AASHTO Journal, 27 July 2012
A new web-based tool from the Federal Highway Administration is helping traffic engineers set speed limits for specific segments of road.
USLIMITS2 was developed by FHWA’s Office of Safety to assist states and local governments in their efforts to reduce speeding-related fatalities and serious injuries.
While it can be used to set speed limits on all types of roads, ranging from rural local roads and residential streets to urban freeways, it is intended to be particularly helpful to local communities and agencies without ready access to engineers experienced in conducting speed limit studies. However, the tool also helps experienced engineers to have an objective second opinion and increase confidence in speed-setting decisions.
Those using the program input factors such as route type, section length, annual average daily traffic, 50th and 85th percentile speeds, statutory speed limit, and crash history. USLIMITS2 recommends a speed limit and shares a list of issues that the user may need to investigate.
The original USLIMITS was developed in 2006 as a National Cooperative Highway Research Project (NCHRP) product. FHWA then adopted the program with enhancements and pushed it forward with user/customer support on the FHWA server.
The USLIMITS2 tool is available online at bit.ly/USLIMITS2.