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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
Date:
Winter 2022
Issue No:
Vol. 85 No. 4
Publication Number:
FHWA-HRT-22-002
Table of Contents

Speed Management is Key to Road Safety

by Guan Xu, Abdul Zineddin, Randolph Atkins, and Sarah Abel
"Image of car speedometer showing zero miles per hour. Photo Source: © Joshua Fulle / Unsplash.com."
Speed management is a critical element of the Safe System Approach.

Much progress has been made in transportation safety over the last several decades. Despite the large increase in traffic volume, the fatality rate decreased from 5.5 fatalities per 100 million vehicle miles traveled (VMT) in 1966 to 1.11 fatalities in 2019. Despite this success, reducing traffic speeds and speeding-related crashes and fatalities continue to pose some complex challenges. Early estimates show that fatality rates and speeding-related fatalities increased in 2020 during the COVID-19 public health emergency, compared to 2019, although 2020 was anomalous.

Studies clearly show that higher speeds result in greater impact at the time of a crash, which leads to more severe injuries and fatalities. This is especially concerning for more vulnerable road users, such as motorcyclists, bicyclists, and pedestrians. Per vehicle miles traveled in 2019, motorcyclist fatalities occurred nearly 29 times more frequently than passenger car occupant fatalities, and 33 percent of motorcycle riders involved in fatal crashes in 2019 were speeding. Pedestrians made up 17 percent of traffic fatalities in 2019 with 6,205 fatalities. Bicyclists accounted for approximately 2 percent of fatalities in 2019 with 846 bicyclist fatalities.

"An infographic showing three car speedometers indicating speed and the average risk of death to a pedestrian if struck at the indicated speed. The first shows 23 miles per hour with a 10 percent risk of pedestrian death. The second shows 42 miles per hour with a 50 percent risk of pedestrian death. The third shows 58 miles per hour with a 90 percent risk of pedestrian death. Image Source: Federal Highway Administration. Based on data from the AAA Foundation for Traffic Safety, Impact Speed and a Pedestrian’s Risk of Severe Injury or Death, September 2011."

 

The greater the speed of a vehicle at the time of a crash, the higher the risk of death for a pedestrian struck.

Because higher speeds increase fatalities, new approaches in speed management, such as the Safe System Approach, are needed to reduce roadway fatalities and increase the safety of all road users. Underscoring the importance of this issue, the National Transportation Safety Board has identified both “implement a comprehensive strategy to eliminate speeding-related crashes” and “protect vulnerable road users through a Safe System Approach” as part of its 2021–2022 Most Wanted List of transportation safety improvements (found at www.ntsb.gov/safety/mwl/Pages/default.aspx).

Speeding as a Safety Problem 

The National Highway Traffic Safety Administration defines a crash as speeding-related if any driver involved in the crash is charged with a speeding-related offense or if a police officer indicates racing, driving too fast for conditions, or exceeding the posted speed limit was a contributing factor in a crash. The most recent data from NHTSA’s Fatality Analysis Reporting System (FARS) found that, in 2019, there were 9,478 speeding-related fatalities, 26 percent of total traffic fatalities for the year. For speeding-related fatalities where functional class was reported, 86 percent occurred on noninterstate roadways. Drivers in speeding-related fatal crashes were more likely to have previous convictions for speeding and/or alcohol-impaired (BAC .08 g/dL or higher) driving, previous crashes, and license suspensions or revocations compared to nonspeeding drivers in fatal crashes.

"A speed feedback sign showing vehicle speed upon approach of advisory speed zone along highway curve. The listed speed limit is 45 miles per hour, and the feedback sign reads “Your speed is 68 MPH.” Photo Source: © Portland State University."
Speed feedback signs like this one can encourage drivers to follow posted speed limits and advisory warnings.

NHTSA’s nationally representative survey of traffic speeds across the United States conducted in 2015 revealed that 70 percent of free-flow vehicles on limited access roads exceeded the posted speed limit, with 59 percent of vehicles on major arterials and 60 percent of vehicles on minor arterials and collector roads also exceeding the posted speed limit. The 85th percentile speeds were significantly higher in 2015 on major arterials and minor arterials and collector roads as compared to the previous national survey in 2009. The full survey is available at https://rosap.ntl.bts.gov/view/dot/35961.

