U.S. Department of Transportation
Federal Highway Administration
Safe Speeds is a core principle of the Safe System Approach since humans are less likely to survive high-speed crashes. Enforcing safe speeds has been challenging; however, with more information and tools communities can make progress in reducing speeds. Agencies can use speed safety cameras (SSCs) as an effective and reliable technology to supplement more traditional methods of enforcement, engineering measures, and education to alter the social norms of speeding. SSCs use speed measurement devices to detect speeding and capture photographic or video evidence of vehicles that are violating a set speed threshold.
Agencies should conduct a network analysis of speeding-related crashes to identify locations to implement SSCs. The analysis can include scope (e.g., widespread, localized), location types (e.g., urban/suburban/rural, work zones, residential, school zones), roadway types (e.g., expressways, arterials, local streets), times of day, and road users most affected by speed-related crashes (e.g., pedestrians, bicyclists).
SSCs can be deployed as:
- Fixed units—a single, stationary camera targeting one location.
- Point-to-Point (P2P) units—multiple cameras to capture average speed over a certain distance.
- Mobile units—a portable camera, generally in a vehicle or trailer.
The table below describes suitable circumstances for SSC deployment.1
|Considerations for Selection||Fixed||P2P||Mobile|
|Problems are long-term and site-specific.||X||X|
|Problems are network-wide, and shift based on enforcement efforts.||X|
|Speeds at enforcement site vary largely from downstream sites.||X||X|
|Overt enforcement is legally required.||X||X||X|
|Sight distance for the enforcement unit is limited.||X||X|
|Enforcement sites are multilane facilities.||X||X|
- SSCs can produce a crash reduction upstream and downstream, thus generating a spillover effect.2
- Public trust is essential for any type of enforcement. With proper controls in place, SSCs can offer fair and equitable enforcement of speeding, regardless of driver age, race, gender, or socio-economic status. SSCs should be planned with community input and equity impacts in mind.
- Using both overt (i.e., highly visible) and covert (i.e., hidden) enforcement may encourage drivers to comply with limits everywhere, not only at sites they are aware are enforced.
- Agencies should conduct evaluations regularly to determine if SSCs are accomplishing safety goals and whether changes in strategy, scheduling, communications, or public engagement are necessary.
- Agencies should conduct a legal and policy review to determine if SSCs are authorized within a jurisdiction and how the authorization and other traffic laws will affect a SSC program.
- Agencies should develop an SSC program plan with consideration of the USDOT SSC guidelines for planning, public involvement, stakeholder coordination, implementation, maintenance, evaluation, etc.3
1. Thomas et al. Speed Safety Camera Program Planning and Operations Guide. FHWA, (2021).
2. Montella et al. ”Effects on speed and safety of point-to-point speed enforcement systems“. Accident Analysis and Prevention, Vol. 75, (2015). Note that this is an international study.
3. Speed Enforcement Camera Systems Operational Guidelines. NHTSA, (2008).
4. Shin et al. ”Evaluation of the Scottsdale Loop 101 automated speed enforcement demonstration program.“ Accident Analysis and Prevention, Vol. 41, (2009).
5. Li et al. ”A Before-and-After Empirical Bayes Evaluation of Automated Mobile Speed Enforcement on Urban Arterial Roads.“ Presented at the 94th Annual Meeting of the Transportation Research Board, Paper No. 15-1563, Washington, D.C., (2015). Note that this is an international study.
6. Automated Speed Enforcement Program Report 2014-2017. New York City DOT, (2018).