggesting that efficient and effective management of existing HOV lanes is both 

achievable and sustainable through applications including managed lanes and electronic toll collection. 

However, development and implementation of effective HOV strategy and policy has involved challenges 

that include planning and design issues, stakeholder concerns, and less than optimal performance. 

There is a need to obtain a better understanding of the experience and factors that contribute to 

successful HOV lane performance. 

HOV owners nationwide were contacted to discuss the performance of existing HOV lanes, if and why 

owners are considering policy changes, and what are the future expectations. Based on respondents 

representing 10 states and over 70 HOV facilities, the primary objectives of HOV lanes are to maximize 

person throughput, manage congestion, and provide an option for travel time savings and reliability. Over 

80 percent of respondents actively monitor system performance. Most respondents indicate that HOV 

lanes are currently meeting performance objectives. For HOV lanes that are not performing adequately, 

the primary concerns are overcrowding, low speeds, lack of a continuous system, and enforcement 

issues. 

The next study task involved assessing the impacts of pricing and other policy shifts on the operational 

performance of the nation’s HOV lanes. A sketch planning tool was developed to evaluate the effects of 

policy on operational performance and measures of financial feasibility. The tool involves conducting the 

following steps – 1) Assess existing HOV facility operations, 2) Define opportunities for HOV policy 

changes, 3) Evaluate potential impacts, and 4) Compare impacts relative to specified objectives. The 

sketch planning tool provided a quantifiable, useful approach to measuring the impacts of HOV policy 

changes on facility performance. 

Many HOV facility owners are interested in policy changes, often influenced by performance, political 

interest, and public opinion. Changing commute and congestion levels dictate the need to consider such 

policy changes on an ongoing basis. A policy options evaluation tool was developed to help HOV owners 

consider a range of potential policies, including changing occupancy requirements and managed lane 

pricing. How the performance objectives are defined greatly influences the optimal policy changes that 

should be considered. Every HOV lane is unique in its demand and operations, and the locally-specific 

context must be carefully taken into account. 

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FHWA Task 4 – Final Documentation 

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SECTION 1: INTRODUCTION 

High-occupancy vehicle (HOV) lanes are reserved for vehicles with a driver and one or more passengers. 

In some cases, other vehicles are also exempted (permitted in the HOV lanes). Examples include

motorcycles, transit and charter buses, emergency and law enforcement vehicles, low emission vehicles, 

hybrid or alternative fuel vehicles, and/or single-occupancy vehicles (SOVs) with a toll. These lanes,

which usually run parallel to general-use highway lanes, have been implemented in over 30 US metro

areas since they first appeared in the late 1960s and early 1970s. HOV lanes were originally conceived

as a means to encourage carpooling and therefore increase person throughput in the transportation

system, among other potential benefits like providing reliable transit trip times and increasing roadway 

capacity while benefiting air quality. The restrictions in these lanes limit traffic demand, which can provide 

travel time savings along a corridor when compared to adjacent general-use lanes. This travel time

advantage is an incentive to drivers to form carpools in order to bypass congestion. Today, there are

nearly 350 HOV facilities operating or planned across 20 states. 

Unfortunately, HOV lanes do not always provide the expected advantages. Situations frequently arise in

which the facility operates with too many (or too few) vehicles during lane operation periods, leading to a

number of potential problems. Empty-lane syndrome, the popular term for a condition in which HOV lanes 

are underutilized, is one common concern. Peak-hour congestion in HOV lanes is another. Striking the

proper utilization balance is a challenge for all HOV operators. Add to that the issues that stem from peak 

directional flows, and the efficient operation of HOV facilities becomes even more complicated. Agencies 

seeking to avoid or mitigate these lane performances problems will often consider and implement HOV 

lane policy change as a solution. . 

Not all policy changes are motivated by operational difficulties, however. Other motivations for such 

change include maximizing system throughput, revenue generation (in the case of high occupancy toll 

(HOT) lanes), and legislative mandate. Opportunities for getting more vehicles through a particular 

corridor almost always exist, and changes to HOV policies can help to realize throughput gains. 

Implementation of tolling on HOV lanes can also provide revenue for lane maintenance or expansion, 

transit improvements, or other purposes in the region. Legislation can also drive policy change. HOV 

operators are currently required to consider policy changes if average speeds in the HOV lanes drop

below 45 mph for 90 percent of the time over a consecutive 180-day period during the weekday peak 

periods (23 USC. 166 (d)(2)(B). And some operators have had to adjust their policies based on laws that 

allow hybrid vehicles to use the lanes without charges. Finally, Federal initiatives, such as the Value 

Pricing Pilot Program and the Urban Partnership Agreement, encourage pricing experimentation and

have in some cases included policy changes to existing HOV lanes to serve as tests leading to wider

implementation. 

This study examined the performance of HOV lanes with regard to the goals and objectives under which 

existing HOV lane facilities were deployed. Also addressed are factors that can best contribute to the

success of HOV lanes, through targeted and focused outreach to HOV operators. Identification and

improved understanding of these factors can contribute to effective policy change decisions that improve 

performance of existing and future HOV facilities. 

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FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

The study consisted of the following four tasks: 

• Task 1: Prepare a Detailed Work Plan. This task involved conducting a project kick-off meeting and

preparing a detailed work plan that articulates the approach and strategies employed to achieve the

study’s goals and objectives. The work plan outlined key topic areas and described an overall

approach to assembling the information critical to understanding the relationship between operations, 

policy, and performance. 

• Task 2: Assemble Available Data and Perform Analysis of the Performance of Existing HOV

Lanes in the United States. The purpose of this task was to develop an understanding of HOV lane

success factors and what forces will raise expectations of HOV lanes in the future. This task 

consisted of the following subtasks: Conduct Inventory of HOV Programs and Operations; Develop 

Screening Criteria for Identification of Critical Partners; Assess the Performance of HOV Investments; 

and Prepare Task Documentation. 

• Task 3: Assemble Available Performance Data and Analyze the Impacts of Increasing

Occupancy Requirements. The purpose of this task was to develop a policy options evaluation tool

in order to quantify the effects of HOV policy changes on operational performance and measures of 

financial feasibility. This task included the following subtasks: Organize and Consolidate Critical 

Success Factors; Develop Policy Drivers and Performance Targets; Develop Policy Options 

Evaluation Tool; Use the Policy Options Evaluation Tool to Quantify the Impacts to Operational 

Performance and Financial Impacts; Establish Relationships between HOV Lane Operating

Performance and Policy Drivers; and Prepare Technical Documentation. 

• Task 4: Final Documentation. This task involved packaging the main study outcomes into a Draft

Final Report for FHWA review, then a Final Report that incorporates comments received. 

The remainder of this report is organized according to the following sections: 

• Section 2: Operational Description of the Nation’s HOV Lanes. Contains summary information

from the HOV Lane Compendium, prepared as a deliverable for Task 2, documenting the basic 

characteristics of current and proposed High-Occupancy Vehicle (HOV) lanes throughout the United

States. This includes information on the number of facilities, date opened and status, operating

characteristics, and operating performance. 

• Section 3: HOV Lane Operator Survey Results. Provides findings from an online survey of HOV

lane operators and in-depth interviews with a subset of HOV facility critical partners to discuss their 

experiences, challenges, and success factors. This includes information on system goals and

objectives, performance monitoring, HOV system performance, plans to revisit goals, HOV lane

operational policies and policy changes, policy change motivations, and policy implementation

success factors.

• Section 4: Policy Options Evaluation Tool. Describes the Policy Options Evaluation Tool for 

Managed Lanes (POET-ML), developed to help HOV owners consider a range of potential HOV lane

policies including changing occupancy requirements and managed lane pricing. This includes

information on the tool’s purpose, framework, user inputs, and evaluation of potential impacts. 

• Section 5: Conclusions. Provides the characteristics and lessons learned that increase the

chances for successful implementation of HOV lane policy changes. 

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HOV Lane Performance Project Draft Final Report 

SECTION 2: OPERATIONAL DESCRIPTION OF THE NATION’S HOV 

LANES 

The intent of the HOV Lane Compendium deliverable was to document the basic characteristics of 

current and proposed High-Occupancy Vehicle (HOV) lanes throughout the United States. Data sources

used were the HOV Facility Inventory (a database maintained by the FHWA HOV Pooled Fund Study, 

last updated in March 2007) and discussions with select HOV facility critical partners. 

Summary information from this compendium is provided next. This information is grouped into the

following subsections: Number of Facilities; Date Opened and Status; Operating Characteristics; and 

Operating Performance. The HOV Lane Compendium itself is provided as a separate deliverable. 

Number of Facilities 

By State. A total of 345 HOV facilities are contained in this inventory. California is the state with the 

most HOV facilities, at 88. This is followed by Minnesota with 83 facilities, Washington State with 41, 

Texas with 35, and Virginia with 21. 

By Region. The region with the most HOV facilities in the inventory is the Twin Cities (Minneapolis-St. 

Paul) with 83. This is followed by the San Francisco Bay Area with 47, the Puget Sound (SeattleTacoma) with 40, Los Angeles with 23, and Houston with 21. 

By Responsible Agency. The agencies responsible for the most HOV facilities in the inventory are the 

California Department of Transportation (Caltrans) and the Minneapolis DOT, both with 83. This is 

followed by the Washington State DOT with 38, the Metropolitan Transit Authority of Harris County in

Texas with 21, and the Virginia DOT with 19. 

Date Opened and Status 

Date Opened. The I-395 HOV lanes in Virginia between Washington DC and the Capital Beltway are 

listed as the oldest HOV facilities, having opened in 1969. Several more HOV facilities opened in the 

1970s. The majority of HOV facilities in the inventory began operation within the past 25 years (from the

early 1980s to present). 

Status. Of the 345 HOV facilities in the inventory, 301 (87 percent) are open and in operation. Ten 

facilities (3 percent) are being planned, 15 (4 percent) are in the design or environmental review phase,

14 (4 percent) are under construction, and the remaining five (1 percent) were constructed but are

currently inactive. 

Operating Characteristics 

Number of HOV Lanes. The vast majority of HOV facilities have one HOV lane in each direction. The 

only active facility with two HOV lanes in each direction is I-110 between Adams Blvd and SR 91 in Los 

Angeles, California. Seven other facilities with two HOV lanes in each direction are being planned, under 

construction, or operating – One in Florida: I-95 between downtown and the Golden Glades interchange 

in Miami; three in Texas: SR 183 between I-35W and Loop 12 in Dallas, Hempstead Highway between

SH 99 and I-610 in Houston, and SR 288 between SH 518 and US 59 in Houston; one in Utah: I-15

between Provo and I-215 in Salt Lake City; and two in Virginia: the I-495 Capital Beltway in the 

Washington DC region and the I-95/I-395 between Fredericksburg and Arlington. 

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Length. The longest active HOV facilities are I-95 between SR 112 and Gateway Blvd in Miami, Florida 

(116.0 lane-miles, 58.0 route miles) and I-405 in Los Angeles County, California (105.2 lane-miles, 52.6 

route miles). Two other HOV facilities are being planned or constructed that will exceed these in length

on a lane-mile basis: the I-495 Capital Beltway in the Washington DC region in Virginia (224.0 lane-miles, 

56.0 route miles), and I-15 between Provo and I-215 in Salt Lake City, Utah (128.0 lane-miles, 32.0 route 

miles). 

Type. The most common type of HOV facility is Concurrent (Median), with 187 facilities (54 percent) 

falling into that category. Only four HOV facilities are Concurrent (Right Side): the I-95 approach to the 

George Washington Bridge toll plaza in New Jersey and three SR 520 facilities in Washington State 

which will be converted to the inside lane when the SR 520 bridge is replaced. 

In the Twin Cities, Minnesota, 77 of the 83 HOV facilities in the region are bus-only shoulder lanes. In

Houston, Texas, 13 of the 21 HOV facilities in the region are concurrent lanes on one-way urban arterials. 

There are 37 reversible or contra flow HOV facilities nationwide. There are 15 HOV facilities that are 

separate roadways. The remaining HOV facilities are curb lanes, bus only lanes, other or unspecified. 

