In 2008, the Federal Highway Administration (FHWA) created a document outlining 9 safety countermeasures which utilize a data driven approach to reduce serious injuries and fatalities on American highways.
According to Anthony T. Furst, Associate Administrator with the FHWA Office of Safety, these countermeasures’ implementation are tracked and monitored. Based on the most recent research, the FHWA updated the safety countermeasures in January 2012.
This week’s blog, we’ll review the first five safety countermeasures.
Signalized intersections account for about 1/3 of all intersection fatalities resulting in about 2,300 deaths and about 700 deaths in red light collisions. Many regions are now adopting roundabouts within transportation networks due to their safety and operational benefits.
Data collected by the FHWA showed that converting a two-way stop control mechanism to a roundabout can result in an 82% reduction in severe crashes and a 44% reduction in overall crashes. To convert a signalized intersection to a roundabout, it’s possible to experience a 78% reduction in severe crashes and a 48% reduction in overall crashes.
Access management is controlling access to the highways, arterials, roads as well as the entry and exits for these roadways. It also includes planning of future access needs, locations of driveways, operational needs and mobility for pedestrians and bicyclists.
Several methods of access management include driveway closure, consolidation, or relocation to restricted-movement designs for driveways, raised medians, adding auxiliary turn lanes, constructing parallel, lower speed one-way or two-way frontage roads for access, and using roundabouts to provide additional access. As a result, corridor access management can help improve traffic flow and reduce crashes and collisions.
Initially introduced in Canada in the late 1990s, backplates on traffic signals improve the visibility of the traffic signal by framing it with a retroreflective border. It is a low cost safety improvement and ensures visibility in both day/ nighttime conditions which reduces unintentional red-light running crashes as well as increasing visibility for colour blind or elderly drivers. Signals with backplates have resulted in a 15% reduction at urban, signalized intersections.
According to the FHWA, there were 8,780 single vehicle roadway departure fatalities on two-lane roads in 2009. State DOTs have been installing rumble strips in order to reduce crashes resulting from distracted, inattentive or drivers that are falling asleep at the wheel.
The FHWA have completed numerous studies and have found that centre line rumble strips can reduce head on crashes by 44% on a two-lane rural road and 64% on urban two-lane roads. Rumble strips that are on shoulders have been found to reduce crashes by 36%.
Horizontal curves account for 28% of all fatal crashes in a recent study by the FHWA. Using appropriate signals such as chevron signs or high friction surface treatments have shown high potential for improving safety on these horizontal curves. Chevron signs have been shown a 16% reduction in crashes while flashing beacons a 38-43% reduction and fluorescent curve signs a 25% reduction.
As mentioned earlier, the FHWA has utilized a data driven approach in these safety countermeasures. Understanding the capacity, traffic movements and crashes of the area and completing analysis has helped establish the needs of transportation networks and areas of improvement. Miovision’s Scout traffic data collection equipment can complete various traffic studies that can be utilized in these types of safety implementation research including average daily traffic (ADT) and turning movement counts (TMC).
Next week’s blog will feature the remaining four safety countermeasures from the FHWA.