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 real-time to achieve or 

maintain system performance. This brief focuses on the active 

traffic management component of ATDM. 

Active management of transportation and demand can include 

multiple approaches spanning demand management, traffic 

management, parking management, and efficient utilization 

of other transportation modes and assets. Some example 

approaches are included in the table. Those highlighted in 

yellow are the focus of this brief.

Active Transportation 

and Demand Management

U.S. Department of Transportation

Federal Highway Administration

Monitor System

D

ynamic Actions

Evaluate & Recommend

Assess System

Performance

Implement

Dynamic Actions

ATDM

ATDM Program Brief: Active Traffic Management

Active Demand Management Active Traffic Management Active Parking Management

Dynamic Ridesharing Dynamic Lane Use/Shoulder Control Dynamically Priced Parking

On-Demand Transit Dynamic Speed Limits Dynamic Parking Reservation

Dynamic Pricing Queue Warning Dynamic Way-Finding

Predictive Traveler Information Adaptive Ramp Metering Dynamic Parking Capacity

What is Active Traffic Management?

Active traffic management (ATM) is the ability to dynamically 

manage recurrent and non-recurrent congestion based on 

prevailing and predicted traffic conditions. Focusing on trip 

reliability, it maximizes the effectiveness and efficiency of 

the facility. ATM approaches seek to increase throughput 

and safety through the use of integrated systems with new 

technology, including the automation of dynamic deployment 

to optimize performance quickly and without delay that occurs 

when operators must deploy operational strategies manually. 

In addition to the approaches listed in the table, ATM includes 

dynamic routing, dynamic junction control, adaptive signal 

control, and transit signal priority. These approaches can be 

described thus:

•	 Dynamic lane use/shoulder control: the dynamic 

opening of a shoulder lane to traffic or dynamic closure of 

travel lanes on a temporary basis in response to increasing 

congestion or incidents.

•	 Dynamic speed limits: the dynamic change in speed 

limits based on road, traffic, and weather conditions.

•	 Queue warning: the dynamic display of warning signs to 

alert drivers that congestion and queues are ahead.

•	 Adaptive ramp metering: the dynamic adjustment of 

traffic signals at ramp entrances to proactively manage 

vehicle flow from local-access roads.

•	 Dynamic rerouting: the dynamic provision of alternate 

route information in response to increasing congestion at 

bottlenecks/incidents.

•	 Dynamic junction control: the provision of lane access 

based on highway traffic present and merging/diverging 

traffic to give priority to the facility higher volume to 

minimize the impact of the merging/diverging movement.

•	 Adaptive traffic signal control: the optimization of signal 

timing plans based on prevailing conditions to increase 

throughput along an arterial.
Fundamental concepts of ATM are active management of 

the capacity and the direct interaction with the driver to 

encourage them to make tactical decisions in vehicle or driver 

performance (e.g., stopping, slowing down, changing lanes). 

The idea is not to simply react to changing conditions but to 

anticipate them and actively manage the system prior to their 

occurrence. All agencies and entities operating transportation 

systems can advance towards a more active management 

philosophy by making changes that move operations along 

the active management continuum. An example of temporary 

shoulder use being applied along the active management 

continuum shown in Figure 1.

At the lowest level in the continuum, agencies are mostly 

engaged in monitoring their existing lanes and infrastructure 

with the shoulders not being used as travel lanes. As agencies 

move up in the continuum, they could adjust supply on the 

facility by using shoulders as lanes during peak hours. This 

level can include such strategies as hard shoulder running, 

lane control, and improved ramp metering. Further along the 

active continuum, agencies can open or close shoulder lanes 

based on demand and can include strategies such as local 

adaptive ramp metering, responsive lane control, and shoulder 

use due to an incident or planned special event. The final level 

in the active management continuum includes 24/7 shoulder 

operations using current and predictive levels of traffic and 

incidents. To reach the highest level of active management, 

an agency needs a combination of technologies, resources, 

policies, procedures, and public acceptance. Furthermore, 

an agency may need to work through several iterations along 

the continuum before reaching the highest level. A similar 

continuum can be mapped for each of the strategies under 

ATM. Furthermore, ATM strategies are often complementary 

and can be more effective when combined to meet multiple 

objectives at the same time.

What are the key concepts of ATM?

ATDM Program Brief: Active Traffic Management

Figure 2. Active Management Continuum.