 

Separation. The most common separation used for HOV facilities is Painted Stripe, with 118 (34 

percent) falling into that category. There are 60 HOV facilities (17 percent) that use buffers. There are 45

HOV facilities (13 percent) that use barriers. Of those that use barriers, six are moveable barriers to 

facilitate reversible HOV lanes (H-1 in Honolulu, Hawaii; I-93 between Boston and Quincy in 

Massachusetts; I-278 between the Verrazano Bridge and Battery Tunnel in New York; I-495 between 

Maurice Ave and QM Tunnel in New York; and two I-30 facilities in Dallas, Texas – one that is open and 

another that is under construction). 

In the Twin Cities, Minnesota, the 77 bus-only shoulder lanes are separated by a traveled lane edge line 

with signage. In Houston, Texas, the 13 concurrent lane facilities on one-way urban arterials are

separated by a dashed line with “broken diamond” pavement markings. Standard dash lines are used for 

9 facilities, which are all arterials. 

Cones or pylons are used for two facilities in Honolulu, Hawaii (Kalanianaole Highway and Nimitz

Highway), one facility in Union City, New Jersey (I-495 contra flow bus only lane), and one facility in 

Weehawken, New Jersey (local approach ramp to the Turnpike toll plaza). The remaining HOV facilities 

do not have the separation method specified. 

HOV Eligibility. 185 of the HOV facilities in the inventory (54 percent) are purely 2+. There are 14

facilities (4 percent) that are purely 3+. There are two facilities that are 3+ during certain times of the day 

and 2+ during other times of the day – the I-10 El Monte HOV facility in Los Angeles, California and the

Nimitz Highway in Honolulu, Hawaii. 

There are six facilities that are open to 2+ HOV vehicles with no toll and to single-occupancy vehicles

(SOVs) with a toll (i.e., 2+ high-occupancy toll (HOT) lanes): SR 91 between Riverside County and 

Orange County in Los Angeles, California; I-15 between SR 163 and SR 56 in San Diego, California; two

in Denver, Colorado (I-25 between downtown and US 36, US 36 between Pecos St); and two in Salt Lake

City (I-15 between 600 North and 14600 South, I-15 between 14600 South and University Parkway). 

Three additional 2+ HOT facilities are being planned: two facilities on I-680 in the San Francisco Bay

Area, California and one on I-15 between 600 North and University Parkway in Salt Lake City, Utah. 

There are two facilities that are open to 3+ HOV vehicles with no toll and to 2+ HOVs and SOVs with a toll 

(i.e., 3+ HOT lanes), both in the New York City region: I-495 between Maurice Ave and QM Tunnel and I278 between Verrazano Bridge and Battery Tunnel. Four additional 3+ HOT facilities are in the planning

or construction phase: I-40 between Durham and Raleigh in North Carolina; SR 183 between I-35W and

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HOV Lane Performance Project Draft Final Report 

Loop 12 in Dallas, Texas; I-95/I-395 between Fredericksburg and Arlington in Virginia; and the I-495 

Capital Beltway in northern Virginia. 

Two facilities operate as 2+ HOT at certain times and 3+ HOT at other times, both in Houston, Texas: US

290 between I-10 and SH 6 and I-10 WB (SH 99 to I-610 & Studemont to CBD). 

Five toll plazas in the San Francisco Bay Area, California are free to either 2+ or 3+ HOVs during

weekday peak periods: the I-80 WB Bay Bridge (3+), the I-880 NB Bridge (3+), the I-80 EB Carquinez 

Bridge (3+), the SR 84 WB Dumbarton Bridge (2+), and the SR 92 WB San Mateo Bridge (2+). Three toll 

plazas in New Jersey are free to 3+ HOVs during weekday AM peak periods: I-95 approach to the

George Washington Bridge in Ft. Lee, 12th St approach to the Holland Tunnel in Jersey City, and local 

approach ramp to the Turnpike toll plaza in Weehawken. 

In the Twin Cities, Minnesota, the 77 bus-only shoulder lanes are restricted to buses only. There are 7 

other bus only facilities in other states. The remaining HOV facilities in the inventory do not have 

occupancy requirements specified. 

Special Fuel Eligibility. Several states allow hybrid or alternative fuel vehicles to use HOV facilities. In 

Arizona, owners of select hybrid vehicles may apply for special license plates that allow them to use HOV 

lanes. In California, owners of select hybrid vehicles were allowed to apply for license plate decals that 

allow them to use HOV lanes until 2011, capped at 85,000 decals (all 85,000 decals have been 

assigned). In Colorado, owners of select alternative fuel and hybrid vehicles may apply for license plate

decals and transponders that allow them to use HOT lanes with no fee, capped at 2,000 (the cap has not 

yet been reached). In Florida, owners of select hybrid vehicles may apply for license plate decals that

allow them to use HOV lanes. In New Jersey, drivers of select hybrid vehicles are allowed to use the 

Turnpike’s HOV lanes. In New York, owners of select hybrid vehicles may apply for license plate stickers

that allow them to use the Long Island Expressway’s HOV lanes. In Tennessee, owners of select hybrid

vehicles will be able to apply for license plate decals that allow them to use HOV lanes starting in January

2009. In Utah, owners of select hybrid vehicles may apply for special license plates that allow them to

use HOV lanes until December 2010. In Virginia, owners of select hybrid vehicles may apply for special 

license plates that allow them to use most HOV lanes in the state (except I-95/I-395 during weekday peak 

periods). 

Similar hybrid vehicle HOV legislation is currently being considered or has recently been considered in 

Connecticut, Georgia, Hawaii, Massachusetts, Michigan, Minnesota, Texas, and Washington State. 

Hours of Operation. 140 of the HOV facilities in the inventory (41 percent) operate 24 hours a day, 

seven days a week. This includes the 77 bus-only shoulder lane facilities in the Twin Cities, Minnesota.

156 facilities (45 percent) operate on weekdays only during the AM peak, the PM peak, or both. The 

remaining HOV facilities do not have hours of operation specified. 

Intermediate Access. 41 of the HOV facilities in the inventory (12 percent) allow continuous access,

primarily in Northern California, Houston Texas, and Washington State. 180 facilities (52 percent) allow 

some intermediate access. 26 facilities (8 percent) allow no intermediate access, including select 

facilities in Arizona, Southern California, Connecticut, Hawaii, Massachusetts, New York, and Dallas 

Texas. The remaining HOV facilities do not have intermediate access specified. 

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HOV Lane Performance Project Draft Final Report 

Operating Performance 

Utilization. Most of the HOV facilities in the inventory do not provide utilization data, so it is difficult to

make definitive statements. Of the HOV facilities with utilization data provided, the one with the highest 

number of peak hour persons in the HOV lanes is the Route 495 Lincoln Tunnel Bus Lane in New Jersey, 

with 23,500 vehicles in the AM peak. The facility with the highest number of peak hour vehicles in the 

HOV lanes is I-5 NB between Northgate and S Everett in the Seattle Puget Sound region in Washington

State, with 5,280 vehicles in the PM peak. 

Peak Hour Violation Rate. Most of the HOV facilities in the inventory do not provide peak hour violation 

rate data, so it is difficult to make definitive statements. Of the 86 HOV facilities with data provided, the 

range is from 1 percent to 43 percent. The highest reported peak hour violation rates are I-15 between 

SR 163 and SR 56 in San Diego, California (43 percent), I-35W SB between 66th St and Burnsville Pkwy

in the Twin Cities, Minnesota (37 percent), SR 54 EB between I-805 and SR 125 in San Diego, California

(28 percent), and seven facilities in the Washington DC region, either in Maryland or Virginia (ranging

from 17 to 28 percent). The other 76 HOV facilities with data provided reported peak hour violation rates

of 15 percent or less. 

Peak Hour Travel Time Savings. Most of the HOV facilities in the inventory do not provide peak hour 

travel time savings data, so it is difficult to make definitive statements. Of the 91 HOV facilities with data

provided, the range is from 0.4 minutes to 37 minutes. The highest reported peak hour travel time

savings are SR 85 NB in the San Francisco Bay Area, California (37 minutes), I-95 NB between Rte 234 

and I-495 in the Washington DC region, Virginia (35 minutes), I-880 SB between Marina Blvd and Mission 

Blvd in the San Francisco Bay Area, California (31 minutes), US 101 SB between San Mateo Co and

Cochrane Rd in the San Francisco Bay Area, California (30 minutes), and the I-10 El Monte HOV facility

in Los Angeles, California (28 minutes). Seven other facilities report travel time savings of 20 minutes or 

more – I-110 in Los Angeles, California; I-210 in Los Angeles, California; I-405 in Los Angeles, California; 

SR 85 SB in San Francisco, California; Rte 495 in New Jersey, I-66 EB in Virginia; and I-395 SB in

Virginia. 

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FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

SECTION 3: HOV OPERATOR SURVEY AND INTERVIEW RESULTS 

To understand the performance of HOV lane systems across the country, an initial survey of HOV lane 

operators was conducted in order to understand their goals, objectives, and current HOV lane

performance based on monitoring efforts. The survey also explored policy changes that have been 

implemented or are planned to be implemented on HOV systems, as well as the reasons for making

these changes and their impacts on lane performance. An online survey was developed and distributed to 

74 HOV contacts across the country utilizing the Federal Highway Administration (FHWA) HOV Pooled 

Fund Study Database and other HOV resources including the Transportation Research Board (TRB) 

Committee on HOV Lanes and the Texas Transportation Institute, as well as networks of HOV 

professionals. The survey generated 28 responses representing 10 states and approximately 73 HOV 

facilities. The survey was supplemented with a review of existing data and follow-up conversations with

additional HOV professionals and representatives of HOV operators. 

Following the initial survey and literature review, in-depth one-on-one interviews were held with a subset 

of HOV operators who have experience in implementing various policy changes to discuss their 

experiences, challenges, and success factors. The objective was to understand how actual policy 

changes have impacted lane performance and under what conditions policy changes might be

implemented in other areas to improve system performance. These discussions included representatives 

from Denver, Colorado; Houston, Texas; Minneapolis, Minnesota; Northern Virginia; San Diego,

California; and the Puget Sound Region of Washington State. 

Main findings from the survey and follow-up interviews are provided next. These findings are grouped

into the following subsections: System Goals and Objectives; Performance Monitoring; HOV System

Performance; Plans to Revisit Goals; HOV Lane Operational Policies and Policy Changes; Policy Change 

Motivations; and Policy Implementation Success Factors. The survey instrument and more detailed 

survey/interview comments are provided in a separate deliverable.

System Goals and Objectives 

Respondents have indicated that while many HOV systems do not have officially adopted goals and

objectives, most have goals and policies understood by operating and partner agencies and the urban 

areas of which they are part. Considerable similarity was found from one region to the next, incorporating

six common objectives: 

• Maximizing person throughput; 

• Managing congestion by improving system efficiency;

• Providing options for travel time savings and trip reliability; 

• Encouraging carpooling in peak periods; 

• Improving air quality; and 

• Supporting transit service and transit reliability. 

Figure 3-1 summarizes survey responses relative to the goals and the intent of HOV systems. Some 

areas also note that the addition of HOV lanes was a means to add system capacity to accommodate

regional growth under circumstances that will not permit the addition or expansion of general-use 

capacity. Others identify energy savings as an additional goal for their HOV systems. 

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FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Figure 3-1: Why did you add HOV lanes in your region? What are your HOV system goals? 

Performance Monitoring 

Eighty-two percent (82%) of survey respondents report that they monitor the performance of their HOV

lanes. In most cases, the HOV lane operating agency is responsible for monitoring efforts. In some cases,

partnerships with university research centers and third-party contractors or consultants are responsible for

monitoring efforts. Performance criteria for HOV lanes most frequently include throughput (vehicular

and/or person), travel time savings, and speed in the HOV lanes versus speed in the general-use lanes.

Level of service is monitored almost as frequently. Other responses indicate the collection and analysis of

data regarding accident rates, enforcement, transit performance and ridership trends, lane usage trends,

and public opinion. 

Performance measures and criteria generally relate to system goals and objectives. Therefore, systems 

identifying transit service as a priority, and/or are managed by a transit agency, may focus significant 

resources on monitoring transit-specific measures, while those who lack this focus do not. A measure

such as public opinion has become increasingly important on systems where a pricing component (HOT 

lanes) has been implemented on a previously free HOV lane. Although most HOV systems do not 

specifically track public opinion, the monitoring of performance measures that clearly demonstrate a 

marked difference between the number of persons and vehicles in the HOV lanes versus the general-use

lanes in an urban area, and the travel times and speeds in the HOV lanes versus the general-use lanes,

have helped to generate public buy-in and support for lane operations in some urban areas. Effective 

communication of these measures can also be used to demonstrate that a policy change may be 

necessary to better utilize HOV assets in locations where they are not performing effectively. 