The COVID-19 public health emergency made excessive speeding behaviors more evident. Traffic speeds across the country increased during this same period compared to historical levels, especially on urban interstates, with many reports of drivers traveling at extremely high speeds in excess of 100 miles (160 kilometers) per hour. In 2020, while VMT decreased 13.2 percent, the fatality rate increased to 1.37 fatalities per 100 million VMT, up from 1.11 in 2019, with a projected 7.2 percent increase in fatalities and an 11 percent increase in speeding-related fatalities. The evidence indicates that a combination of less congested roads and a higher percentage of riskier drivers contributed to this increase.

Many factors contribute to drivers’ choice of speeding, but drivers’ beliefs and attitudes play an important role in their driving behavior and the cultural acceptance related to speeding. For instance, NHTSA’s naturalistic driving study, “Motivations for Speeding,” showed that driver motivations, attitudes, and beliefs are “highly significant predictors” of which drivers speed and how much they speed. Several studies identified speed-contributing attitudes such as being impatient with other drivers, wanting to get where they are going as fast as possible, enjoying driving fast, and believing that driving fast was not dangerous for skilled drivers.

Transportation professionals have realized that creating a positive traffic safety culture is critical to addressing speeding as a safety problem. All five elements of the Safe System Approach can be applied to addressing speeding; however, the safe speeds and safe roads elements are of particular importance when creating a successful speed management program and advancing speed management for safety.

"The five elements of a Safe System Approach with descriptions of each. The first is safe road users, with the following text: “The Safe System Approach addresses the safety of all road users, including those who walk, bike, drive, ride transit, and travel by other modes.” The second element is safe vehicles, with the following text: “Vehicles are designed and regulated to minimize the occurrence and severity of collisions using safety measures that incorporate the latest technology.” The third element, which has a red border around it indicating the focus of this article, is safe speeds, with the following text: “Humans are unlikely to survive high-speed crashes. Reducing speeds can accommodate human injury tolerances in three ways: reducing impact forces, providing additional time for drivers to stop, and improving visibility.” The fourth element is safe roads, with the following text: “Designing to accommodate human mistakes and injury tolerance can greatly reduce the severity of crashes that do occur. Examples include physically separating people traveling at different speeds, providing dedicated times for different users to move through a space, and alerting users to hazards and other road users.” The fifth element is post-crash care, with the following text: “When a person is injured in a collision, they rely on emergency first responders to quickly locate them, stabilize their injury, and transport them to medical facilities. Post-crash care also includes forensic analysis at the crash site, traffic incident management, and other activities. Photo Source: Source: FHWA."
Safe speeds is one of the five elements of the Safe System Approach. Applying safe speeds reduces impact forces, increases visibility and decreases stopping distance.

The Importance of Speed Management 

When drivers are traveling at higher speeds, they require more time to react once they see changes in the road environment ahead. Once they engage the brakes, the distance required to stop the vehicle is directly related to the speed of the vehicle at the time of braking and the vehicle’s weight; higher speeds and heavier vehicles simply take longer to stop, so consequently these factors result in the increased probability of crashes. Speed also impacts the severity of a crash. The force involved in a crash is directly related to the speed at the time of a crash: “The energy release is proportional to the square of the impact speed,” according to the Transportation Research Board’s Special Report 254: Managing Speed – Review of Current Practice for Setting and Enforcing Speed Limits. These factors show how effective speed management using the Safe System Approach, defined as kinetic energy management, can contribute to reducing speeding-related serious injuries and fatalities.

