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TRANSPORTATION SYSTEMS MANAGEMENT AND OPERATIONS

The safe and efficient movement of people and goods is one of the 

most basic missions of any transportation agency. More and more, 

transportation agencies are realizing the importance of TSMO to help them 

achieve their safety-focused mission. 

TSMO strategies can help reduce injuries and fatalities on our roadways 

and support The Road to Zero vision.1 Significant overlap exists between 

strategies that improve operations and those that improve safety, 

including access management strategies, signal optimization, winter 

weather operations, traveler information, and traffic incident management. 

Safety strategies can have positive impacts on operations, and operational 

strategies can result in improved safety of the transportation network. 

Below are examples of TSMO strategies that have safety benefits:

 Safe, quick clearance of traffic incidents on roadways reduces the 

occurrence of secondary incidents (incidents caused by the effects 

of the original incident). One study estimates that the chance of 

secondary incidents increases by 2.8 percent for each minute the initial 

incident continues to pose a hazard.2

 Road weather management promotes safety by providing timely, 

accurate, and relevant information about roadway impacts of weather 

on travelers and transportation agencies, allowing agencies and drivers 

to make safe decisions during inclement weather. 

 Traveler information before and within work zones and in advance 

of congested slowdowns and queues can alert drivers of upcoming 

hazards, enable drivers to re-route, and create safer driver behavior. 

 Active traffic management strategies such as dynamic speed limits 

and dynamic lane control on freeways can harmonize vehicle speeds 

when congestion is building and reduce erratic flow conditions that 

lead to crashes. 

TSMO and safety are inherently linked. For example, congestion 

is a frequently cited reason drivers give for aggressive driving.3 By 

helping to reduce congestion, TSMO strategies can reduce unsafe 

Enhancing Transportation:

connecting tsmo 

and safety

WHAT IS TSMO?

Transportation systems management 

and operations (TSMO) is the use of 

strategies, technologies, mobility services, 

and programs to optimize the safety, 

mobility, and reliability of the existing 

and planned transportation system. 

A significant cause of congestion and 

unreliable travel is non-recurring events, 

such as crashes, and transportation 

network disruptions, such as bad 

weather, and special events. TSMO 

enables agencies to target the underlying 

operational causes of congestion and 

unreliable travel through innovative 

solutions that typically cost less and 

are quicker to implement than adding 

capacity. TSMO expands the range of 

mobility choices available to system 

users, including shared mobility and nonmotorized options. 

This Fact Sheet is part of a series that 

explains how TSMO relates to other 

State and local transportation agency 

functions and offices. Other Fact 

Sheets focus on how TSMO relates 

to: asset management, performance 

management, maintenance, design, 

environment, planning, human 

resources, and construction.

SAFETY

1 The Road to Zero is a vision for achieving zero roadway deaths by 2050. It is 

supported by a coalition managed by the National Safety Council and supported by 

the U.S. Department of Transportation. For more information, see: https://www.nsc.

org/road-safety/get-involved/road-to-zero.

2 SafeHighways.org, Enhancing Safety Service Patrol Driver’s Safety, 2018. Available 

at http://www.safehighways.org/safe-highway-matters/fallwinter-2013/enhancingsafety-service-patrol-drivers-safety/.

3 Stuster, J., Aggressive Driving Enforcement: Evaluations of Two Demonstration 

Programs, National Highway Traffic Safety Administration, 2004. Available at: 

https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/809707.pdf. 
ENHANCING TRANSPORTATION: CONNECTING TMSO AND SAFETY

driver behaviors. In 2018, the Texas Department of 

Transportation (DOT) renamed its Traffic Operations 

Division, where both TSMO and safety are housed, to 

the Traffic Safety Division. At the Washington State DOT, 

safety is part of its TSMO program.

Safety engineers should be part of the planning and 

implementation of TSMO strategies to ensure that the 

safety impacts of TSMO are considered. Although TSMO 

offers many safety benefits, in some instances improving 

mobility, and thus travel speeds, can increase safety risks. 