Data collection methods vary from facility to facility and include both manual and automatic detection 

methods. Vehicle throughput (determined by traffic volume counts) and speed are typically collected

through automatic detection devices such as traffic sensors and loop detectors. Person throughput and 

occupancy rates are determined through manual counts and visual survey. Enforcement data and

violation rates are typically provided by the police or enforcement entity responsible for the HOV system. 

Travel time data collection frequently utilizes floating vehicle methods of collection by placing a

transponder or GPS unit in cars or buses utilizing the HOV system. Other information, such as the 

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HOV Lane Performance Project Draft Final Report 

number of hybrid vehicles that utilize an HOV system where this is permitted, may be collected from

enforcement data, manual counts, or hybrid registrations (where applicable) to track their utilization of the

system. This type of specialized information may not be regularly tracked, depending on available

resources, but may be collected if there is a reason for the operating agency to investigate a particular 

type of system use that could impact a proposed policy change. Frequency of data collection is somewhat 

dependent on the method of collection and how often the operating agency queries automatic collection 

systems. Automatic measurement methods may be ongoing, while manual counts take place once or

twice a year. Some agencies issue publicly available annual reports on system performance, while others 

have data available upon request. 

On HOT systems emerging throughout the country, a greater emphasis has been placed on performance

monitoring as resources, infrastructure, and technology that can be used for lane monitoring programs

are considered in initial system design, and the advent of pricing raises the importance of accountability 

to the public regarding lane performance. 

HOV System Performance

Seventy-five percent (75%) of survey respondents indicate that their HOV systems are achieving current

performance objectives. Those who indicate otherwise cite issues resulting from congested lanes, such

as too much demand during the peak period and resulting overcrowding issues, and low speed

differential between HOV and general-use lanes. Other performance issues include lack of a continuous 

system, “end of the line” issues such as bottlenecks where HOV lanes reconnect with general-use lanes, 

high violation rates, and low usage during enforcement periods. 

Underutilization, or “empty-lane syndrome,” is another common performance issue nationwide that has

led to policy changes on HOV systems. Inadequate speed differential is also noted in some areas as it 

relates to geometric design, where a buffer separation results in lane friction between the HOV lane and

the slower moving general-use lanes and impacts the HOV lane driver’s tendency to drive at free-flow 

speeds. 

Plans to Revisit Goals 

Of the 28 respondents, 21 have revisited or plan to revisit system goals based on changes since the initial

implementation of their HOV system (see Figure 3-2). The two most frequent reasons for a policy change 

were cited as political interest and performance. Public opinion was the next most frequent motivation for 

revisiting goals, with other motivating factors including legislative changes, a desire for revenue, or a shift 

in regional goals or policies. Some facilities have changed goals based on a shift to HOT lanes, or due to 

a regional examination of pricing options. One respondent indicated that the goals were revisited due to

the deterioration of transit speed and reliability. 

High violation rates have also emerged in discussions with some HOV operators as necessitating the

need for a policy shift that could enable better enforcement. One school of thought is that pricing may

help to curb violation rates, as violators could buy in to the lane, generating a revenue stream and

supporting increased infrastructure that in turn supports better enforcement activities. Infrastructure 

improvements could include improved lane configuration, implementation of enforcement technology, and 

increased presence of law enforcement. 

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Figure 3-2: Do you have plans to revisit / have you revisited the goals of your HOV system based 

on any of the following reasons? 

HOV Lane Operational Policies and Policy Changes 

There is wide variation in HOV lane operational policies across the country, which is largely dependent on 

system design and usage trends related to system goals, local politics (e.g., acceptance of toll lanes, 

carpool formation rates, air quality conformity, public support, transit ridership, legislative mandates), and

the relationship of HOV lanes to the commute patterns of the traveling public. HOV operational limitations 

and performance issues have often been addressed by policy changes including occupancy requirements 

and hours of operation. The concept of managed lanes has further evolved to include vehicle eligibility, 

pricing, and access control as a viable means to impact overall lane performance and system efficiency. 

Policy changes impacting hours of operation and occupancy requirements have been implemented and 

explored in many locations experiencing empty-lane syndrome as a means to improve utilization of the 

HOV system. Hours of operation have been reduced from 24-7 operations to weekday peak periods or 

daytime hours in some urban areas. This is typically due to political and public pressure for use of the 

lanes. In most cases, occupancy requirements have been decreased (e.g.., from 3+ to 2+ or from 4+ to 

3+) to relax carpool requirements and improve lane utilization. Increases in occupancy requirements have 

also been considered as a means to address lane overcrowding, and this has been successful in some

areas such as Houston. At the same time, studies in other urban areas indicate that increases in

occupancy requirements have resulted in sharp drops in lane usage and additional congestion in the

general-use lanes. For this reason, many areas now view pricing as a better option to manage lane

congestion.

Conversion to or from general-purpose lanes has frequently been part of the HOV conversation. Many 

regions report constant public and political pressure to convert HOV capacity to general use, despite

results indicating positive HOV performance. In Vancouver, Washington, design issues including a lack of

connections to other HOV facilities and connections to park and ride resulted in conversion of HOV lanes 

to general-purpose lanes after a pilot project even with performance results indicating positive lane

performance. “Take away” of a general-use lane for conversion to a managed lane is not a politically 

popular concept. Nevertheless, many departments of transportation (DOTs) across the country are

including this option as part of the discussion. In concert with pricing, managed lanes may help to address 

current or future transportation funding shortfalls for urban areas. 

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Access changes have been common on existing systems over the years. Access and/or egress locations 

may be added or shifted due to public support, safety concerns, or in response to changing congestion

levels that may impact lane performance. Access changes have typically been implemented in design 

situations where striping or moveable barriers can easily be shifted. 

Figure 3-3: Have any of the following policy changes been applied / are you considering any of the 

following changes to your original HOV System?

Survey results indicate that pricing is currently explored most frequently among respondents as a 

potential policy change (see Figure 3-3 above). Pricing is viewed as a potential solution for a spectrum of 

issues—potentially addressing unused HOV capacity in the peak period and the need for better lane 

management in congested conditions and providing needed revenue. Systems with a transit-oriented

focus believe pricing can help directly impact transit trip times that are potentially degraded on congested

HOV lanes. Pricing also offers a better performance management option for some regions because of the

impacts that solutions such as an occupancy requirement change alone may have on the generalpurpose lanes. Pricing is packaged with at least one additional policy change—most frequently, vehicle 

eligibility to allow SOVs into the lane. Pricing also has benefits that could potentially address HOV

enforcement concerns in areas with extremely high violation rates that impact lane performance. 

Vehicle eligibility was also identified as a frequently implemented policy change. HOV lane eligibility has 

most frequently been expanded to allow motorcycles and hybrid vehicles into the lanes. In some areas, 

lanes initially designated as bus-only or transit-only have been expanded to include HOVs. The issue of

hybrid and alternative fuel vehicle eligibility varies by state and has been handled in a variety of ways. 

Many systems permitting these vehicles did so prior to the mass market availability of hybrids. Given 

hybrid availability and rising fuel prices, allowing these vehicles has had a significant impact on HOV lane

conditions in recent years, particularly in locations where lanes are already congested in peak periods. 

Hybrids may also have a significant impact on revenue on systems that have converted or are 

considering a conversion to HOT. Pressure from politicians in some states impedes lane operators from 

excluding hybrid vehicles from managed lanes, even in congested situations. The compromise has been

to cap the numbers of hybrid vehicles eligible for lane usage through vehicle registration or permitting 

programs. For HOT lane systems, operators have issued a limited number of transponders to hybrid 

users through a lottery or registration process. HOV systems attempting to cap hybrid usage, such as in

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Virginia, initiated a date cutoff tied to vehicle registration and issue a special license plate to permitted

hybrid users.

Policy Change Motivations 

Follow-up interviews with survey respondents revealed motivations for previously implemented policy

changes on HOV lanes. These previous policy changes ranged from occupancy restrictions and hours of 

operation to the implementation of tolling for otherwise ineligible vehicles (e.g., SOVs). The original 

motivation for past policy changes varied, but a few common themes emerged from the interviews.

Empty-lane syndrome was the single most frequent motivation for conversion of HOV lanes to HOT lanes.

In these cases, the HOV lanes were underutilized, and public desire was for HOV lanes to be returned to 

general-use lanes. To retain benefits for carpoolers, while addressing the perception of underutilized HOV

lanes, the agencies proposed pricing as a means to increase vehicle throughput in both HOV and 

general-use lanes. Pricing of SOVs provides a more flexible option for managing lane volume. By varying

the SOV (“buy-in”) toll rates in the HOT lanes, an agency can attract enough vehicles to fill the lanes 

while still avoiding congestion from too much demand. A parallel motivation for shifting HOV to HOT is the 

desire for new revenue. 

Many DOTs cannot afford to adequately maintain, improve, or expand their current systems without 

additional revenue or without help from private sector resources. Public-private partnership initiatives

have emerged as a new funding mechanism for managed-lanes projects and are based upon the premise 

that there will be a return on investment for the private sector. Revenue generated from priced lanes 

makes this type of funding mechanism possible. In some states, priced lanes are currently viewed as the

only mechanism for future freeway capacity expansion, given limited resources and regional

transportation goals and policies. 

Some responding agencies have also made changes to occupancy restrictions, eligibility restrictions, and 

hours of operation. Conversion from an occupancy policy of 2+ to that of 3+ (or even 4+) is typically in

response to peak period congestion. Some agencies apply this increased restriction for the entire period

of HOV operation, while others just apply the change in the peak hour, with the original occupancy

restriction in the off-peak. Examples also exist where the responsible agency originally made the

occupancy requirement too restrictive. There are instances where 3+ or 4+ policies have been changed 

to 2+ or 3+ due to lack of use. Indeed, there are even a couple of examples of HOV 2+ lanes being

converted back to general use for the same reason. Vehicle eligibility is another change category that 

HOV operators have leveraged. In the last several years, there has been particular interest in allowing

low-emission and/or hybrid vehicles in HOV lanes, regardless of the number of persons inside. Federal 

law (SAFETEA-LU) currently allows this, and some states have taken steps to implement this policy 

change. HOV operators have also changed the hours of operation of their facilities. For those facilities 

that are not restricted all 24 hours of the day, operating hours can be changed to best serve the travel 

market. For example, peak spreading could lead to congestion in the corridor at times when the HOV lane

is open to all traffic. By expanding the hours of operation, the advantage of increased travel speeds can 

be preserved for carpoolers. 

Table 3-1 summarizes the anticipated performance impacts of potential policy changes based on the 

operating conditions in an HOV lane. 

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Table 3-1: HOV Conditions and Potential Policy Changes 

HOV Lane Condition Policy Change Anticipated Result

Occupancy policy decrease

Increased volumes in the HOV lane and shift 

from general-use lanes due to relaxed 

restrictions. 

Hours of operation change

Increased daily volumes in the HOV lane and 

shift from general-use lanes due to relaxed 

restrictions. 

Vehicle eligibility 

□ Hybrid 

□ Transit 

□ Motorcycle 

Increased volumes in the HOV lane and shift 

from general-use lanes due to relaxed 

restrictions. 

Pricing 

Increased volumes in the HOV lane and shift 

from general-use lanes, particularly during 

peak periods when SOV drivers can pay for a 

guaranteed travel time. Revenue stream

generated from paying SOV drivers. Positive 

impact on general-use lanes due to volume 

shift during peak period. 

Conversion to GP lane 

Increased lane volume due to the removal of 

lane restrictions. Decreased person and 

vehicular throughput, and degraded transit trip 

times can be anticipated for the corridor due to 

lack of demand management and lack of travel 

time incentives to carpoolers and transit users. 

Underutilized 

Access changes 

Increased volumes in the HOV lane and shift 

from the general-use lanes if access/egress 

better reflects peak period commute patterns or 

is easier for the public to understand and 

utilize. 

Occupancy policy increase

Decreased volumes in the HOV lane and shift 

to the general-use lanes due to increased 

restrictions. Potential for negative impact on 

general-use lanes if there is a sharp decrease 

in carpools meeting new requirements. 

