Learn about speed management

MassDOT is committed to helping realize safer speeds across the Commonwealth to prevent serious crashes. Learn more about speed management and resources to implement speed management in your community.

Table of Contents

What is speed management?

Speed management is an approach to address speeding and speed related concerns to lower the likelihood of severe injuries or fatalities by reducing the frequency and severity of crashes. Additionally, effective speed management is critical for creating streets that support safe, comfortable, and convenient travel for everyone—whether you are in a car, on a bicycle, on foot, in a stroller, taking public transit, or using an assistive mobility device.

Speed matters. Higher speeds increase the likelihood that a crash will result in serious injury or death. A few miles per hour difference can make a big impact on a person's chance of survival.  Higher speed crashes are more forceful than lower speed crashes, resulting in more damage to the driver, passengers, the vehicle, and people and property outside of the vehicle. As speed increases, people driving lose the ability to properly observe their immediate surroundings as their field of vision narrows, and drivers require longer distances to come to a stop.

    Refer to caption for full description.

    Pedestrian Fatality and Serious injury risk; 13% at 20 mph, 40% at 30 mph, 73% at 40 mph. Cone of Vision: At 20 mph Driver able to see road and roadside, at 30 mph driver able to see roadway, at 40 mph driver can only see small portion of center of roadway.

    Speed management improves safety for all roadway users. Whether you are walking or rolling to your parked car, driving down the street, strolling to the store, getting on the bus, or riding your bike to work, the biggest transportation threat you face is the speed of a passing vehicle. Speed management creates safe conditions by reducing the likelihood that a driver will strike another vehicle and someone as they travel by foot, transit, bike, car, stroller, or wheelchair in Massachusetts.

    Speed management is critical to achieving the state's vision of a safe transportation system with zero fatalities and serious injuries on our roadways. One life lost or seriously altered is unacceptable.

    Physical changes and engineering-related roadway treatments are critical to realizing safer speeds and are the primary focus of MassDOT's speed management process. Eliminating fatal and serious injuries on our roads must be a shared responsibility. While traffic enforcement can help manage speeds in some instances, it is often not available, physically feasible, or desired. With physical roadway treatments effectively implemented, streets become self-enforcing, reducing speed related conflicts and serious crashes. Massachusetts General Law currently does not permit the use of automated enforcement.

    Recommendation steps for implementing speed management in your community

    • Collect information and analyze data. Collect information on current speeds, roadway uses, adjacent land use, and safety. It is important to review existing speed limits to identify places where speed limits no longer match the land use context, roadway design, and safety for all existing and potential roadway users.
    • Establish a target speed. Determine a target speed, the highest operating speed at which drivers should operate on a roadway in a specific context.
    • Design for speed control and separation through Roadway Treatments. Select roadway treatments based on target speed, existing speeds, and use of the roadway to effectively self-enforce driving speeds, bringing all vehicle speeds closer to the target speed. Where land use and context support higher operating speeds, more separation is needed to reduce the risk of high-speed collision by keeping vulnerable road users – those not protected by an enclosed vehicle – apart from cars and trucks.
    • Raise awareness. Promote a community-wide safe-speed culture by crafting educational messages that raise awareness about the relationship between speed and safety, implementing roadway treatment changes and safety zones. Conveying the risks of speed and the benefits of speed management design is especially important with new drivers.
    • Set speed limits. Set speed limits through speed zoning. Learn how MassDOT works with municipalities to set enforceable speed limits. If the enforceable speed limit is higher than the target speed then plan for speed management implementation and an iterative approach to achieve the best results.

    Collect information and analyze data

    It is important to collect information on current speeds, potential roadway uses, adjacent land use, and safety to identify needs and treatments that will make a difference. The data collected can be used to review existing speed limits to identify places where the speed limits need to be changed. As our communities’ change, our speed limits may no longer match the land use context, roadway design, and the need for safety for all existing and potential roadway users.

    • Community input
      • Do residents and users of the roadway feel comfortable? Have residents raised concerns about speed? Would people feel comfortable letting people of all ages use the roadway? Would you let a child walk or bike along the road?
    • The land use around the roadway
      • Do people live on or near the roadway? Are there destinations along the roadway? Is there a school? Is there senior housing? Has the land use changed?
    • Roadway characteristics
      • Are there sidewalks or facilities for people to use parallel to the roadway? Are there places for people to cross? Is there a reason why someone might want to cross the street? Are there walking and bicycle facilities separated from vehicles comfortable for people of all ages? Do pedestrians use the side of the road because no sidewalks are present?
    • Non-vehicular activity
      • Do people walk or bike along the roadway?  Are there destinations that people could walk or bicycle to? Is there transit nearby? Is there a place in the vicinity that people may opt to walk to? Consideration should be given to the fact that all vehicle trips both start and end with walking when drivers and passengers walk to and from the parked car. Use caution when considering the numbers of people currently walking and biking and consider who might use the roadway if it felt more comfortable and was safer. 
    • Crash history and risk factors
      • What is the history of crashes in the community? What are the road characteristics associated with the majority of crash locations? Have there been crashes resulting in serious injuries or death? Speed management works to address locations based on risk to proactively prevent crashes rather than just relying on existing crash history.
    • Vehicle speeds
      • What are the motor vehicle speeds along the corridor?
    • With this data in hand, the municipality and community members can work on establishing a target speed that is appropriate for the area and beneficial to all roadway users.

    Establish a target speed

    A target speed is the highest operating speed at which drivers should ideally operate on a roadway given a specific context. Over time, roadway features or uses can change, which may mean that practitioners need to revisit appropriate target speeds, rather than just defaulting to existing speed limits. In practice, these kinds of roadway evolutions can mean that while a driver may be adhering to the speed limit, they are still traveling at a speed too high for the roadway environment. As such, there is a need to evaluate the changing context and use of the roadway. Although speed limits are part of the equation, effective speed management requires a comprehensive plan that includes physical roadway features designed to control driving speeds.

