Understanding the current state of the practice can help practitioners both to identify gaps and needs within an agency's speed management policies and practices as well as to select successful strategies for addressing speed-related crashes.
2.1 Policies and Procedures
There is a wide variety of policies, practices, and procedures regarding speed management across the United States. Some States have their own manual of uniform traffic control devices, traffic studies manuals, guidelines, or other policies and procedures regarding speed management. Others do not have jurisdiction-specific speed management policies or guidance available to their practitioners. When States develop their own manual on uniform traffic control devices or supplement the national version, they often include additional guidance on setting speed limits or placing signs and markings. For example, Arizona Department of Transportation (DOT) developed a supplement to the national Manual on Uniform Traffic Control Devices and added information on items such as photo enforcement, speed hump markings, and additional guidelines on school zones. Florida DOT created Speed Zoning for Highways, Roads, and Streets in Florida, a manual that provides guidelines and recommended procedures for establishing uniform speed zones on roadways throughout the State. Massachusetts DOT also has established procedures for speed zoning on State and municipal roadways. Iowa DOT has an online traffic and safety manual that includes information on the process for establishing speed limits and completing speed studies.
Some transportation agencies have gone further and created their own traffic calming manuals or handbooks, which provides detailed guidance regarding the appropriate use, design, and implementation of traffic calming measures. Delaware DOT's manual is intended to help encourage closer adherence to posted speeds, discourage cut-through traffic, and enhance user safety and community aesthetics. Pennsylvania's Traffic Calming Handbook provides guidance for the State DOT and municipalities for implementing traffic calming measures throughout the State.
Overall, while many States have developed general speed management policies and guidance on setting speed limits and completing speed studies, researchers identified many State and local agencies that lacked documentation regarding the methods or procedures to identify speeding-related crash problems within the roadway departure, intersection, and pedestrian safety focus areas.
2.2 Safety Plans and Focus Areas
With regard to State Strategic Highway Safety Plans (SHSP), all States reference speeding in their plans, although mostly in the context of enforcement and aggressive driving. Several States list roadway departure, intersections, and pedestrians as emphasis areas, but most of these do not include a specific mention of speeding as a contributing factor, nor do they identify speeding-related countermeasures.
The following summary is based on information available as of January 2015.
Fifteen States included speed management actions in their SHSP as part of a roadway departure emphasis area. These states apply strategies such as:
- Targeted corridor education and enforcement
- Advance warning signs
- Flashing beacons
- Curve markings on pavement
- Rumble strips
- Safety Edge SM9
- Transverse lines with decreasing spacing
- Edge lines for lane narrowing.
Nine States included speed management actions as part of their intersection emphasis area. These states utilize strategies such as:
- Targeted speed enforcement
- Implementation of automated enforcement
- Education and outreach
- Pavement friction improvements at locations with wet pavement crash history
- Advanced warning flashers to inform drivers of a need to stop at high speed signalized intersections
- Rural intersection warning and decision support systems
- Installation of medians within the influence of intersection approaches.
Seven States included speed management actions as part of their strategic plans for pedestrians. These states employ strategies such as:
- Installation of medians near intersections
- Clearly marked crosswalks
- High intensity activated crosswalk beacons
- Rectangular rapid flash beacons
- Traffic calming techniques (e.g., speed humps, bulb-outs, street trees, on-street parking)
- Road Diets
- Education and outreach.
The attention to speeding issues varies widely across the State SHSPs, with some States providing minimum mention of speeding as part of a broader aggressive driving focus, and others providing greater details and targets related to speeding-related crashes.
In recent years, more than 20 State DOTs and a number of local agencies have developed focused safety action or implementation plans. FHWA continues to support development of State-level Roadway Departure Action Plans and Intersection Action Plans – efforts that began in 2008. Each plan includes analysis of speeding-related crashes and recommends engineering, enforcement, and education countermeasures to reduce speeding-related roadway departure or intersection-related crashes. The plans estimate the cost of these strategies and the benefits of each in terms of reduced annual traffic crashes, severe injuries, and fatalities. To date, FHWA has led development of more than 35 of these plans.
Many State DOTs and local communities recognize the need to address pedestrian crashes and have developed pedestrian action plans which include a range of countermeasures to reduce pedestrian- motor vehicle crashes. Although speed reduction is a significant focus of these pedestrian action plans, some plans are more robust than others.
2.3 Research Publications and Guidance
Many research publications and guidance documents address speed management, speeding-related crashes, and speeding countermeasures in general, but the relevance to the three focus areas varies. The FHWA Office of Safety - Speed Management website contains links to resources and a wide range of engineering measures for managing speed in addition to each's effect on speed and safety.10
Other available literature, such as NCHRP Report 500 – Volume 23: A Guide for Reducing Speeding- related Crashes, provides solid guidance regarding engineering and law enforcement strategies and countermeasures to reduce the risk of speeding-related crashes.11 For a more comprehensive list of speed management-related resources, see Appendix C.
2.4 Future Opportunities
In summary, there are many opportunities for agencies to enhance their speed management programs, whether by improving policies on setting speed limits, defining speeding-related data analysis process, or incorporating more speed management techniques or countermeasures within safety action plans. Additional information on how to identify and deploy strategies that will support the goal of enhancing speed management programs is discussed in Chapter 3
9 Safety EdgeSM provides a transition for vehicles to return to the pavement more smoothly and easily by shaping the edge of pavement to 30 degrees and eliminating vertical drop-off. More information on Safety EdgeSM is available at https://www.fhwa.dot.gov/innovation/everydaycounts/edc-1/safetyedge.cfm. [ Return to note 9. ]
11 T.R. Neuman, K.L. Slack, K.K. Hardy, V.L. Bond, et al. NCHRP 500 – Volume 23: A Guide for Reducing Speed-Related Crashes, Transportation Research Board of the National Academies, (Washington, DC: TRB, 2009). Available at: http://www.trb.org/Main/Blurbs/160862.aspx. [ Return to note 11 . ]