Vehicle eligibility 

□ Hybrid 

□ Transit 

□ Motorcycle 

Decreased volumes in the HOV lane and shift 

to the general-use lanes due to increased 

restrictions. Increased restrictions on hybrid 

vehicles are most likely to impact lane

performance but can be controlled through 

registration caps and permitting. 

Congested 

Pricing 

Free-flow volumes maintained in the lane

during hours of operation due to active lane 

management, particularly during peak periods. 

Revenue stream generated from paying SOV 

drivers. Guaranteed travel times on priced 

lanes during peak periods also provides

benefits to carpoolers and transit users. 

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HOV Lane Condition Policy Change Anticipated Result

Add or convert a lane 

Increased person and vehicular throughput and 

improved travel times due to an extra lane of 

managed capacity. Potential for negative 

impact on general-use lanes if there is a lane 

takeaway. 

Pricing 

Improved monitoring on the HOV lanes due to 

enhanced infrastructure. Revenue stream

generated from paying SOV drivers can help to 

support monitoring efforts. High violation rate / 

Incorrect utilization 

Access changes 

More restrictive access will curb tendencies for 

ineligible drivers to enter the lane. Access 

changes can include separation changes (i.e., 

stripe vs. buffer vs. pylon) or ingress/egress 

location changes 

Pricing 

Free-flow volumes maintained in the lane

during hours of operation due to active lane 

management, particularly during peak periods, 

supports transit trip reliability. Revenue stream 

generated from paying SOV drivers can 

support transit operations. Guaranteed travel 

times on priced lanes during peak periods 

provide benefits to transit users and could 

increase transit ridership. 

Vehicle eligibility 

□ Hybrid 

□ Motorcycle 

Decreased volumes in the HOV lane and shift 

to the general-use lanes due to increased 

restrictions. Increased restrictions on hybrid 

vehicles are most likely to impact lane

performance but can be controlled through 

registration caps and permitting. 

Degraded transit trip 

times

Add or convert a lane 

Improved transit travel times due to an extra 

lane of managed capacity. Additional lane 

could be reserved for transit-only usage or 

transit and carpool usage for additional traveltime reliability. Potential for negative impact on 

general use lanes if there is a lane takeaway. 

Policy Implementation Success Factors 

While lane performance is a central factor in the decision for HOV policy change and the key to

understanding the system impacts of one policy over another, there are many other factors that influence

the successful implementation of a policy change. Changes such as hours of operation, vehicle eligibility, 

and occupancy may in some circumstances be policy changes within the authority of the facility operator,

or they may require legislative action, depending on the institutional arrangements and laws in a particular 

location. Authorized policy changes are of course a quicker path to implementation, as they do not require

the formal actions of elected legislators. Some agencies acknowledged preferences for not opening up

legislative issues, but rather to work with factors within their control. Opening up legislation can lead to 

unexpected outcomes and slow response to the operating issues faced. Some HOV operators have

appointed boards designated to make policy decisions regarding HOV systems. This institutional 

arrangement can facilitate the HOV policy decision-making process, particularly when multiple partnering

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agencies are involved. Along these same lines, many operators comment that specific Federal rules 

related to HOV policy changes and lane performance actually facilitate implementation at the local level. 

Some states still require enabling legislation for HOV policy changes. There are many examples of policy 

changes that have been made due to the political will of legislators or other local leaders, and there are at 

least as many that have failed due to the lack of a political champion. In particular, all HOT lane operators 

across the country indicate that political support and a political champion was a key in overcoming 

potential implementation hurdles for HOT lanes. It typically has taken years of education and persuasion 

to cultivate political leaders and agency partners to implement HOT pricing on existing HOV lanes. 

Effective interagency coordination and clear ownership of designated roles and responsibilities is another 

commonality across systems that have successfully implemented HOT lanes. Research studies and data 

that validate the need for this type of policy change are also critical tools to support these decisions. 

Transportation agencies exploring pricing have also learned that not all HOV lanes are good candidates 

to be HOT lanes. Many lanes that meet the performance “rules of thumb” for conversion are constrained 

corridors with no space for tolling systems without costly design overhauls and acquisition of additional 

rights-of-way. The HOT facilities currently in operation are regarded as “low hanging fruit” relative to other 

facilities under study for conversion. 

Recent experience has been promising. Operating agencies have made progress with the support of US 

DOT grant programs such as the Urban Partnership Agreement (UPA) and the Value Pricing Pilot 

Program (VPPP). Corridors have been carefully selected for implementation considering factors that 

promote a high likelihood for success. 

Typical success factors include favorable geometrics and access locations, reasonable potential for 

public acceptance, a political champion, clear roles and responsibilities between agencies, and strong 

interest from the transit operator. In general, agencies proposing candidate facilities for conversion 

experience 20 percent or more of unused capacity in the peak period, and have the staff and financial 

resources to plan, design, implement, and operate the HOT facility. The lack of some of these factors1

 is 

a principle reason given for abandoned efforts in the past. 

Federal assistance in rule-setting would be helpful in some areas, such as in rules and guidance for 

setting minimum occupancy and eligibility policies. For example, in conditions where occupancy policy 

must increase to 3+ to address congestion, but hybrid vehicles are still allowed in the lanes, this seems 

counterintuitive to many in the HOV/HOT community. 

 

1

 Or the need for too many design exceptions and compromises to overcome right-of-way limitations and other 

geometric design problems 

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SECTION 4: POLICY OPTIONS EVALUATION TOOL 

Purpose 

Every HOV lane is unique in its demand composition and operational characteristics. These 

characteristics are often difficult to quantify, so it is challenging for HOV operators to know exactly how 

well their HOV lanes are operating. Likewise, the impacts of any policy changes to their HOV facilities are 

also difficult to quantify, and would create additional uncertainty concerning future HOV performance. So 

before making any changes, it is critical to understand: (1) the current operating conditions of the existing 

HOV facility; (2) what impacts on the operational performance of the HOV facility can be expected with 

policy shifts; and (3) whether policy shifts will help the operator meet the goals and objectives established 

in the study region. 

Travel demand modeling is one approach commonly used to evaluate current and future conditions in 

transportation systems. These models can be used to estimate the potential impacts of policy shifts, 

including changes in HOV lane policies. However, the traditional modeling process tends to be complex 

and requires extensive time and budget to implement, rendering it ineffective for quick-response analysis. 

The Policy Options Evaluation Tool for Managed Lanes (POET-ML) was developed as one feasible 

alternative to travel demand modeling. The tool makes it possible for HOV operators to complete a 

current HOV system condition assessment, quantify the impacts of HOV lane policy shifts on operational 

performance and financial feasibility, and ultimately prioritize the most appropriate HOV policy changes, 

or combination of HOV policy changes, to best align with their system goals and performance objectives. 

This will all be accomplished through a simple user interface that does not require extensive modeling 

know-how. Users equipped with even limited input data will be able to apply what they know to get 

sketch-level planning output and suggestions for HOV policy modification. 

Specifically, POET-ML has been structured to help HOV operators answer the following questions: 

• How effective are HOV facilities in my region? How well are these lanes utilized? 

• What HOV policy changes are necessary to address locations where my HOV facility appears to 

be underutilized, or where excess capacity on the HOV facility exists during the peak period and 

off-peak period? What HOV policy changes are optional to address these concerns? 

• What HOV policy changes are necessary to address locations where my HOV facility is 

congested during the peak period? What HOV policy changes are optional to address these 

concerns? 

• What are the advantages or disadvantages associated with each HOV policy change? 

• How is HOV system performance impacted as a result of each policy change or combination of 

policy changes? 

• Will the changes in HOV policy meet the system goals and performance objectives? Which policy 

changes are recommended to meet those goals and performance objectives? 

The POET-ML framework, methodology, and illustrative results from four typical scenarios (Scenario 1: 

HOV & GP Lanes Both Under Capacity; Scenario 2: HOV Lane Under Capacity & GP Lanes Congested; 

and Scenario 3: HOV Lane & GP Lanes Over Capacity [Increased Restrictions]; and Scenario 4: HOV 

Lane & GP Lanes Over Capacity [Additional Capacity]) are provided next. The POET-ML tool itself is 

provided as a separate deliverable.

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Framework, Methodology, and Illustrative Results 

Figure 4-1 illustrates the analytical process used in POET-ML. 

Figure 4-1: POET-ML Framework

Step 1: Operational Assessment of Existing HOV Facility

The initial step in the model process is an assessment of the operational effectiveness of the existing

HOV facility. This assessment considers both physical and operational characteristics including number of 

lanes, length, separation, eligibility, and demand, among others. 

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In this step, the user can select a specific HOV facility from the FHWA Highway HOV Facility Inventory 

database that includes information on HOV policy details and physical characteristics. The user is then

required to enter the number of HOV lanes and GP lanes in each direction during peak hour operations 

as well as the corresponding volumes in these lanes (records highlighted in red). Other information, such

as public transportation vehicles (no. of buses per hour); percentage of motorcycles; percentage of taxi

and percentage of low emission and/or energy efficient vehicles, is optional. Once valid values are

entered for these items, the user can continue with the analysis. It is also possible to store a specific 

profile for future use by modifying the text for one or more of the input data field records. 

Table 4-1 outlines the set of information to be populated either from the FHWA Highway HOV Facility 

Inventory database or by the user. The data was grouped into four major categories. General

information, physical characteristics, and HOV policies should be readily available to nearly any user 

familiar with the HOV system under consideration. However, travel demand and operational performance 

could be more difficult to obtain. 

Table 4-1: User Inputs

 Data 

Category Data Requirement Data Sources Requirement 

• State / Province Required

• City / County Required

• Urban Area Required

• Road name Required

General 

Information 

• Segment (from/to) 

FHWA 

Highway HOV 

Facility 

Inventory Required

• Route Miles 

FHWA 

Highway HOV 

Facility 

Inventory 

Required

• No of HOV Lanes Per Direction User Input Required

• No of General Purpose Lanes Per 

Direction User Input Required

• Type Optional 

• Intermediate Access Optional 

Physical 

Characteristics

• Separation 

FHWA 

Highway HOV 

Facility 

Inventory Optional 

• Eligibility HOV Required

• Eligibility Toll Optional 

• Eligibility Motorcycle Optional 

• Eligibility Taxi Optional 

• Eligibility Special Fuel Optional 

• Eligibility Others Optional 

HOV Policies 

• Hours of Operation 

FHWA 

Highway HOV 

Facility 

Inventory 

Optional 

• HOV Lane Volume (Peak Hour) in 

Peak Direction* Required

• GP Lane Volume (Peak Hour) in 

Peak Direction* Required

• Public transportation vehicles (no. 

of buses per hour) Optional

• Percentage Motorcycles Optional

• Percentage Taxi Optional

Travel 

Demand and 

Operational 

Performance 

• Percentage Low emission and/or 

energy efficient vehicles 

User Input 

Optional

* Volumes represent demand for the corridor by lane type. 

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Figure 4-2: Model Input Page

REQUIRED 

USER INPUTS 

User input, to be input to the model using the interface shown in Figure 4-2, will supply the information 

necessary to assign the HOV facility to one of two categories based on the established performance 

thresholds, such as volume-to-capacity ratios or service flow rate (pc/h/ln). These categories describe the 

general performance of the facility in terms of utilization. During step 2 of this process, the user will be 

presented with a set of policy adjustments based on the specific category to which the facility is assigned. 

Table 4-2 outlines the two categories and corresponding performance thresholds by default. 

Table 4-2: HOV Facility Performance Thresholds

Categories Volume-to-Capacity 

Ratios

Service Flow Rate 

(pc/h/ln) 

• HOV facility that has excess 

capacity during both peak and offpeak periods; 

 Peak Hour V/C Ratio 

<0.75 

Peak Hour Service Flow 

Rate < 1650 pc/h/ln 

• HOV facility that is congested 

during the peak period and has 

excess capacity during the offpeak period. 

Peak Hour V/C Ratio 

>=0.75 

Peak Hour Service Flow 

Rate >= 1650 pc/h/ln 

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It is important to note that the default threshold values of V/C ratio (0.75) and service flow rate (1650 

pc/h/ln) were established based on aggregated national survey results, and they are consistent with the

assumptions in FHWA’s Spreadsheet Model for Induced Travel Estimation - Managed Lanes (SMITEML). The default values of V/C ratio and service flow rate are stored in the POET-ML parameters page

and remain interactive and transparent to the user. Users are allowed to adjust these values to reflect the 

unique characteristics of facilities in their region. To review and/or modify the default model parameters 

navigate to the Potential Impacts page and select “Adjust Parameters”. 