    In some instances, a target speed may be high and cannot be reduced. In these instances, separation of users is needed to make it safe through treatments like sidewalks, separated bike lanes, and protected intersections.

    There are guides that can help you determine appropriate target speeds for your municipality. The National Association of City Transportation Officials provides a City Limits guide to help identify target speeds in many contexts. The Federal Highway Administration also provides a tool, USLIMITS2, to assist groups in setting target speeds who do not have an engineering background.

    Designing for speed control and separation through roadway treatments

    The core of an effective Speed Management process is using street design features that reduce motor vehicle speeds and/or physically separate different types of roadway users. Speed management creates a roadway that effectively enforces itself, lowering the likelihood of severe or fatal crash by making it uncomfortable for drivers to travel at unsafe speeds.

    Roadway treatment strategies include cost-effective, readily implemented techniques for streets of every size, traffic volume level, context, and human activity level.

    Select roadway treatments based on target speed, existing speeds, and roadway use to effectively self-enforce driving speeds, bringing all vehicle speeds closer to the target speed.  Where land use and context support higher operating speeds, more separation is needed to reduce the risk of high-speed collision by keeping vulnerable road users – those not protected inside of a motor vehicle – apart from higher-speed cars and trucks. In these cases, it is critical to find ways to separate people walking, biking, and other roadway users from cars and trucks. This can be done with separated bike lanes, sidewalks, protected intersections, and other designs. If separation is not achievable for any reason, then traffic calming should be implemented to lower vehicle speeds.

    Below is a list of different categories of roadway treatments and a link to the Speed Management Roadway Treatment technical toolkit. There you can find more details on the different types of treatments and expected speed reductions that can be realized when they are incorporated into a street or roadway network. Application of speed control and separation roadway treatments is often most successful when consistently and uniformly implemented.

    Not all roadway treatments take years and millions of dollars. Many treatments can be implemented for a couple thousand dollars within weeks. MassDOT’s Shared Streets and Spaces Grant Program can be used for funding and technical assistance to support implementation.

    All of the following roadway treatments have been successfully implemented in Massachusetts. For more information on these roadway treatments, visit the Roadway Treatment Toolkit.

    Type of roadway treatment Description

    Vertical deflection countermeasures

    Speed humps, raised pedestrian crossings, or raised intersections that raise roadways for various lengths to slow drivers.

    Horizontal countermeasures

    Median islands, chicanes or curves, or curb extensions that change the roadway. Chicanes are a series of curb extensions that alternate from one side of the street to the other, forming S-shaped curves that essentially narrow the roadway width and create an environment that slows down drivers.

    Mini roundabouts and neighborhood traffic circles

    Small-scale circular islands that act as a kind of intersection, offering yield-controlled entries and counterclockwise circulation in order to improve safety and reduce delays.

    Road diets

    Roadway configurations that involve narrowing or eliminating travel lanes to calm traffic speeds and increase safety of all roadway users. Road diets do not automatically impact throughput or cause congestion, and when it does safety is the preferred tradeoff.

    Marking measures Strategies such as optical measures and lane markings that can be used as visual cues to separate opposing traffic, signal a change in the roadway use, and help focus drivers’ attention on their speed.
    Speed transition zones, advisory, and feedback signage Strategies to slow drivers traveling from a rural to an urban environment and signs that communicate recommended speed information and feedback to drivers.

    For more information on these roadway treatments, visit the Roadway Treatment Toolkit.

    Raising awareness

    Help promote a community-wide safe-speed culture through educational messages to raise awareness about the relationship between speed and safety, roadway treatment changes for speed management, and safety zones. Here are some resources to share in your community – to residents, municipal officials, emergency responders, first-time drivers, school groups – to convey the risks of speed and the benefits of speed management design.

      Refer to below caption for full image description.

      Pedestrian Fatality and Serious injury risk; 13% at 20 mph, 40% at 30 mph, 73% at 40 mph.

      This image can be used as an alternative to the combined image in the “What is speed management“ section to help raise awareness.

      It is especially important for new drivers to be engaged and taught the importance of safe speeds and roadway safety. Messaging about the minimal time savings of driving at higher speeds compared to the risk of death and serious injury is important to express. Every mph matters: each 1 mph increase that a person drives can be attributed to a 3% increase in potential loss of life. More than 70% of all trips in Massachusetts are less than six miles. A collision at the higher speed, however, almost doubles the risk of death or serious injuries for pedestrians. Town events, marketing, and school programs highlighting the importance of safe speeds helps new and experienced drivers learn safe driving tips.

      Set speed limits

      The goal of speed zoning as part of the speed management process is to confirm that the target speed has been achieved and to set an enforceable speed limit. If the target speed has not been met, additional roadway treatments should be implemented to get closer to the target speed. To learn about setting speed limits, go to About the role of speed limits.

      Take action and learn more

      1. Public: Reach out to municipal government to voice concerns and share speed management information.
      2. Municipalities: Work closely with members of the public and MassDOT to define areas where roadway safety can be improved. Additionally, municipalities initiate and implement speed management roadway treatments and speed zoning studies.
      3. MassDOT: Work closely with municipalities to help them conduct speed studies and implement speed management. MassDOT also signs official speed limits into law.

      Contact

      Online

      MassDOT State Traffic Engineer StateTrafficEngineer@dot.state.ma.us

      Address

      10 Park Plaza, Suite 7520
      Boston, MA 02116
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