Top of Page
From Tech Transfer Newsletter
This document is found at
www.techtransfer.berkeley.edu/newsletter/08-4_09-1/strategy.php
We are pleased to present one of the Federal Highway Administration's Intersection Safety Strategies, as described in NCHRP Report 500, Volume 5, A Guide for Addressing Unsignalized Intersection Collisions.
Signalized intersections with high frequencies of pedestrian and/or bicycle crashes and on routes serving schools or other generators of pedestrian and bicycle traffic.
The mix of travel modes at intersections, along with the possibility of vehicle-to-vehicle conflicts, can create safety and operational concerns for non-motorists. Geometric or physical improvements that can be made to an intersection to increase pedestrian safety include the provision of the following:
Some of the problems facing bicyclists at intersections include high-traffic volumes and speeds and the lack of space for bikes. Possible improvement projects include the following:
A key to successful pedestrian and bicycle facilities is careful planning. The network of facilities should be well connected to meet the needs of the community.
Landscaped medians should not obstruct visibility between pedestrians and bicyclists and approaching motorists or include objects representing a collision hazard to vehicles that may run onto the median.
Agencies must overcome decades of street and road construction projects that may have routinely ignored the needs of pedestrians and bicyclists. Pro-pedestrian and bicyclist policies and construction programs need to be implemented to correct this problem. Refuge islands may conflict with the need to provide open pavement for right-turning traffic with large turning paths. A right-turn slip lane can accommodate vehicles with large turning paths but should discourage high-speed vehicle turns and improve the right-turning motorist's view of other users.
Many treatments addressing pedestrian and bicyclist improvements can be implemented in relatively short time frames.
Costs will vary depending on the treatment implemented. Many are low cost in nature. Others, such as overpasses and lane widening, will cost significantly more.
The presence of sidewalks on both sides of the street has proven to significantly reduce the "walking along roadway" pedestrian crash risk compared to locations where no sidewalks/walkways exist. Reductions of 50% to 90% of these types of pedestrian crashes have occurred. The Federal Highway Administration found that a raised median (or raised crossing island) was associated with a significantly lower pedestrian crash rate at multilane crossing locations, with both marked (46% reduction) and unmarked (39% reduction) crosswalks. In contrast, painted (not raised) medians and center two-way left-turn lanes did not offer significant safety benefits to pedestrians on multilane roads, compared to no median at all. A Danish study concluded that providing bicycle lanes can reduce bicycle crashes by 36%.
These strategies are generally compatible with other signalized intersection safety strategies.
Improvements to pedestrian facilities are discussed in detail in NCHRP Report 500: Volume 10. More details on design of sidewalks and walkways, including curb ramps, may be found in the FHWA report Designing Sidewalks and Trails for Access, parts 1 and 2. This report is available at the FHWA Safety page.
Additional details are available at safety.transportation.org.
This article is a reprint from the Federal Highway Administration's Intersection Safety Strategies Brochure. This Strategy is categorized as Strategy B3: Improve Geometry of Pedestrian and Bicycle Facilities, and it is adapted from NCHRP Report 500 / Volume 12: A Guide for Reducing Collisions at Signalized Intersections.
© 2009 Regents of the University of California
Tech Transfer Newsletter www.techtransfer.berkeley.edu/newsletter/08-4_09-1/strategy.php