The precision of the analysis will depend on the availability of data from the user, and the quality of the 

final model output depends entirely on the user’s ability to supply as much needed information as 

possible. 

Example:

The example corridor is I-85 in Atlanta, GA from I-75 north to SR316. This 24 mile facility has 

a single HOV lane in each direction with HOV2+ occupancy policy. Key information was 

loaded from the HOV data base. User input included:

No. of HOV Lanes Per Direction = 1 

No. of General Lanes Per Direction = 5 

HOV Lane Volume (Peak Hour) in Peak Direction = 2,200 

GP Lane Volume (Peak Hour) in Peak Direction = 11,250 

Step 2: Identification of the required and/or optional HOV policy changes 

A set of applicable policy adjustments are introduced in step 2 of the model process, based on the 

assessment from step 1. If it is determined that the HOV facility has excess capacity in both the peak and 

off-peak periods, the user will be shown a number of policy change options related to vehicle occupancy, 

vehicle eligibility, and pricing. In order to fill unused HOV capacity, and avoid empty lane syndrome, the

user could choose to lower the occupancy restrictions (e.g. from HOV3+ to HOV2+) or to allow additional

free vehicles (e.g. public transportation vehicles, taxis, motorcycles, hybrid vehicles, etc.). Additionally, 

the user could convert the lanes from HOV to high-occupancy toll (HOT) lanes, and sell excess capacity

to users not permitted in the lanes but who would be willing to pay for the travel time savings these lanes 

provide. These policy changes could also be bundled together in some combination that both achieves

the utilization targets and meets the goals of the region. Table 4-3 shows the options to be presented to

the user. 

The same set of policy change options applies for HOV facilities determined to be congested during peak 

periods. However, the potential adjustments will be more restrictive, rather than less restrictive, as was 

the case for the excess-capacity scenario. For example, one option to address congested HOV lanes is 

to increase the occupancy requirements (e.g. from HOV2+ to HOV3+). Likewise, non-carpools that are 

currently eligible to use the HOV lanes could be prohibited (e.g. disallow motorcycles, transit vehicles, 

etc.). Pricing of non-eligible vehicles can also be implemented on congested HOV lanes, but it must be

bundled with some other policy shift. Once demand in these lanes is brought down below capacity 

through more restrictive policies, any remaining capacity could be sold to ineligible vehicles (i.e. those not

meeting the current occupancy/eligibility policy) that are willing to pay for access. In addition to policy 

change options related to vehicle occupancy, vehicle eligibility, and pricing, the user can also explore the

impacts of adding an additional managed lane. This option is only available for HOV facilities that are

congested during peak period. This could either be an additional lane in each direction, or an additional 

reversible lane, depending on the facility. By adding additional capacity, it provides increased flexibility for 

HOV operators and eliminates the need for immediate occupancy policy changes. Table 4-4 shows the

options for the congested peak period condition. 

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- December 2008 

If HOV demand is deemed to be on target during peak periods (i.e. neither underutilized nor congested), 

there are still opportunities for policy adjustment. Future demand may eventually lead to congestion in 

lanes that are operating well today, and proactive steps could ensure efficient operation for years to 

come. Pricing is always an option that provides flexibility for HOV operators to manage demand in these 

lanes in order to achieve more efficient use. Occupancy and eligibility policy changes alone, offer only 

discrete solutions that may tip the utilization balance too far in one direction. 

f HOV demand is deemed to be on target during peak periods (i.e. neither underutilized nor congested), 

there are still opportunities for policy adjustment. Future demand may eventually lead to congestion in 

lanes that are operating well today, and proactive steps could ensure efficient operation for years to 

come. Pricing is always an option that provides flexibility for HOV operators to manage demand in these 

lanes in order to achieve more efficient use. Occupancy and eligibility policy changes alone, offer only 

discrete solutions that may tip the utilization balance too far in one direction. 

 

Example:

Based on the volumes in the corridor, both the HOV and general purpose lanes operate at 

undesirable levels, LOS E and F for the HOV and GP lanes respectively. 

Mobility Impacts in HOV Lanes and General Purpose Lanes During Peak Hours 

With Existing HOV Policy Mobility Impacts HOV Lane GP Lane 

Peak Hour V/C 1.00 1.02

Peak Hour Speed (mph) 34.2 33.1

Level of Service E F

Corridor Travel Time (minutes) - Congested Condition 41.9 43.3

Total Vehicle Travel Delays (hours) 728 3,983

Total Vehicle Delay * VOT of $/hr 18,200 99,575

 

Mobility Impacts in HOV Lanes and General Purpose Lanes Daily 

With Existing HOV Policy Mobility Impacts HOV Lane GP Lane 

Daily V/C 0.75 0.77

Daily Speed (mph) 47.2 46.0

Daily Level of Service C D

Corridor Travel Time (minutes) - Congested Condition 30.4 31.2

Total Vehicle Travel Delays (hours) 3,614 20,520

Total Vehicle Delay * VOT of $/hr 90,350 513,000

Travel Efficiency (Speed * Volume) 1,235,939 6,209,440

Potential policy adjustments include: 

1. Increase vehicle occupancy from HOV2+ to HOV3+ or HOV 4+ 

2. Further restrict vehicle eligibility such as transit, motorcycles, taxis or low emission 

vehicles. In this example, motorcycles and transit vehicles are the only vehicle 

types with eligibility. 

3. Allow pricing of non-eligible vehicles (this requires an initial policy shift to free-up 

capacity to sell, increased occupancy or additional capacity for example). 

4. Add an additional managed lane in each direction. 

 
FHWA Task 4 

HOV Lane Performance Project 

Table 4-3: Potential Policy Adjustments for Facilities with Excess Capacity Condition (Empty Lane Sy

Operating Element Direction of 

Change 

Details Policy Ch

Option

Vehicle Occupancy (HOV) Decrease 

By relaxing the vehicle occupancy restrictions, more vehicles could gain access to HOV lanes, filling unused capacity in the currently underutilized lanes. 

Vehicle Occupa(HOV) Public transporvehicles (no. of hour) Motorcycles Taxi 

Free Vehicle Eligibility 

Less Restriction By allowing vehicles that don't meet the existing 

vehicle eligibility policy (e.g. low emission and energy-efficient vehicles) to use the HOV lanes, more vehicles could gain access to these lanes, filling unused capacity. 

Low emission aenergy efficient 

Pricing 

Allow Paying 

Vehicles 

For the existing HOV lanes which are underutilized, allowing vehicles that don't meet passenger occupancy or vehicle eligibility requirements to gain access to HOV lanes by paying a toll provides the opportunity to fill unused capacity and also provides transportation choice for those willing to pay. By pricing those previously ineligible vehicles, new revenue is generated that could, if authorized, be utilized for transportation improvements. 

Paying vehicles 

 -23- 
FHWA 

HOV Lan

Task 4 

e Performance Project 

 -24- 

Table 4-4: Potential Policy Adjustments for Facilities with Congested Peak Period Conditions

Operating Element Direction of 

Change 

Details Policy Ch

Option

Vehicle Occupancy (HOV) Increase 

By increasing the vehicle occupancy requirement, some currently eligible HOVs are diverted from the lanes, providing additional capacity in currently overutilized HOV lanes. 

Vehicle Occupa(HOV) Public transporvehicles (no. of hour) Motorcycles Taxi 

Free Vehicle Eligibility 

More Restrictions 

By disallowing some currently eligible vehicles, additional capacity is freed up in the overutilized HOV lanes. 

Low emission aenergy efficient 

Pricing 

Allow Paying 

Vehicles 

Pricing needs to be bundled with a vehicle occupancy change, (free) vehicle eligibility change, and/or capacity change for the facility that is overutilized. By pricing those previously ineligible vehicles, new revenue is generated that, if authorized, could be utilized for transportation improvements. 

Paying vehicles 

Additional Capacity Add a Managed Lane 

Building additional capacity provides increased flexibility for HOV operators facing peak period congestion. Additional capacity eliminates the need for immediate policy changes. 

Capacity 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Step 3: Evaluation of Potential Impacts 

The third step in the process is to assess the impacts of the HOV lane policy change or combination of 

policy changes that were selected in step 2. The tool will track four key measures of effectiveness: travel 

demand impacts, mobility impacts, environmental impacts, and financial feasibility. 

Travel Demand Impacts 

Both vehicle and person travel demand will be examined over daily and peak hour periods in the 

HOV/HOT and general-purpose (GP) lanes. Travel will be broken down into carpools, transit, 

motorcycles, special fuel vehicles, taxis, and paying vehicles. At a minimum, the user will be 

required to supply information on peak hour vehicle trips for each vehicle type under the current 

HOV policies. Relationships coded into the tool will be used to calculate peak hour person trips 

and daily vehicle and person trips. 

Travel demand impact calculations will depend heavily on which of the two conditions (excess 

capacity or congested) applies to the facility under evaluation. If pricing is selected as a policy 

change, the level of travel demand in priced lanes will be maintained at Level of Service C during 

the peak hour, by default, i.e., about 75% of absolute capacity. Paying vehicle volumes in priced 

lanes during the peak hour are estimated to be equal to the spare vehicle capacity that would be 

available on the lanes at a Level of Service C. The balance of the volume is occupied by nonpaying vehicles. 

A number of combinations exist between existing conditions and subsequent policy adjustments. 

The algorithms in place to determine final volumes for both HOV/HOT lanes and general purpose 

(GP) lanes are different based on the combination under consideration. Following are four 

potential scenarios, meant to outline the different calculation processes executed by POET-ML. 

Each scenario description includes a table with example output data and a figure showing general 

travel conditions in the corridor. Following these scenarios is a detailed description of the 

calculations for mobility and environmental impacts, along with financial feasibility. 

Scenario 1: HOV & GP Lanes Both Under Capacity 

Many corridors with HOV lanes are uncongested in peak periods. Under these conditions, no 

changes are required to bring HOV operating speeds back to acceptable levels. However, the 

HOV operator may be interested in seeing the impact of implementing pricing, or of allowing 

additional vehicles into the HOV lanes through occupancy or eligibility changes. Figure 4-3 

illustrates the potential impact of allowing priced vehicles into the HOV lanes. The colored arrows 

represent the flow conditions for each lane in the corridor. Table 4-5 shows an example 

calculation for this scenario. 

Of the 1,100 peak hour HOV trips in the existing condition, 1,004 of them are carpools. The rest 

are other eligible vehicles. These other vehicles generally make up a small proportion of total 

HOV demand, and therefore changes to eligibility restrictions could have little direct impact on 

HOV and GP lane performance. 

Initially, this uncongested corridor experiences LOS C conditions in the GP lanes and LOS A/B 

conditions in the HOV lane. Allowing priced vehicles in the HOV lane will attract additional users 

because of the time savings relative to the GP lanes. POET-ML pulls these users from two 

different places: the GP lanes and parallel facilities. The percent split from these sources 

depends on the conditions in the GP lanes. As the V/C ratio in the GP lanes rises, the 

contribution of vehicles from these lanes to the HOV/HOT lane also rises. When GP conditions 

are near LOS A/B, a larger portion of vehicles are diverted from parallel facilities to the HOV/HOT 

-25- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

lane. The final volumes in the HOT lane under this condition are no higher than the maximum

LOS C volume defined in the Tool. Nor are they larger than 1⁄4 the total corridor volume (1⁄4 

because the facility has 4 total lanes, with one HOV lane). This is to ensure that HOT operating

speeds do not fall below GP speeds, which is a possible, but unlikely scenario. For these

reasons, revenue is likely to be minimal under this condition. Obviously, few motorists would be

willing to pay a toll to use the HOT lane when only minimal time savings can be realized. 

Indeed, Table 4-5 shows just 300 paying vehicles after the policy change, bringing the peak hour 

total in the HOV/HOT lane to 1,400. Volumes decrease from a total of 4,500 on the GP lanes to

4,380. With a per lane capacity of 2,200 vehicles per hour, the GP lanes have a similar V/C ratio

to that of the HOV/HOT lane, which is the reason for the low demand from paying vehicles in that

lane. 

