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1 FHWA Work Zone Management Facts & Statistics: http://www.ops.fhwa.dot.gov/wz/resources/facts_stats.htm

2 FHWA Work Zone Safety and Mobility Rule: http://www.ops.fhwa.dot.gov/wz/resources/final_rule.htm

WHAT IS THE CONNECTION BETWEEN ATDM AND WORK 

ZONE MANAGEMENT?

This brief is intended to discuss the connection between ATDM and work zone 

mobility and safety including strategies and tactics for successful implementations and 

associated benefits and lessons learned. Many strategies that agencies commonly 

deploy during construction activities could be enhanced by embracing ATDM 

concepts to become more dynamic and actively managed to further improve work 

zone mobility and safety. The information presented in this brief focuses on ATDM 

with respect to work zone management, supporting transportation agencies in the 

beginning phases of developing a Transportation Management Plan (TMP) that 

includes a temporary traffic control plan, traffic operations component, and public 

information and outreach component, all relevant to ATDM.

MITIGATING WORK ZONE IMPACTS THROUGH ATDM

Aging roadway infrastructure and increasing highway congestion means more road 

work by States, localities, and utilities resulting in greater work zone impacts. As the 

number of work zones increase so do mobility and safety issues. In fact, 131 work 

zone-related injuries are noted to occur every day while one work zone-related fatality 

occurs every 15 hours.

(1) It is estimated that work zone related travel delay accounts 

for up to 24 percent of all non-recurring delay.(1) In response to these concerns, 

agencies are beginning to shift from the notion that congestion is an “inevitable 

consequence” of work zones to more proactive management approaches of 

implementing ATDM strategies to improve mobility and safety in and around work 

zones.

Agencies can consider ATDM strategies during the planning and operational phases 

of a work zone to influence travel demand:

 Planning for Construction. Agencies may take an active work zone management 

approach in their TMP – including targets, and performance metrics in line with 

regional objectives and the Work Zone Safety and Mobility Rule (23 CFR 630 

Subpart J)(2), which requires use of work zone safety and operational data to 

improve projects. ATDM technologies enable agencies to generate and use data 

to satisfy the Rule.

 Managing Demand during Construction. Agencies utilize active demand 

management strategies to encourage reduced travel along a work zone route in a 

number of ways, including: incentivizing travelers to use different routes, 

encouraging alternate modes, and adding capacity to public transit.

 Using Active Traffic Management for Work Zone Operations. Many permanent and temporary Intelligent 

Transportation Systems (ITS) can mitigate potential mobility and safety impacts caused by work zones.

What is Active 

Transportation and Demand 

Management (ATDM)?

ATDM is the dynamic 

management, control, and 

influence of travel demand, traffic 

demand, and traffic flow of 

transportation facilities. Through 

the use of available tools and 

assets, traffic flow is managed 

and traveler behavior is 

influenced in real-time to achieve 

operational objectives, such as 

preventing or delaying 

breakdown conditions, improving 

safety, promoting sustainable 

travel modes, reducing 

emissions, or maximizing system 

efficiency. Under an ATDM 

approach the transportation 

system is continuously 

monitored. Using archived data 

and or/predictive methods, 

actions are performed in realtime to achieve or maintain 

system performance. 

Active 

Management
IMPLEMENTING ATDM STRATEGIES IN WORK ZONES

A variety of ATDM approaches have been and are currently being used to mitigate work zone impacts across the country.

While numerous strategies are available, the examples below describe successful deployments of ATDM strategies that 

enhanced mobility and safety in and around work zones:

Queue Warning Systems. Static signing is placed in advance of a work 

zone to alert drivers of changing conditions, and may include a word 

message to watch for slow or stopped traffic ahead. However, agencies 

may opt for a more dynamic approach by deploying a queue warning 

system. These systems generally use sensors to detect slow traffic in 

advance of a work zone and post a message to a portable changeable 

message signs (PCMS) to increase the awareness of approaching drivers, 

thereby improving safety. As an example, the Texas DOT uses sensors on 

I-35 to detect the formation of queues upstream of work zones, and warn 

drivers downstream of slowed or stopped traffic using PCMS. Some 

systems may display a simple “slow traffic ahead” message based on realtime conditions, while others provide a more specific message to indicate 

the distance to the queue or the real-time, slower vehicle speeds occurring ahead through the work zone. Benefits of a 

queue warning system in Illinois included significantly reduced speed variance, reduced vehicle conflicts, and 14 percent 

reduction of queuing crashes, despite increases in both lane closures and vehicle exposure.

