speed

85th percentile speed limits: “Fast, Furious & Fatal”

By Eric Sundquist In 2017, when the City of Los Angeles reviewed operating speeds across its system, it ended up raising speed limits on 89 miles of roadway. Why would a city with a Vision Zero goal raise speed limits in corridors with a history of crashes? Because of a California statute that

Lowering speed limits can reduce crashes

By Chris McCahill Speed limits are often based on observed 85th percentile free flow speeds. Setting them lower, even to address safety concerns, can be difficult once engineering recommendations have been made. A new study, however, bolsters the case for doing so by showing that setting limits

Toward livable streets: A review of recent improvements in practice

By Eric Sundquist In the last decade a number of project development and design guides, such as ITE’s “Designing Walkable Urban Thoroughfares,”  NACTO’s “Urban Street Design Guide,” and city design guide manuals, have emerged. A new article by Eric Dumbaugh of Florida Atlantic

Speeding is akin to an addiction, and roadway design can be an effective treatment

By Eric Sundquist Gerry Forbes, author of the Transportation Association of Canada’s excellent and too-little-known “Speed Management Guide,” suggests in a new ITE Journal article that speeding has some attributes of an addiction. He compares speeding and several addictive substances on

International review confirms speed management is critical to road safety

By Chris McCahill Speed reductions can lower crash risks significantly, confirms a new report by the International Transport Forum, an intergovernmental organization of 59 member countries including the U.S. The research report, Speed and Crash Risk, looks at 11 case studies in 10 different

Report calls for a Safe Systems approach to reduce fatalities

By Robbie Webber A new report from the World Research Institute finds that the most effective way to prevent traffic deaths is a systemic approach that shifts responsibility away from the drivers and other road users to those responsible for roadway planning and designing, land use mix, providing

Florida is leading the nation in lowering speeds to reduce crashes; will other states follow?

By Rayla Bellis Note: This post has been changed to correct erroneous information from another source. The original post stated that speed limits would be changed. FDOT plans to change the design of some roads to encourage slower driving, but not the speed limit on existing roads. The Florida

More evidence that wider roads encourage speeding

By Chris McCahill Wider lanes and shoulders encourage faster driving, according to a new study published in the Journal of Transportation Engineering. Researchers from Texas A&M studied uncongested freeways in Dallas, Houston, and San Antonio. Based on more than 650,000 observations, they

Are higher highway speed limits worth it?

By Bill Holloway A recent study indicates that raising speed limits on non-limited access highways from 55 to 65 miles per hour is likely to have a negative benefit-cost ratio when crash injury and fatality costs are fully accounted for. The analysis, which focused on non-limited access highways