Table 4-5: Scenario 1 Lane Condition Data 

Existing HOV Policy With Policy Changes 

Travel Demand Impacts – Scenario 1 HOV (1) 

Lane 

GP (3) 

Lane 

HOV (1) 

Lane 

GP (3) 

Lane 

Total Peak Hour Vehicle Trips (with PCE factor) 1,100 4,500 1,400 4,380

Peak Hour Carpools (Free) 1,004 N/A 1,004 N/A

Peak Hour Others (Transit) 10 N/A 10 N/A 

Peak Hour Motorcycle 17 N/A 17 N/A

Peak Hour Taxi 17 N/A 17 N/A

Peak Hour Special Fuel 33 N/A 33 N/A 

Peak Hour Tolling 0 N/A 300 N/A 

Figure 4-3: Scenario 1 Lane Condition Diagrams 

 A/B C D E/F

Level of Service (LOS)

G

P Lane

G

P Lane

G

P Lane

H

O

V Lane

G

P Lane

G

P Lane

G

P Lane

H

O

T Lane

 Initial Condition Condition after Change

-26- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

 Scenario 2: HOV Lane Under Capacity & GP Lanes Congested 

Another common scenario involves congested GP lanes adjacent to an HOV facility that operates 

well below capacity. Again, the operator is not required to make policy changes in order to 

maintain an acceptable LOS in the HOV lane, but there may be interest in achieving greater 

utilization in this lane. Options for increasing HOV volumes include relaxing occupancy and 

eligibility restrictions in the lanes, as well as allowing previously ineligible vehicles (e.g. singleoccupant vehicles) to pay a toll in order to use the lane. These options would have different 

impacts on lane volume, however, and caution needs to be observed to avoid creating congested 

HOV conditions. For example, lowering the occupancy restriction from 3+ to 2+, if applicable, 

could potentially allow too many vehicles into the HOV lane, degrading performance below 

acceptable levels. 

In this example, a congested corridor has an underutilized HOV lane. This condition is commonly 

referred to as “empty lane syndrome”, and is one key motivator for HOV policy change. Allowing 

priced vehicles access to the HOV lane can lead to improvements in the GP lanes and better use 

of the HOV lane. One likely outcome of this change can be seen in Figure 4-4. Here, LOS 

improves from ‘E/F’ to ‘D’ on the GP lanes, while LOS degrades slightly on the HOV/HOT lane 

from ‘A/B’ to ’C’. In POET-ML, most of the priced vehicles in the HOT lanes come from the GP 

lanes under these conditions, with a small contribution from parallel facilities. As a result, total 

corridor throughput increases slightly under this scenario. As noted previously, vehicle 

contribution from these two sources is determined based on a sliding scale with a 70/30 split 

between parallel facilities and GP lanes when the GP lanes operate at LOS A. This split changes 

to 60/40 under LOS B, 50/50 under LOS C, 40/60 under LOS D, and 30/70 under LOS E/F 

conditions. This distribution is included in the parameters page, and can be modified by the user. 

HOT lane volumes are capped at the LOS C capacity, which is accomplished in practice through 

demand-responsive, variable tolling. If pricing is not a viable alternative, an HOV operator could 

still achieve greater corridor throughput by increasing the types of eligible vehicles in the HOV 

lane. Allowing hybrids or special fuel vehicles, taxis, or additional transit vehicles can provide a 

degree of relief to the GP lanes while increasing utilization of the HOV lane. However, as 

discussed previously, relaxing eligibility restrictions may not impact many vehicles, and therefore 

conditions may not change much in the corridor. 

Table 4-6 shows example output from this scenario. Here, HOV volume is brought to capacity 

after pricing is allowed, and GP lane conditions improve with decreases of more than 100 

vehicles per lane. Again, total corridor throughput increases over the existing case. Pricing 

allows for more efficient movement in these 4 lanes. 

Table 4-6: Scenario 2 Lane Condition Data 

Existing HOV Policy With Policy Changes 

Travel Demand Impacts – Scenario 2 HOV (1) 

Lane 

GP (3) 

Lane 

HOV (1) 

Lane 

GP (3) 

Lane 

Total Peak Hour Vehicle Trips (with PCE factor) 1,100 6,700 1,650 6,315 

Peak Hour Carpools (Free) 1,004 N/A 1,004 N/A 

Peak Hour Others (Transit) 10 N/A 10 N/A 

Peak Hour Motorcycle 17 N/A 17 N/A 

Peak Hour Taxi 17 N/A 17 N/A 

Peak Hour Special Fuel 33 N/A 33 N/A 

Peak Hour Tolling 0 N/A 550 N/A 

-27- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Figure 4-4: Scenario 2 Lane Condition Diagrams 

HOV Lane

GP Lane

GP LaneGP Lane

 A/B C D E/F

Level of Service (LOS) HOT Lane

GP Lane

GP LaneGP Lane

 Initial Condition Condition after Change 

Scenario 3: HOV Lane & GP Lanes Over Capacity (Increased Restrictions) 

Some HOV facilities are congested during peak periods and require policy adjustment in order to 

maintain federally mandated performance standards. Low cost strategies for decreasing HOV 

lane volume include increasing occupancy restrictions and implementing more exclusive eligibility 

criteria. However, efforts to divert vehicles from the HOV lanes can lead to increased congestion 

on GP lanes. And if HOV lane rules are made too restrictive, traffic could fall well below LOS C 

conditions, leading to empty lane syndrome. For example, in many urban areas, the vast majority 

of HOVs have just 2 occupants, with only a small percentage of 3+ occupant vehicles. If the HOV 

operator increases the occupancy restriction from 2+ to 3+, many of the vehicles in the lane will 

no longer be eligible, and will be diverted to the GP lanes or parallel facilities. 

POET-ML takes into account the overcapacity scenario described above. Once it is determined 

that the HOV lane is congested in peak periods, the user is presented with a list of potential policy 

changes designed to achieve improved HOV operating conditions. The greatest impact usually 

comes from increased occupancy restrictions. Figure 4-5 shows an example of the impact of first 

increasing this restriction from 2+ to 3+, followed by allowing priced vehicles in the lane. 

The first selection shifts a large number of vehicles from the HOV lane to the GP lanes. Of 

course, the number of vehicles diverted will vary by facility, according to the regionally-specific 

HOV mix (i.e. the relative number of HOV2, HOV3, HOV 4+, etc.). This split is coded as a 

parameter in the Tool, and it can be updated by the user as desired. If the user changes only the 

occupancy restriction, total corridor volume will remain constant, and GP lane conditions will likely 

become even more congested. In addition, it is possible that the HOV lane may exhibit LOS A/B 

conditions, which is suboptimal utilization. If the user follows this selection by allowing pricing in 

the HOV lane, however, vehicles return to the lane and fill the unused capacity. POET-ML pulls 

most of the priced vehicles from the GP lanes, and a smaller portion from parallel facilities. This 

split is also coded as a parameter in the Tool, and if the user desires to vary the source of priced 

vehicles, he or she has that flexibility. Once both decisions are executed, conditions are likely to 

appear as they do on the right of Figure 4-5. 

-28- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Table 4-7 shows the extent to which the GP lanes become more congested in this scenario. Of 

course, the HOV lane is maintained at the LOS C capacity, and most of these vehicles are tolled. 

HOV3+ vehicles, along with other eligible free vehicles, comprise the balance of the lane volume. 

The HOV2 vehicles, which were pushed to the GP lanes in response to the occupancy policy 

change, are responsible for the increased GP lane congestion. 

Table 4-7: Scenario 3 Lane Condition Data 

Existing HOV Policy With Policy Changes 

Travel Demand Impacts – Scenario 3 HOV (1) 

Lane 

GP (3) 

Lane 

HOV (1) 

Lane 

GP (3) 

Lane 

Total Peak Hour Vehicle Trips (with PCE factor) 2,200 6,700 1,650 7,621

Peak Hour Carpools (Free) 2,104 N/A 316 N/A 

Peak Hour Others (Transit) 10 N/A 10 N/A 

Peak Hour Motorcycle 17 N/A 17 N/A

Peak Hour Taxi 17 N/A 17 N/A

Peak Hour Special Fuel 33 N/A 33 N/A 

Peak Hour Tolling 0 N/A 1,238 N/A 

Figure 4-5: Scenario 3 Lane Condition Diagrams 

G

P Lane

G

P Lane

G

P Lane

H

O

V Lane

 A/B C D E/F

Level of Service (LOS)

G

P Lane

G

P Lane

G

P Lane

H

O

T Lane

 Initial Condition Condition after Changes 

-29- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Scenario 4: HOV Lane & GP Lanes Over Capacity (Additional Capacity) 

Another option for addressing a corridor with congested HOV and GP lanes is to add HOV/HOT 

capacity. In locations where available right of way affords such an investment, this option can 

provide a high degree of flexibility for HOV operators. Additional HOV capacity allows greater 

opportunities for efficient corridor flow and can eliminate the need for occupancy and/or eligibility 

policy change. In the scenario highlighted in Figure 4-5, the user has opted to add HOV capacity 

and implement tolling in these lanes. In doing so, corridor conditions are improved for both the 

managed and GP lanes. In addition, total corridor volume increased, which means the facility can 

serve more vehicles, more efficiently than before. And all of this is possible while maintaining 

occupancy restrictions of 2+. This last point is important, because raising occupancy restrictions 

can be controversial. Those that have formed 2 person carpools to use the HOV lanes will likely 

object to any change in policy that forces them out of the lanes. Additional capacity can help 

avoid this situation. 

In the scenario highlighted in Figure 4-6, the user has chosen to address corridor congestion by 

maintaining the existing HOV policy, adding a lane of HOV/HOT capacity, and implementing 

pricing on both lanes. POET-ML is equipped to respond to each of these decisions and to 

calculate the final conditions on the managed and GP lanes. The additional HOV lane doubles 

the capacity for qualifying vehicles. These vehicles are spread evenly over the two lanes, which 

likely eliminates peak period congestion. Allowing priced vehicles fills unused capacity in these 

lanes while helping to improve conditions in the GP lanes. Again, the majority of paying vehicles 

are taken from the GP lanes, with a smaller percentage diverted from parallel facilities. 

The number of free vehicles in the HOV lanes remains the same both before and after the 

capacity addition, as shown in Table 4-8. This allows for a 1,100 paying vehicles to enter the 

HOV/HOT lanes, bringing both lanes to their LOS C capacity. Since many of those paying 

vehicles come from the GP lanes, total GP volume decreases from 6,700 to 5,930, resulting in 

improved LOS on these lanes as well. 

Table 4-8: Scenario 4 Lane Condition Data 

Existing HOV Policy With Policy Changes 

Travel Demand Impacts – Scenario 4 HOV (1) 

Lane 

GP (3) 

Lane 

HOV (2) 

Lanes 

GP (3) 

Lane 

Total Peak Hour Vehicle Trips (with PCE factor) 2,200 6,700 3,300 5,930 

Peak Hour Carpools (Free) 2,104 N/A 2,104 N/A 

Peak Hour Others (Transit) 10 N/A 10 N/A 

Peak Hour Motorcycle 17 N/A 17 N/A 

Peak Hour Taxi 17 N/A 17 N/A 

Peak Hour Special Fuel 33 N/A 33 N/A 

Peak Hour Tolling 0 N/A 1,100 N/A 

-30- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Figure 4-6: Scenario 4 Lane Condition Diagrams 

HOV Lane

GP Lane

GP LaneGP Lane

 A/B C D E/F

Level of Service (LOS) HOT Lane

HOT Lane

GP Lane

GP LaneGP Lane

 Initial Condition Condition after Changes 

Additionally, POET-ML analyzes the peak hour person trips based on occupancy rate for different vehicle 

types. It also analyzes the total daily vehicle trips and total daily person trips based on Peak Hour 

vehicle/person trips and daily to Peak Hour Conversion factor. Table 4-9 outlines those travel demand 

impacts and its corresponding calculation methodology. Table 4-10 fills in these formulas, under the 

existing conditions, with values from the example cited earlier. 