"A graph with horizontal bars illustrating perception/reaction and stopping distance traveled by vehicles under different speeds from 20mph to 60mph respectively in 10mph increment. 20mph shows 44' perception/reaction and 38' stopping distance. 30mph shows 66' perception/reaction and 86' stopping distance. 40mph shows 88' perception/reaction and 154' stopping distance. 50mph shows 110' perception/reaction and 240' stopping distance. 60mph shows 132' perception/reaction and 346' stopping distance. Photo Source: Source: FHWA."
This graph shows distance traveled for perception/reaction and stopping by speed. Once a driver begins reacting, the vehicle travels a greater distance during an evasive maneuver, the driver has a reduced ability to steer around objects in the roadway, there is an increased risk that “an evasive steering maneuver will result in loss of control,” and more stopping distance is required.

Speed management is an approach that focuses on achieving safe mobility by setting appropriate speed limits, reducing speeding, and reducing and/or mitigating the impact of speeding-related crashes. The goal of the U.S. Department of Transportation speed management program is to improve public health and safety by reducing speeding-related fatalities and injuries and achieve improved safety experience for all road users. The following key speed management strategies and activities for achieving the USDOT speed management program goal were identified by the USDOT intermodal Speed Management Team that consists of NHTSA, FHWA, and the Federal Motor Carrier 
Safety Administration:

  • Developing and implementing jurisdiction-wide speed management programs and plans.
  • Outlining how to set safe, consistent, and enforceable speed limits based on the presence of all road users and context and not just drivers’ operating speeds.
  • Applying proven safety countermeasures to help achieve safe speeds for the safety of all roadway users.
  • Improving crash data report forms with targeted reporting of speeding-related crashes that provides consistency and focuses on identifying contributing factors.
  • Deploying enforcement through transparent high-visibility activities, educational programs, and awareness campaigns rather than a strictly enforcement focus.
  • Considering equity in speed management decision making.

The team is currently updating the USDOT Speed Enforcement Camera Systems Operational Guidelines. The updated guide is expected to be renamed Speed Safety Camera Program Planning and Operations Guide and will emphasize that speed cameras are an effective countermeasure to improve safety by managing traffic speeds.

Noteworthy safety programs recognize safe speeds as a key factor to achieving a goal of zero traffic deaths and serious injuries. All zero-death programs reference the Safe System Approach for achieving safe speeds, and the need to create a positive traffic safety culture and improve driver behavior as a part of effective speed management.

The safe speeds element of the Safe System Approach can be reached through a comprehensive speed management program. There are challenges and opportunities when considering speed management in relation to the Safe System Approach. These include how to define safe speeds consistently across all contexts, how to effectively set safe speed limits that do not rely solely on driver operating speeds, how to achieve a target speed using roadway geometry effectively, and how to incorporate the concepts of kinetic energy forces and speed harmonization in existing speed management guidance. To address the challenges, a joint effort by FHWA and the Institute of Transportation Engineers (ITE) is currently developing additional resources as speed management practices shift toward applying the Safe System Approach.

"Road crews in Portland replace speed limit signs. Photo Source: © Hannah Schafer, Portland Bureau of Transportation."
The city of Portland, OR, has adopted a new speed limit of 20 miles (32 kilometers) per hour on nearly 70 percent of city streets as part of comprehensive speed management program.

FHWA: Working Toward Better Understanding and Managing of Speed 

Speeding and speed management are cross-cutting and complex challenges involving the interaction of many factors, including effective roadway design, posted speed limits, political climate, road user behavior, enforcement strategies, and judicial decisions. Collaboration is the key to combat speeding as a safety problem. National agencies and organizations, such as FHWA, NHTSA, and ITE, provide resources and technical assistance on safety through speed management.

FHWA has been focusing on setting appropriate, consistent, and enforceable speed limits and providing technical assistance to State and local agencies on implementing effective infrastructure and engineering speed management countermeasures to encourage drivers to obey speed limits. Through its Proven Safety Countermeasure Initiatives program, FHWA is promoting, with technical support, the implementation of several proven speed management countermeasures including variable speed limit system, speed safety camera, and setting appropriate speed limits for all road users. Recently, FHWA began a new program to explore concepts and techniques to integrate the Safe System Approach with speed management.

"An urban roadway and intersection with vehicle, bicyclists, and pedestrians. Photo Source: © Getty Images."
Safe speeds, one of the five elements of the Safe System Approach, are critical for all road users.