Dynamic Lane Merge Systems. Early and late dynamic lane merge 

strategies are sometimes deployed prior to a work zone involving a 

lane reduction. Static signing may encourage drivers to either merge 

“early” in advance of the lane closure to potentially reduce forced 

merges, rear-end crashes, or work zone encroachment, or “late” 

closer to the closure to increase capacity during congested 

conditions. Both of these approaches can improve safety, however 

the late merge is less appropriate during periods of low congestion.

However, a dynamic system with a series of PCMS and sensors can 

be activated to provide different messages to drivers depending on 

the real-time congestion conditions to improve capacity and traffic 

throughput, as well as safety as they advise drivers of the appropriate 

location to merge prior to the work zone. Dynamic lane merge 

systems in Michigan reduced forced and dangerous merges by factors of seven and three, respectively, and increased 

average travel speeds from 40 mph to 46 mph, improving both safety and mobility. Dynamic lane merge systems have

also been used in Maryland, Minnesota, and Florida to enhance work zone safety and operations. 

Real-Time Traveler Information. Agencies can leverage a variety of 

technologies to disseminate real-time traveler information in various ways. 

Permanent or temporary sensors or detectors, private sector probe data, 

and Bluetooth data are used by agencies to determine real-time travel 

conditions through work zones. Information can be posted in real-time on 

PCMS to alert drivers enroute about work zone conditions. Many agencies 

also disseminate information via mobile applications, and some have 

partnered with private sector providers to reach more drivers and exchange

information about real-time conditions. Agencies may post delay 

information so that drivers approaching the work zone can choose to divert 

to an alternate route. As an agency progresses toward more active 

management capabilities, PCMS may be used to recommend specific 

Portable queue detection and warning 

system upstream of a work zone in Texas.

Dynamic Late Merge system in a Minnesota

work zone. 

Comparative travel time displays in a 

Michigan work zone.
alternate routes during congested periods, or provide a travel time comparison between the route under construction and 

an alternate route to reduce delays, traffic, emissions, and the number and severity of incidents. The Michigan DOT 

monitored and posted the travel times for I-75 and I-96 on static signage with dynamic elements during a major 

construction project, as shown here. Real-time traveler information improved mobility in Utah by routinely diverting 20 

percent of vehicles from a route under construction, with diversion rates of up to 50 percent at times. Pre-trip real-time 

traveler information via websites or social media can also encourage travelers to change mode, route, or trip time. 

Variable Speed Limit (VSL) Systems. Some agencies lower the posted 

speed limit when a work zone is in place based on whether or not 

workers are present. Agencies can more actively manage work zones by

adding sensors and signs through the work zone to have a more dynamic

VSL system based on real-time conditions. Advisory or enforceable 

variable speeds can help traffic flow through a work zone at more uniform 

speeds reflecting current conditions. A truly dynamic system can result in 

less stop-and-go traffic, reduce the potential for incidents, improve safety, 

and increase throughput. The Utah DOT uses portable trailers with 

mounted VSL signs, shown here, that are easily set up in work zones for 

both single-day maintenance projects and longer-duration work zones, 

and have resulted in greater speed compliance compared with static 

signing, reduced average speed, and reduced speed variation. VSL systems have also been used in Michigan, Virginia, 

and Washington State to improve work zone mobility. 

USING PERMANENT ATDM INFRASTRUCTURE TO 

SUPPORT MAJOR WORK ZONES

Aside from temporary ATDM strategies that remain in use only 

until the work zone ends, permanent ATDM infrastructure may 

also be leveraged for work zones. For instance, major work 

zone activities in Washington State were an impetus for 

deploying lane control signing with VSLs; lane control signs 

were deployed on northbound I-5 as a construction mitigation 

strategy for the Alaska Way Viaduct tunnel replacement project. 

These signs provide traveler information and VSLs for 

congestion and incident conditions, as well as work zone 

activities. The Nevada DOT is taking a similar approach, 

deploying permanent lane control signing upstream of a major 

work zone on I-15 in Las Vegas to display regulatory VSLs, 

which will remain in use following construction. Installing ATDM devices in the field at the same time as other construction 

activities on the corridor will minimize disruption to traffic and reduces the cost of the deployment, which could expedite 

installation.