Table 4-9: Daily Conversion Formulas 

With Existing HOV 

Policy 

Travel Demand With Selected Policy Changes Impacts 

 HOV Lane GP Lane HOV Lane GP Lane 

Total Peak Hour 

Person Trips

HOV Lane: 

Persons Vehicles) Paying Fuel Special

 Buses (Free) (Carpools Hour Peak Taxi s Motocycle

+

+ + + +

GP Lane: 

Occupancy Auto Average* Trips Vehicle Lane GP Hour Peak Rate

Peak Hour Carpool 

Persons (Free) Occupancy Carpool* Trips Vehicles (Free) Carpools Hour Peak Rate

Peak Hour Others 

(Transit) Occupancy Bus* Trips Vehicles Bus Hour Peak Rate

Peak Hour Motorcycle Hour Peak Occupancy Auto Average* Trips Motocycle Rate

Peak Hour Taxi Occupancy Auto Average* Trips Taxi Hour Peak Rate

Peak Hour Special Fuel Hour Peak Occupancy Auto Average*Trips Vehicle Fuel Special Rate

-31- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Peak Hour Tolling Peak Hour Tolling Trips * Average Auto Occupancy Rate

Daily 

Total Daily Vehicle 

Trips 

HOV Lane: 

Daily (Carpools (Free) + Buses + Others + Paying Vehicles)

GP Lane: 

Daily to Peak Hour Conversion Factor

Peak Hour GP LaneVehicle Trips* 

Daily Carpools (Free) in 

HOV Lane* Peak HourCarpools(Free)* Daily to Peak HourConversionFactor

Daily Buses in HOV

Lane* Peak Hour Buses * Daily to Peak Hour Conversion Factor

Daily Others in HOV 

Lane* Daily to Peak Hour Conversion Factor

Peak Hour (Motocycles + Taxi + Special Fuel Vehicles)* 

Daily Paying Vehicles

in HOV Lane* Daily to Peak Hour Conversion Factor

Peak Hour Paying Vehicles(Free)* 

Total Daily Person 

Trips 

HOV Lane: 

Daily (Carpools (Free) + Buses + Others + Paying Vehicles)

GP Lane: 

Daily to Peak Hour Conversion Factor

Peak Hour GP LaneVehicle Trips* 

Daily Carpool Persons 

(Free) in HOV Lane* Daily Carpools Persons (Free) * Daily to Peak Hour Conversion Factor

Daily Bus Passengers 

in HOV Lane* Daily Buses Passengers * Daily to Peak Hour Conversion Factor

Daily Other Persons in 

HOV Lane* Daily to Peak Hour Conversion Factor

Peak Hour (Motocycles Persons + Taxi Persons + Special Fuel Persons)

Daily Paying Persons in 

HOV Lane* Daily to Peak Hour Conversion Factor

Peak Hour Paying Persons(Free)* 

*Only applies to HOV Lane. 

-32- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Table 4-10: Daily Conversion Calculations 

With Existing HOV 

Policy

Travel Demand With Selected Policy Changes Impacts 

 HOV Lane GP Lane HOV Lane GP Lane 

Total Peak Hour 

Person Trips

HOV Lane: 

=4,665 + 200 + 0 + 36 + 36 + 0 = 4,938

GP Lane: 

=11,250 * 1.1 = 12,375

Peak Hour Carpool 

Persons (Free) =2,121 * 2.2 = 4,665

Peak Hour Others 

(Transit) =10 * 20 = 200

Peak Hour Motorcycle =0 * 1.1 = 0

Peak Hour Taxi =17 * 2.1 = 36

Peak Hour Special Fuel =33 * 1.1 = 36

Peak Hour Tolling =0

Daily 

Total Daily Vehicle 

Trips 

HOV Lane: 

=25,452 + 120 + 600 + 0 = 26,172

GP Lane: 

=11,250 * 12 = 135,000

Daily Carpools (Free) in 

HOV Lane* =2,121 * 12 = 25,452 

Daily Buses in HOV

Lane* =10 * 12 = 120

Daily Others in HOV 

Lane* =(0 + 17 + 33) * 12 = 600

Daily Paying Vehicles

in HOV Lane* =0

Total Daily Person 

Trips 

HOV Lane: 

=55,980 + 2,400 + 864 + 0 = 59,244 

GP Lane: 

=12,375 * 12 = 148,500

Daily Carpool Persons 

(Free) in HOV Lane* =4,665 * 12 = 55,980

Daily Bus Passengers 

in HOV Lane* =200 * 12 = 2,400

Daily Other Persons in 

HOV Lane* =(0 + 36 + 36) * 12 = 864

Daily Paying Persons in 

HOV Lane* =0

-33- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Mobility Impacts 

The travel demand impacts will then be used to determine the facility operating conditions, 

including the volume-to-capacity ratio, operating speed, level of service, facility travel time, total 

vehicle travel delay, etc. Again, these impacts will be examined over daily and peak hour periods 

for both the HOV and GP lanes. 

To calculate each of the mobility impacts, a number of assumptions are embedded into the 

calculations of these impacts. Examples of values the user may wish to update include Hourly 

Freeway Capacity per Lane (vph), Free Flow Speed (mph), the values for “alpha” and “beta" used 

in the Bureau of Public Roads equation for computing congested Peak Hour and Daily Travel 

Speeds, V/C thresholds for Level of Service, etc. All these assumptions are stored in the POETML Parameters Page. The user will have explicit access to change these assumptions if desired 

to better fit the characteristics of specific facilities and areas. 

The calculations for mobility impacts are built with flexibility in mind, allowing the user to 

customize the assumptions to a specific region, if the data supports it, and if there is a desire for 

greater precision in the results. If not, the user can work with the set of assumptions that 

emerged out of the model calibration effort, which will be based on nationwide averages. 

Table 4-11 outlines the information to be included for these mobility impacts and the detailed 

calculation methodology of those mobility impacts. Table 4-12 fills in these formulas, under the 

existing conditions, with values from the example cited earlier. 

Table 4-11: Matrix of Mobility Impacts

With Existing HOV 

Policy 

With Selected Policy 

Mobility Impacts Changes HOV Lane GP Lane HOV Lane GP Lane 

Peak Hour 

Peak Hour V/C Hourly *Lanesof# Freeway Capacity (vph) Lane Per

PCE) (With Trips Vehicle Hour Peak Total

Peak Hour Travel Speed 

(mph) ( )beta alpha1

SpeedFlowFree

+ C/VHourPeak

Peak Hour Level of Service 

(LOS) 

Peak Hour V/C<=0.3, LOS = A

0.3< Peak Hour V/C<=0.5, LOS = B

0.5< Peak Hour V/C<=0.75, LOS = C

0.75< Peak Hour V/C<=0.9, LOS = D 

0.9< Peak Hour V/C<=1.0, LOS = E

Peak Hour V/C>1.0, LOS = F

Peak Hour Corridor Travel 

Time (minutes) - Congested 

Condition )mph(SpeedHourPeak

60*MilesRoute

Peak Hour Total Vehicle 

Travel Delays (hours) 

Trips Vehicle Hour Peak Total*

)

)mph(SpeedFlowFree

MilesRoute

)mph(SpeedHourPeak

MilesRoute

( −

-34- December 2008 
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HOV Lane Performance Project Draft Final Report 

Peak Hour Total Vehicle 

Travel Delay * Cost of 

Vehicle Delay ($/hr) ($/Hr) VOT* Delay Travel Vehicle Total Hour Peak

Peak Hour Travel Efficiency 

(Speed * Volume) Hour Peak Total * SpeedHour Peak Trips Vehicle

Daily 

Daily V/C Daily *Lanesof# Freeway Capacity (vph) Lane Per

PCE) (With Trips Vehicle Daily Total

Daily Travel Speed (mph) ( )beta alpha1

SpeedFlowFree

+ C/VDaily

Daily Level of Service 

Daily V/C<=0.3, LOS = A 

0.3< Daily V/C <=0.5, LOS = B 

0.5< Daily V/C <=0.75, LOS = C

0.75< Daily V/C <=0.9, LOS = D 

0.9< Daily V/C <=1.0, LOS = E 

Daily V/C >1.0, LOS = F

Daily Corridor Travel Time 

(minutes) - Congested 

Condition )mph(SpeedDaily

60*MilesRoute

Daily Total Vehicle Travel 

Delays (hours) 

Daily Total* Trips Vehicle

)

)mph(SpeedFlowFree

MilesRoute

)mph(SpeedDaily

MilesRoute

( −

Daily Total Vehicle Travel 

Delay * Cost of Vehicle 

Delay ($/hr) Daily Total ($/Hr) VOT* Delay Travel Vehicle

Daily Travel Efficiency 

(Speed * Volume) Daily Total * Speed TravelDaily Trips Vehicle

-35- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Table 4-12: Mobility Impacts Calculations 

With Existing HOV 

Policy

With Selected Policy

Mobility Changes Impacts 

 HOV Lane GP Lane HOV Lane GP Lane 

Peak Hour

Peak Hour V/C =2,200 / (1 * 2,200) = 1.0 

Peak Hour Travel Speed 

(mph) =65 / (1+0.9 * (1)^3) = 34.2

Peak Hour Level of Service

(LOS) 0.9< Peak Hour V/C<=1.0, LOS = E

Peak Hour Corridor Travel

Time (minutes) - Congested 

Condition 

=(23.9 * 60) / 34.2 = 41.9

Peak Hour Total Vehicle 

Travel Delays (hours) (23.9 / 34.2 – 23.9 / 65) * 2200 = 728

Peak Hour Total Vehicle 

Travel Delay * Cost of 

Vehicle Delay ($/hr) 

=728 * 25 = 18,200

Peak Hour Travel Efficiency 

(Speed * Volume) =34.2 * 2,200 = 75,240

Daily 

Daily V/C =26,160 / (1 * 35,000) = 0.75

Daily Travel Speed (mph) =65 / (1 + 0.9 * (0.75)^3) = 47.2

Daily Level of Service 0.5< Daily V/C <=0.75, LOS = C 

Daily Corridor Travel Time 

(minutes) - Congested 

Condition 

=(23.9 * 60) / 47.2 = 30.4

Daily Total Vehicle Travel 

Delays (hours) (23.9 / 47.2 – 23.9 / 65) * 26,160 = 3,614

Daily Total Vehicle Travel 

Delay * Cost of Vehicle 

Delay ($/hr) 

=3,614 * 25 = 90,350

Daily Travel Efficiency 

(Speed * Volume) =47.2 * 26,160 = 1,234,752

-36- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Environmental Impacts 

POET-ML will use the traffic volume estimates and mobility impact estimates to evaluate the 

environmental effects of the HOV facility under consideration. Two key environmental indicators 

will be examined, including air quality performance and carbon dioxide. 

The quantity of gasoline conserved can directly relate to reduced vehicular emissions. Gasoline 

savings were based on numbers derived using Texas Transportation Institute assumptions of 

0.68 gallons of fuel per hour of delay. The evaluation will consider changes in total vehicle delay 

as a result of the policy adjustment package selected by the user and estimate the fuel-based 

emissions based on gas savings and estimated vehicular emission rates per gallon. Due to the 

difficulty in determining advancement in emissions technology, the values used in POET-ML 

reflect modern day estimated emission rates, as illustrated in Table 4-13. 

Table 4-13: Matrix of Environmental Impacts2

Air Quality - Pollutant 

Passenger Car 

Average 

Emissions 

CO (kg/gallon) 14.44 

NOx (kg/gallon) 1.27 

VOC (kg/gallon) 1.91 

Carbon Dioxide (kg/gallon) 8.79 

For example, if the model results predict a reduction in total vehicle travel delay as a result of a 

conversion form HOV lanes to HOT lanes, POET-ML will model changes in air quality and carbon 

dioxide emissions based the above average rates. The user will be able to see the impact of any 

delay reduction in environmental terms. 

Table 4-14 outlines the information to be included for the environmental impacts and the 

calculation methodology of these two performance measures. Table 4-15 fills in these formulas, 

under the existing conditions, with values from the example cited earlier. 