Speed management is receiving increased attention from State and local agencies, especially those that have adopted Vision Zero goals and are beginning to implement the Safe System Approach. Forty-four States have included speeding or speed management in their Strategic Highway Safety Plans. A comprehensive speed management program is crucial to ensure that agencies can work collaboratively to address safe speeds in a holistic approach. Speed management program plans set objectives, identify gaps and needs, lay out strategies and planned activities, and incorporate state-of-practices for successfully implementing speed management programs. FHWA has been providing direct technical assistance and has helped some agencies successfully develop and implement speed management program plans. Some of the recently developed program plans include recommendations and strategies to help advance a positive traffic safety culture and application of the Safe System Approach.

In recent years, FHWA has endeavored to update existing, and create new, speed management resources for practitioners and provide technical assistance for speed management. This includes the recently published report, Noteworthy Speed Management Practices (FHWA-SA-20-047, https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa20047/fhwasa20047.pdf), which includes examples of successful implementations of speed management countermeasures by public agencies on:

  • Developing and implementing a city-wide Strategic Speed Management Program with comprehensive speed management activities, established key indicators, target achievement metrics, and an integrated effort including enforcement;
  • Setting safe, consistent, and enforceable speed limits for all roadway users for rural and urban environments;
  • Applying engineering and alternate enforcement countermeasures, such as self-enforcing roadway and speed safety cameras, to achieve the set posted speed limits for the safety of all roadway users;
  • Improving crash data forms with targeted reporting of speeding-related crashes that provide consistency and focus on addressing crashes by identifying contributing factors; and
  • Implementing enforcement through transparency and using an “educational” initiative rather than a strict enforcement detail.

In addition, FHWA has also increased education and training for more transportation professionals on USLIMITS2, a web-based tool for setting safe speed limits. With the support of the National Cooperative Highway Research Program (NCHRP), FHWA is in the process of developing the next generation of the tool, USLIMITS3, which will incorporate state-of-the-practice research and methods, such as the Safe System Approach, for setting safe speed limits for all road users.

NHTSA Speed Management Activities 

The efforts of NHTSA’s speed management program focus on the Safe System Approach for enforcement, education, emergency response, vehicle safety, and behavioral research to develop safety countermeasures, as well as providing resources and technical assistance to support practitioners at the State and local levels (www.nhtsa.gov/risky-driving/speeding#resources). The agency works closely with law enforcement organizations through its Law Enforcement Liaison Program. It also works with the National Institute on Standards and Technology to establish model specifications for speed measurement devices and maintains a “Conforming Product List” of devices that meet the specifications. Additionally, NHTSA provides training and guidance for using these devices as well as other training for law enforcement personnel, including a High Visibility Enforcement Toolkit.

NHTSA provides training for traffic safety professionals through its speed management course, taught by the Transportation Safety Institute, and issues communications to educate the driving public on speed safety and preventing speeding. The agency also conducts a wide range of innovative research projects to identify safety problems; advance scientific knowledge in this area; and support the development of countermeasures to equitably improve speed management and reduce traffic crashes, injuries, and fatalities, including producing a report on effective countermeasures entitled Countermeasures That Work. Additionally, NHTSA supports emergency medical response efforts for crashes and offers a robust vehicle safety program to improve vehicle crashworthiness, occupant protection, and crash avoidance technologies.

“Speeding is one of the top causes for vehicle crashes,” says Nanda Srinivasan, NHTSA’s associate administrator for Research and Program Development. “Speeding endangers everyone—the driver, occupants, and other road users. There is no excuse to speed—whether you are late, [or] the roads are empty or congested.”

"A roadway with “25 MPH” painted on it alongside the standard speed limit sign. Photo Source: © Shauna Hallmark."
Ossian, IA, received a Manual on Uniform Devices experimental waiver for this high-visibility pavement marking to increase compliance with posted speed limit.

ITE’s Efforts in Speed Management 

ITE continually focuses on advancing speed management for safety, providing updated resources and guidance as speeding-related information rapidly evolves. In 2019, ITE released a resource hub that includes available speed management resources helpful to transportation professionals (www.ite.org/technical-resources/topics/speed-management-for-safety).