BENEFITS OF ATDM IN WORK ZONES

Safety. ATDM can help minimize work zone impacts on both traveler and worker safety. Credible warnings of the 

presence of unexpected queues, notification of travel times to reduce driver stress, credible warnings of construction 

vehicle access and egress, automatic adjustment of the posted work zone speed limit to current conditions, automated 

enforcement of traffic laws, and quicker identification of incidents within work zones are examples of how ATDM in work 

zones can improve safety. An incident management system for a New Mexico work zone more quickly identified incidents 

for quicker response, reducing average incident clearance time by 20 minutes and reducing the frequency of secondary 

crashes. Automated speed enforcement in Maryland work zones resulted in a 54 percent reduction of vehicles exceeding 

the posted speed limit by 10 mph or more, as well as reduced speed disparity and more uniform flow.

Example of a portable regulatory variable 

speed limit sign used in a Utah work zone.

Lane control signs with variable speed limits were

deployed near Seattle as a construction mitigation 

strategy.
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3 FHWA’s Work Zone ITS Implementation Guide: http://www.ops.fhwa.dot.gov/publications/fhwahop14008/ 

4 FHWA Work Zone Management Program, ITS & Technology: http://www.ops.fhwa.dot.gov/wz/its/

FHWA-HOP-16-015

May 2016

Mobility. Reduced travel time delay is a primary benefit of many work zone ATDM applications. Travelers making 

adjustments to their route, departure time, or mode choices based on provided information, or the use of alternate traffic 

management practices (e.g., dynamic lane merging, VSL systems) can reduce delay. These adjustments benefit not only 

those travelers who made changes to their trips, but others who continued to travel through the work zone. Mobility 

benefits will be especially high on facilities that serve a large amount of commercial vehicle traffic, as the value of 

commercial vehicle travel time is very high. During the Woodrow Wilson Bridge project in Virginia, Washington D.C. and 

Maryland, incentives made 20 percent of commuters more likely to use alternatives, according to a follow-up survey, 

which improved work zone mobility with fewer vehicles. Additionally, encouraging mode shift with increased transit 

services can result in fewer vehicles traveling through the work zone, and improve mobility.

Additional Benefits. Include the promotion of sustainable travel modes, reduced emissions, maximization of system 

efficiency, improved customer satisfaction, and improved work zone productivity that results in a shorter project duration. 

Benefits of specific strategies are further detailed in FHWA’s Work Zone ITS Implementation Guide (3) and various case 

studies (4).

WORK ZONE CONSIDERATIONS 

Whether or not ATDM strategies are deployed in a work zone depends on a variety of factors. Primarily, the impact and 

duration of a work zone will determine whether the cost for an ATDM deployment outweighs the potential benefits, 

particularly for a shorter duration project. For instance, the costs for mobilizing and validating a large-scale temporary 

system will be relatively high for a shorter-duration project. However, a limited installation of additional sensors in the field 

or purchasing private-sector third-party data can augment and leverage existing permanent ITS infrastructure, personnel, 

or TMC resources, and may result in more viable option for deploying ATDM in a work zone. In addition, costs could be 

lower if an agency decides to purchase a system for repeated use in other work zone applications, or implements ATDM 

on a permanent basis for general incident and congestion management purposes. Traditional and social media can be 

leveraged to encourage people to cancel or modify their trips by making travelers aware of road work impacts. 

HOW CAN I FIND OUT MORE?

The ATDM Program is intended to support agencies and regions 

considering moving towards an active management approach. 

Through workshops, tools, guidance documents, resources, and peer 

exchanges, the program can assist with the technical support needed 

to implement ATDM. Importantly, ATDM is not an exclusive program 

restricted to specific agencies. Every agency that is considering 

moving towards active and dynamic capabilities can benefit from the 

ATDM program’s efforts.

The FHWA’s ATDM Website has additional information on ATDM 

concepts and tactics, current research, future events, and available resources, including resources to help agencies 

prioritize potential ATDM deployments: http://ops.fhwa.dot.gov/atdm/about/program.htm. For information on innovative 

work zone strategies and technologies visit FHWA’s Smarter Work Zones website: https://www.workzonesafety.org/swz/.

For More Information:

Jim Hunt James Colyar Greg Jones

Jim.Hunt@dot.gov James.Colyar@dot.gov GregM.Jones@dot.gov

(717) 221-4422 (360) 753-9408 (404) 562-3906

ATDM Informational Briefs

This informational brief is one in a suite of 

outreach materials. Other available briefs 

include:

 ATDM Program Overview 

 ATDM Program Brief: ATM 

 ATDM Program Brief: ADM 

 ATDM Program Brief: APM 

 ATDM Program Brief: Data Needs for ATDM

 International Influence on ATDM in the US