1 - Manage Flow by Time of Day

Monitor and Manage Existing Lanes

È

2 - Adjust Supply by Time of Day

Temporary Shoulder Use during Peak Hours

3 - Adjust Supply Based on Demand

È

Responsive Shoulder Use Based on Current Demand

4 - Fully Dynamic Operations

È

24/7 Operations of Shoulder Using 

Current/Predicted Levels of Traffic and Incidents

Figure 1. Minneapolis I-94 Westbound Active Traffic Management – 

Source: Texas A&M Transportation Institute.

Figure 3. Priced Dynamic Shoulder Lane (PDSL) on the Minnesota interstate – Source: Texas A&M Transportation Institute.
ATDM Program Brief: Active Traffic Management

U.S. Examples of ATM

Figure 4 shows some of the locations across the United 

States which have implemented some form of ATM on their 

transportation system. The table on the following page 

highlights some key ATM projects either in operation or under 

development. As shown, the various approaches to ATM have 

been implemented to dynamically manage lane use, speed 

limits, and ramp access. 

Agencies can realize numerous benefits with active traffic 

management. General operational benefits include: 

•	 A decrease in primary incidents by alerting drivers to

congested conditions and promoting more uniform 

speeds;

•	 A decrease in secondary incidents by alerting drivers

to the presence of queues or incidents and proactively 

managing traffic in and around incidents;

•	 Increased throughput by reducing the delay associated

with the number of primary and secondary incidents 

reducing speed differential in traffic flow, and reducing the 

shockwave effects of excessive breaking.

•	 Increased overall capacity by adding shoulder use during

congested periods when it is needed most;

•	 Overall improvement in speed uniformity during congested

periods; and

•	 Increased trip reliability by increasing capacity and

throughput and reducing incident delay and improving 

vehicle throughput.

Figure 4. Sample of Current ATM Deployments in the United States.
ATDM Project Informational Briefs

This informational brief is one of the ATDM briefs in the 

Program category of the FHWA ATDM Briefs Series. 

ATDM briefs are or will be available in the categories of: 

•	 ATDM Program Yellow

•	 ATDM Planning Purple

•	 ATDM Analysis Orange

Bob Sheehan

Robert.Sheehan@dot.gov

(202) 366-6817

Jim Hunt

Jim.Hunt@dot.gov

(717) 221-4422

James Colyar

James.Colyar@dot.gov

(360) 753-9408

Greg Jones

GregM.Jones@dot.gov

(404) 562-3906

For more information:

FHWA-HOP-13-003

OCTOBER 2012

•	 ATDM Design Green

•	 ATDM Operations Red

ATDM Program Brief: Active Traffic Management

Specific identifiers that may indicate whether or not ATM 

strategies should be implemented and produce desirable 

benefits include:

•	 High traffic volumes;

•	 Changes in prevailing conditions;

•	 A high prevalence of crashes;

•	 Capacity bottlenecks;

•	 Adverse weather;

•	 Adverse environmental impacts;

•	 Variability in trip reliability;

•	 Construction impacts;

•	 Financial constraints and priorities; and,

•	 Limitation in capacity expansion.

Figure 5. Seattle I-5 Northbound Active Traffic Management 

(termed Smarter Highways by WSDOT) – Source: Texas A&M 

Transportation Institute.

Location(s) ATM Strategy(ies) Active Technologies

Mobile County, AL / Flagstaff, AZ / 

Portland, ME / Truckee River, NV /

Pittsburgh, PA / Knoxville, TN / 

Cheyenne, WY

weather-driven dynamic speed limits traffic management center (TMC) control, 

variable speed limit signs, atmospheric 

sensors, visibility sensors, pavement 

conditions sensors, dynamic message 

signs

Los Angeles, CA / Minneapolis, MN / 

Portland, OR / Houston, TX

adaptive ramp metering roadway sensors, ramp meter signals, 

TMC algorithms, TMC control

Minneapolis, MN dynamic lane use control, dynamic speed 

limits, queue warning, adaptive ramp 

metering

roadway sensors, lane control/dynamic 

speed limit signals, dynamic message 

signs, TMC algorithms and control

Seattle, WA dynamic lane use control, dynamic speed 

limits, queue warning, adaptive ramp 

metering

roadway sensors, lane control/dynamic 

speed limit signals, dynamic message 

signs, TMC algorithms and control

Northern Virginia dynamic lane use control, dynamic speed 

limits, queue warning, dynamic shoulder 

lanes

roadway sensors, lane control signs, 

dynamic speed limit signals, dynamic 

message signs, TMC algorithms and 

control

Various adaptive traffic signal control microwave sensors, CCTV, tag readers,

central control

Los Angeles dynamic junction control dynamic lane assignment signs, 

illuminated pavement markers