In partnership with the Vision Zero Network, ITE has conducted several “speed management for safety” workshops to assist agencies with implementing a safe and comprehensive approach to speed management, from helping outline program goals to methods for setting speed limits to effective roadway design to manage speeds. After conducting a workshop in the city of Austin, TX, they went on to adopt a comprehensive speed management program upon the conclusion of the workshop held there in 2019, and FHWA featured the Austin speed management program for its successes in the Noteworthy Speed Management Practices (FHWA-SA-20-047) publication the following year. One of Austin’s most recent speed management successes took place in June 2020, when the city council unanimously voted to reduce speed limits on residential, urban arterial, and downtown streets.

In 2021, the Vision Zero Network and ITE conduced “speed management for safety” workshops in three California communities to help develop and sustain effective speed management safety programs as the state of California continues to look for ways to further advance safe speeds. Most recently, ITE commented on speed-limit-setting guidance in the proposed amendments to the Manual on Uniform Traffic Control Devices, and it is beginning a joint effort with FHWA to explore ways to further advance the Safe System Approach through achieving target speeds.

“Safe speeds are a key component of the Safe System Approach and critical to achieving Vision Zero,” says Jeffrey F. Paniati, P.E., ITE’s executive director and CEO. “An effective speed management program can only be created and maintained through strong partnerships among those with responsibility for planning, design, operations, and enforcement on the roadway system.”

"A fire truck drives over a speed cushion on a residential street. Photo Source: © Traffic Logix."
Speed management countermeasures for residential streets may include speed cushions like these, which calm vehicle traffic but include wheel cutouts that allow fire apparatuses to bypass in case of emergence response.

Looking Ahead 

USDOT continues to work diligently to make equitable and effective speed management a priority throughout the country by conducting cutting-edge research and providing crucial resources to support State and local speed management efforts to reduce speeding-related injuries and fatalities. The recent commitment to the Safe System Approach holds great promise and has proven effective internationally as a method for setting safe speed limits and working toward a goal of zero roadway fatalities. Tackling speeding-related safety issues though the incorporation of new concepts, approaches, and technologies with traditional speed management can reduce the country’s speeding problem and improve overall traffic safety.

“We are committed to championing the Safe System Approach and working with our partners to achieve safe speeds for all road users,” says Michael S. Griffith, the director of FHWA’s Office of Safety Technologies.

Undoubtedly, there will be new challenges in the future as practices advance. The Safe System Approach, which considers all road users of the transportation system and new technologies in vehicles and infrastructure, offers opportunity and promise for reducing speeding-related injuries and fatalities. Whatever the challenges that arise related to speeding, USDOT and its partners are prepared to address them through comprehensive speed management as part of the implementation of the Safe System Approach.

Guan Xu, P.E., is a highway engineer with FHWA’s Office of Safety Technologies, where she manages the Speed Management Safety program. She holds an M.S. in civil engineering from the University of Cincinnati.

Abdul Zineddin serves as the leader of the Safety Operations Team for FHWA’s Office of Safety. He provides oversight of safety issues related to pedestrians, bicyclists, intersections, speed management, connected and automated vehicles, and local and rural roads. He has a B.S., M.S., and Ph.D. in civil engineering from Penn State University.

Randolph Atkins is the chief of NHTSA’s Behavioral Research Division. He oversees behavioral research on speeding, impaired driving and motorcycle, pedestrian, and bicycle safety and has led numerous studies on speeding and traffic safety. He holds a B.A., M.A., and Ph.D. in sociology from the University of Virginia.

Sarah Abel, RSP1, is the sustainable safety practice lead at Toole Design and was formerly the transportation planning director at ITE. Her work primarily focuses on transportation planning, speed management, and vulnerable road user safety. She serves on the steering committee of the National Complete Streets Coalition and on the Bicycle Technical Committee of the National Committee on Uniform Traffic Control Devices.

For more resources on speed management, visit https://safety.fhwa.dot.gov/speedmgt.