 

2

 Source: Environmental Protection Agency 

-37- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Table 4-14: Environmental Impacts Formulas 

With Existing HOV 

Policy

With Selected Policy

Changes Environmental 

Impacts 

 HOV Lane GP Lane HOV Lane GP Lane 

Peak Hour

Air Quality (kg) 

VOC ) X * PassengerCar Aversage Emssion of (CO NO

Peak Hour TotalVehicleTravel Delay * Gallons of Fuel /Hour

+ +

Carbon Dioxide 

(kg) * Passenger Car Aversage Emssion of Carbon Dioxide

Peak Hour Total VehicleTravel Delay * Gallons of Fuel /Hour

Daily 

Air Quality (kg) 

VOC ) X * Passenger Car Aversage Emssion of (CO NO

Daily Total VehicleTravel Delay * Gallons of Fuel /Hour

+ +

Carbon Dioxide 

(kg) * Passenger Car Aversage Emssion of Carbon Dioxide

Daily Total Vehicle Travel Delay * Gallons of Fuel /Hour

Table 4-15: Environmental Impacts Calculations 

With Existing HOV 

Policy

With Selected Policy

Changes Environmental 

Impacts 

 HOV Lane GP Lane HOV Lane GP Lane 

Peak Hour

Air Quality (kg) =728 * 0.68 * (14.44 + 1.27 + 1.91) = 8,723

Carbon Dioxide 

(kg) =728 * 0.68 * 8.79 = 4,351

Daily 

Air Quality (kg) =3,614 * 0.68 * (14.44 + 1.27 + 1.91) = 43,302

Carbon Dioxide 

(kg) =3,614 * 0.68 * 8.79 = 21,602

Again, the user will have access to adjust all the estimated emission rates for CO (kg/gallon), 

NOx (kg/gallon), VOC (kg/gallon) and Carbon Dioxide (kg/gallon) in the POET-ML Parameter 

page if desired. 

-38- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Financial Feasibility 

The final measure of effectiveness is financial feasibility. The set of policy adjustments includes 

pricing of existing HOV lanes, and if pricing is selected, it will trigger additional analysis in the 

model. Again, the user will have access to assumptions behind these calculations, including 

value of time estimates, weekend/weekday revenue ratios, and per-transaction tolling operation 

costs. The model incorporates national averages for these inputs and uses the results from the 

mobility impact analysis to perform this financial evaluation. 

Output for this step includes the number of tolled vehicles, daily and annual revenue, and annual 

toll operation costs. Also bundled with this output is a set of transportation benefits calculated in 

monetary terms. These are presented as travel time and fuel savings as well as daily user 

benefits resulting from policy changes implemented on the HOV facility. Specific measures of 

financial feasibility and its corresponding calculation methodology are listed in Table 4-16. Table 

4-17 presents example calculations assuming that occupancy restrictions were changed from 2+ 

to 3+ in the example cited previously.

Table 4-16: Matrix of Financial Feasibility Output 

Financial With Selected Policy Changes 

Feasibility 

 HOV Lane GP Lane 

Toll Revenue and Toll O&M Cost 

(Only apply to Scenario with Policy Change of Pricing on Existing HOV Lanes) 

Number of 

vehicles paying a 

toll in peak hours Impacts) Demand Travel (from

Trips Vehicle Tolling Hour Peak

Number of 

vehicles paying a 

toll in other Daily 

Periods 

Impacts) Demand Travel (from

Daily Trips Vehicle Tolling

Total Daily 

Revenue 

60/ Time of Value Minimum*

Daily Total Time TravelDaily HOT * Trips Vehicle Tolling Savings)

Time Travel Hour Peak HOT * Trips Vehicle Tolling Hour Peak (Total Savings

+

Total Daily 

Revenue per Mile Daily Total MileRoute / Revenue

Number of 

Working Days per 

Year 

Page) Parameter (from 250

Gross Annual 

Revenue 

Weekday and Revneue Weekend of Ratio Revenue

Daily Total *Year) Per Days Working of Number -(365* Revenue

Daily Total Year Per Days Working of Number* Revenue +

Annual Toll 

Operation Costs 

Transactio Per Cost Operation Toll Annual* n)

Weekday and Revneue Weekend of Ratio* Revenue))

Year) Per Days Working of Number -(365 Year Per Days Working of ((Number

Daily Trips Vehicle Tolling Hour (Peak * Trips) Vehicle Tolling

+

+

Travel Benefits 

(Categorized by Lane Type: HOV Lanes and GP Lanes when compared to Existing HOV Policy Scenario) 

-39- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

Daily User 

Mobility Benefits 

(Travel Time 

Savings * VOT of 

$/hr) Policy (With ($/Hr) VOT* Policy) Exisiting v.s Change

Delay Travel Vehicle TotalDaily on Difference

Policy (With ($/Hr) VOT* Policy) Exisiting v.s Change

Delay Travel Vehicle Total Hour Peak on Difference

+

Fuel Cost 

Savings (Gallons) 

Policy (With /Hour Fuel of Gallons* Policy) Exisiting v.s Change

Delay Travel Vehicle TotalDaily on Difference

Policy (With /Hour Fuel of Gallons* Policy) Exisiting v.s Change

Delay Travel Vehicle Total Hour Peak on Difference

+

Note: 

HOT Peak Hour Travel Time Saving = GP Lane Peak Hour Travel Time - HOT Lane Peak Hour Travel Time 

HOT Daily Travel Time Saving = GP Lane Daily Travel Time - HOT Lane Daily Travel Time 

Table 4-17: Financial Feasibility Calculations 

Financial With Selected Policy Changes 

Feasibility 

 HOV Lane GP Lane 

Toll Revenue and Toll O&M Cost 

(Only apply to Scenario with Policy Change of Pricing on Existing HOV Lanes) 

Number of 

vehicles paying a 

toll in peak hours 

=1,252

Number of 

vehicles paying a 

toll in other Daily 

Periods 

=15,029

Total Daily 

Revenue =1,241 * (49-30.4) + 15,029 * (33.6-25.5) * 25/60 = 60,341

Total Daily 

Revenue per Mile =60,341 / 23.9 = 2,525

Number of 

Working Days per 

Year 

250

Gross Annual 

Revenue =60,341 * 250 + 60,341 * (365-250) * 0.25 = 16,820,054

Annual Toll 

Operation Costs =(1,252 + 15,029) * (250 + (365-250) * .25) * .15) = 610,557

Travel Benefits 

(Categorized by Lane Type: HOV Lanes and GP Lanes when compared to Existing HOV Policy Scenario) 

Daily User 

Mobility Benefits 

(Travel Time 

Savings * VOT of 

$/hr) 

=(18,200 – 5,750) + (90,350 – 28,275) = 74,525

Fuel Cost 

Savings (Gallons) =(728 - 230) + (3,614 – 1,131) = 2,027

-40- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

• Step 4: Evaluation of Goals and Objectives 

The analysis does not end with step 3. Recognizing that regional goals largely dictate transportation 

policy decisions, POET-ML includes an evaluation of selected policy adjustments in order to understand 

their ability to address common goals. The tool will employ a simple matrix that relates policy changes 

with common goal statements. This matrix will be populated with values that reflect the relative strength 

of each policy in addressing each goal. Example goals include the following: 

o Protect Mobility 

o Maximize person throughput 

o Provide an option for travel time savings and trip reliability 

o Encourage carpooling in peak periods 

o Support transit service and reliability 

o Manage congestion by improving system efficiency 

o Improve air quality 

o Provide a Financially Viable System 

The user will then be able to refine the selected policy adjustment package based on this evaluation and 

return to the quantitative steps in the tool to re-evaluate this selection. In this way, the user will be able to 

strike an appropriate balance between quantitative and qualitative policy acceptability. 

-41- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

SECTION 5: CONCLUSIONS 

This study examined the performance of HOV lanes based on the goals and objectives under which those 

HOV lanes were designed to operate and the factors that can best contribute to the success of HOV 

lanes, through targeted and focused outreach to HOV operators. An HOV Lane Compendium was 

developed that documented the basic characteristics of current and proposed High-Occupancy Vehicle 

(HOV) lanes throughout the United States. A survey and follow-up interviews with HOV facility owners 

was conducted in order to reveal why HOV lanes are successful, why some owners are considering policy 

changes, and what are the future expectations of HOV lanes. Then, a Policy Options Evaluation Tool for 

Managed Lanes (POET-ML) was developed to quantify the impacts of pricing and other policy shifts on 

the operational performance of the nation’s HOV lanes. 

The results of the HOV operator survey and interviews revealed similar operational challenges and 

common categories of performance characteristics across HOV systems nationally. Localized habits and 

usage trends produce significant differences in outcome expectations for policy changes. In general, 

there does not appear to be a “one size fits all” understanding of the approaches to HOV policy change 

for improved operations. There are, however, distinct characteristics and lessons learned that increase 

the chances for successful policy implementation under certain conditions. Identifying an appropriate 

policy change, or set of policy changes, is just an initial step in addressing HOV lane performance 

challenges. Bringing these changes to bear is the next challenge. The following is a summary of 

conclusions on factors and policy change, as identified by HOV operators: 

• Areas with general public familiarity and acceptance of tolled facilities (i.e., areas where toll roads are 

currently in operation) are more likely to buy into new pricing concepts. 

• Federal rules can provide support to defuse politically charged policy issues that, while they may 

improve level-of-service, are unpopular in the region. 

• Even slight operational changes to hours of operation can have significant impact on general-use 

lanes due to commute patterns and congestion levels prior to and immediately following peak-period 

HOV operation. A thorough analysis of operations implications is very important before deciding on a 

shift of HOV policy. 

• Because an HOV occupancy policy increase can cause sharp decreases in eligible carpool formation, 

and because it can negatively impact general-use lane congestion during peak periods, pricing is 

currently viewed as a more promising lane management approach. But pricing approaches require 

significant facility/technology and time investments for implementation. 

• Complementary policy changes, such as occupancy changes or access changes, almost always go 

along with conversion to HOT facilities, to make the conversion work as intended. Such changes may 

be implemented incrementally. 

• Pricing implementation is increasingly viewed by the HOV/HOT community as feasible in congested 

areas only with the addition of new lanes and transit infrastructure. In some regions, this may be the 

only approach by which “new capacity” may be financed and built. 

• Pricing implementation has often not been successful without a political champion and clearly defined 

relationships and responsibilities between agency partners. 

• Close coordination with FHWA on design exceptions and other geometric concerns will be paramount 

in future pricing implementation projects in urban areas with limited right-of-way and capacity-building 

options. 

The Policy Options Evaluation Tool for Managed Lanes (POET-ML) was developed to enable HOV 

operators and policy-makers the ability to observe how HOV policy changes will impact the performance 

of HOV facilities, employing both quantitative analyses and qualitative reality checks. This tool was 

designed to be flexible enough to allow a user with little information to gain a comprehensive 

understanding of the current operational effectiveness of a specific HOV facility and to evaluate the 

-42- December 2008 
FHWA Task 4 – Final Documentation 

HOV Lane Performance Project Draft Final Report 

impacts of potential policy changes. HOV operators with more extensive input data, and a motivation for 

more customized results, are granted access to adjust a number of model assumptions in order to

account for regional variation. 

Every HOV lane is unique in its demand composition and operations. Policy changes will leave a unique

footprint with respect to operational performance and financial feasibility. It is important to recognize that 

the impacts of such policy changes will vary significantly depending on localized conditions including but 

not limited to travel times, trip purposes, and driver willingness to pay. In the documentation of POET-ML, 

we organized the multitude of potential inputs and outcomes into a manageable number of typical

scenarios (Scenario 1: HOV & GP Lanes Both Under Capacity; Scenario 2: HOV Lane Under Capacity & 

GP Lanes Congested; and Scenario 3: HOV Lane & GP Lanes Over Capacity [Increased Restrictions]; 

and Scenario 4: HOV Lane & GP Lanes Over Capacity [Additional Capacity]). Each scenario varies with

respect to mobility impacts, environmental impacts, and financial feasibility. POET-ML provides high-level

impacts of proposed HOV policy adjustments – more detailed analysis is recommended prior to

implementation of any policy changes identified in the tool. 

-43- December 2008 
Contact Information 

For additional information on this report, contact: 

Federal Highway Administration 

Ms. Jessie Yung 

(202) 366-4672 

jessie.yung@fhwa.dot.gov 

John Wiegmann 

Booz Allen Hamilton Inc. 

8283 Greensboro Drive 

McLean, Virginia 22102

703-902-3151 

wiegmann_john@bah.com

Mark Chang

Booz Allen Hamilton Inc. 

8283 Greensboro Drive 

McLean, Virginia 22102

415-263-3752 

chang_mark@bah.com

Andrew Smith 

HNTB Corporation 

3715 Northside Pkwy NW 

Atlanta, GA 30327 

404-946-5708 

asmith@HNTB.com

 

Claudia Bilotto 

HNTB Corporation 

3715 Northside Pkwy NW 

Atlanta, GA 30327 

404-946-5747 

cbilotto@HNTB.com

Federal Highway Administration 

1200 New Jersey Avenue SE 

Washington, DC 20590 

December 2008 

Publication # FHWA-HOP-09-029