A Multi-Site Examination for the Impact of Changes in Posted Speed Limit on Traffic Safety
This study examined the effects of posted speed limit changes on traffic safety by conducting before-and-after assessments using crash and speed data from multiple sites.
July 2023 Research Brief
Protecting Roadside Workers: Field Evaluation of Flares, Cones, and Tow Truck Light Patterns
This report documents a study with three aims: evaluate the effectiveness of flares or cones in combination with two different tow truck lighting systems; survey workers regarding use of flares and cones; and document available and potential countermeasures.
January 2023 Technical Report | Report Summary
Protecting Roadside Workers: Field Evaluation of a Vehicle-Mounted Variable Message Sign and Examination of Worker Perceptions and Use of Countermeasures
This project assesses the effectiveness of a vehicle-mounted variable message sign in promoting safer behaviors in passing motorists. The study also examined workers’ perceptions and adoption or use of different countermeasures.
January 2023 Technical Report | Report Summary
Traffic Fatalities on Urban Roads and Streets in Relation to Speed Limits and Speeding, United States, 2010–2019
This research brief examines characteristics of traffic fatalities on urban roads and streets in relation to various factors, with an emphasis on the speed limits present at crash locations, as well as the role of speeding.
July 2022 Research Brief
Improving Roadside Responder Crash Data: Outcomes from an Expert Roundtable Discussion
This brief highlights a roundtable discussion that sought to identify ways to improve data about the safety of incident response and emergency services personnel working on the side of the road. Recommendations are made based on information provided by the panel of experts.
December 2021 Research Brief
Impact of Speeds on Drivers and Vehicles – Results from Crash Tests
This study examines how vehicle crashworthiness and occupant protection degrade as impact speeds increase. The results and implications in this report provide valuable information for those who advocate for safety considerations when setting maximum posted speed limits.
January 2021 Technical Report | Report Summary
Review of Current Practices for Setting Posted Speed Limits
The aim of this study is to investigate the current practice of how speed limits are set across the country and to understand how the process impacts the traffic environment and drivers’ behaviors.
April 2019 Research Brief
Safety Benefits of Highway Infrastructure Investments
This study estimates the reduction in serious injuries and deaths that could potentially be achieved through investment in proven cost-effective highway infrastructure safety measures, and the level of investment required to achieve those benefits.
May 2017 Technical Report | Report Summary
USRAP Pilot Program Phase III
This report details US Road Assessment Program pilot studies performed in Illinois, Kentucky, New Mexico, and Utah, and also presents the results of a validation study of the usRAP star rating protocol using data from Iowa and Washington.
May 2010 Technical Report
USRAP Pilot Program Phase II
Development of specialized risk maps that address safety issues of interest to the participating states, such as unbelted occupant, speed-related, alcohol-involved, roadway- and lane-departure, commercial-vehicle-involved, older driver, and young driver crashes.
January 2008 Technical Report