Likewise, specific safety treatments can reduce efficient 

mobility. For example, protected-only left turn signal 

phases are generally safer than permitted or protected/

permitted phasing but typically cause drivers to wait 

longer at signals. Alternatively, managed lanes often 

create differences in speed profiles with adjacent general 

use lanes that may increase safety risks. Using a datadriven, performance-based approach for both safety and 

TSMO planning will help agencies better understand 

the potential impacts of safety and TSMO strategies and 

identify the appropriate threshold for risk. Making these 

tradeoffs involves balancing the needs of different users 

of the system based on community goals and priorities.

A lack of information exists as to the safety impacts or 

crash modification factors associated with many TSMO 

strategies. The American Association of State Highway 

and Transportation Officials (AASHTO) Highway Safety 

Manual has limited information to help predict the safety 

performance of TSMO strategies. Ongoing research by 

the Federal Highway Administration (FHWA) and the 

National Cooperative Highway Research Program aims 

to address many of the knowledge gaps and support 

agencies in making important safety and mobility 

decisions. For example, the FHWA has developed 

the Intersection Control Evaluation, a data-driven, 

performance-based framework and approach. It supports 

agencies in evaluating their intersection configuration 

and control options. It also helps them to balance their 

operational, safety, and multimodal objectives.4

How Has This Worked in 

Practice?

 An Arizona study on the effectiveness of traffic signal 

coordination concluded that crash rates on intersection 

approaches decreased 6.7 percent after signal 

coordination.5

 In Virginia, researchers found nearly a 25-percent 

reduction in total crashes of all severity levels on 

segments of I-66 where hard-shoulder running was 

deployed.6

 Road weather information systems can reduce traveler 

delay and lower crash rates by 7 to 83 percent.7

 The Maryland DOT’s Coordinated Highways Action 

Response Team (CHART), which provides incident 

detection, response, and traffic management operations 

on Interstate highways and major arterials, prevents an 

estimated 225-250 secondary crashes each year.8

 In 2014, the Oregon DOT deployed an active traffic 

management system on OR 217 that included variable 

speed limits, traveler information, queue warning, and 

updated ramp metering. Preliminary crash data showed 

a 21-percent reduction in the total number of crashes 

after the first full year.9

FOR MORE INFORMATION

Joseph Gregory, Federal Highway Administration

(202) 366-0610 | Joseph.Gregory@dot.gov

FHWA-HOP-18-091

December 2018

The goal of this fact sheet is to incorporate TSMO strategies

 into routine safety planning and practices and incorporate a 

safety perspective into TSMO strategy development. This fact sheet 

raises the awareness of the benefits of employing TSMO strategies as 

approaches to safety solutions.

4 Learn more about FHWA’s Intersection Control Evaluation (ICE) at https://safety.fhwa.dot.gov/intersection/ice/.

5 FHWA, “Signalized Intersection Safety Strategies,” (Washington, DC: February 2008). Available at: https://safety.fhwa.dot.gov/intersection/

other_topics/fhwasa08008/sa4_Signal_Coordination.pdf.

6 Dutta, N., M. D. Fontaine, R. A. Boateng, and M. Campbell, Evaluation of the Impact of I-66 Active Traffic Management System: Phase II, 

Final Report Virginia Transportation Research Council (VTRC) 19-R7, October 2018. Available at: http://www.virginiadot.org/vtrc/main/

online_reports/pdf/19-R7.pdf.

7 U.S. DOT, Intelligent Transportation Systems (ITS) Joint Program Office, Investment Opportunities for Managing Transportation Performance through Technology, January 2009. 

8 Maryland DOT Coordinated Highway Action Response Team, “CHART Traffic Incident Management.” Available at: http://chart.maryland.

gov/about/incident_management.asp.

9 Oregon DOT, Portland Region 2016 Traffic Performance Report, 2016. Available at: https://www.oregon.gov/ODOT/Regions/Documents/

Region1/2016_TPR_FinalReport.pdf.