FHWA Proven Safety Countermeasures
In 2008, FHWA began promoting infrastructure-oriented safety treatments and strategies, chosen based on proven effectiveness and benefits, to encourage widespread implementation by state, tribal, and local transportation agencies to reduce serious injuries and fatalities on American highways. Some are common-sense low-cost improvements, others capitalize on innovative technology, but the approach itself soon evolved to become the Proven Safety Countermeasures (PSC) initiative, which FHA updates periodically.
As of today, FHWA's PSC initiative has yielded a collection of 28 countermeasures and strategies that are indeed effective at reducing roadway fatalities and serious injuries. Transportation agencies are strongly encouraged to consider widespread implementation of these PSCs to accelerate the achievement of local, state, and national safety coals.
All PSCs are designed for all road users and all kinds of roads, ranging from rural to urban, from high-volume freeways to low-volume state/county roads, from signalized crossings to horizontal curves, and everything in between. Each countermeasure addresses at least one safety focus area (speed management, intersections, roadway departures, or pedestrians/bicyclists) while others represent crosscutting strategies that address multiple safety focus areas.
Below are FHWA's 28 proven safety countermeasures, organized by their safety focus area:
Speed Management
Appropriate Speed Limits for All Road Users - Addressing speed is fundamental to the Safe System Approach to making streets safer, and a growing body of research shows that speed limit changes alone can lead to measurable declines in speeds and crashes.
Speed Safety Cameras - 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.
Variable Speed Limits - VSLs use prevailing information on the roadway, like traffic speed, volumes, weather, and road surface conditions, to determine appropriate speeds and display them to drivers.
Pedestrian/Bicyclist
Bicycle Lanes - Providing bicycle facilities can mitigate or prevent interactions, conflicts, and crashes between bicyclists and motor vehicles, and create a network of safer roadways for bicycling. Adding a bicycle lane to an urban four-lane undivided road can reduce total crashes by up to 49 percent.
Crosswalk Visibility Enhancements - Poor lighting conditions, obstructions, and roadway curvature can reduce visibility at crosswalks. Simple countermeasures like high-visibility crosswalks, lighting, and signing/pavement markings can reduce pedestrian injury crashes by up to 40 percent.
Leading Pedestrian Interval - Giving pedestrians a three to seven-second head start into intersections can help establish their priority over vehicles turning left and can reduce related crashes by 13 percent.
Medians & Pedestrian Refuge Islands in Urban & Suburban Areas - Installing a median or pedestrian refuge island can help improve safety by allowing pedestrians to cross one direction of traffic at a time. In urban and suburban areas, these countermeasures can reduce pedestrian crashes by up to 56 percent.
Pedestrian Hybrid Beacons - The pedestrian hybrid beacon (PHB) is a traffic control device designed to help pedestrians safelv cross higher-speed roadways at midblock crossings and uncontrolled intersections. Consisting of two red lenses above a single yellow lens, PHBs can reduce pedestrian crashes by 55 percent.
Rectangular Rapid Flashing Beacons - To enhance pedestrian conspicuity and increase driver awareness at uncontrolled, marked crosswalks, transportation agencies can install a pedestrian actuated Rectangular Rapid Flashing Beacon (RRFB), which are shown to reduce pedestrian crashes by up to 47 percent.
Road Diets (Roadway Configuration) - A road reconfiguration, also known as a "diet", converts a four-lane undivided roadway into three lanes, with the center lane dedicated to turning. This strategy can reduce overall vehicle crashes up to 47 percent.
Walkways - With more than 50,000 pedestrian deaths each year, basic improvements such as increasing the number of walkways, paths, and sidewalks can make a big difference. Adding paved shoulders can also reduce crashes with pedestrians who walk along roadways by 71 percent.
Roadway Departure
Enhanced Delineation for Horizontal Curves - Enhanced delineation treatments can alert drivers to upcoming curves, the direction and sharpness of the curve, and appropriate operating speed. Just adding highly visible, chevron warning signs can reduce nighttime crashes by 25 percent.
Longitudinal Rumble Strips & Stripes on Two-Lane Roads - With roadway departure crashes accounting for more than half of the fatal roadway crashes annually in the U.S., approaches like rumble strips or stripes can be deployed to alert distracted, drowsy, or otherwise inattentive drivers who drift from their lane.
Median Barriers - Median barriers, such as cable, concrete, or beam guardrails, can mitigate head-on collisions from cars traveling in opposite directions. When installed on rural four-lane freeways, barriers can reduce cross-median crashes by 97 percent.
Roadside Design Improvements at Curves - Guardrails, cable barriers, and concrete barriers protect drivers from hazards. Increasing a clear zone to 30 feet can reduce crashes by 44 percent. Slope flattening and wider shoulders aid in accident recovery as well.
SafetyEdge - This technology shapes the pavement edge to provide a 30-degree transition off-road instead of a sudden drop-off. This allows drivers who drift off the road to safely recover without losing control of their vehicles. Deploying SafetyEdge can reduce dangerous crashes by 11 percent.
Wider Edge Lines - Wider edge lines enhance the visibility of travel lane boundaries as compared to traditional edge lines. Edge lines are considered “wider” when the marking width is increased from the minimum normal line width of 4 inches to the maximum normal line width of 6 inches.