Variable speed limits effective along Virginia’s foggy highways

Fog can create deadly driving conditions, particularly in mountainous areas. Fog along the 12-mile stretch of highway in Virginia has led to hundreds of crashed vehicles and several deaths over the last couple of decades. In 2016, VDOT launched a system of weather sensors, variable speed limits (VSLs), and dynamic message signs (DMS) meant to slow down drivers during unsafe conditions. This system lowered speeds by an additional 2 to 5 mph, on average, and the number of fog-related crashes seems to have dropped by more than 50 percent. VDOT will continue to monitor the corridor, but the Virginia Transportation Research Council says similar systems should be effective for more widespread use.

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

A study by UCLA examines the use of the 85th percentile to set speed limits, including a California law that gives little flexibility to local jurisdictions. The principal author argues that the 85th percentile is not a good standard of safety. She cites an “injury minimization” scheme, and recommends that local governments be freed from the current standard in order to pursue these safer limits.

Lowering speed limits can reduce crashes

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 just below the observed speeds can reduce crashes, including the most serious ones.

Lowering speed limits can reduce crashes

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 just below the observed speeds can reduce crashes, including the most serious ones.

Toward livable streets: A review of recent improvements in practice

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 University and Michael King of BuroHappold Engineering, reviews these updated practices. The article finds four general principles of livable streets engineering.

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

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 dependence and harm, suggesting speeding is right up there with cocaine and heroin. Probably more interesting than this provocative framing is the remedy Forbes suggests. He rejects the idea that speed management is simply a matter for law enforcement.

International review confirms speed management is critical to road safety

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 looks at 11 case studies in 10 different countries around the world. In every case, speed increases were associated with more crashes and more severe injuries, while speed decreases were associated with fewer crashes, injuries, and deaths. The relationships, however, are not linear.

Report calls for a Safe Systems approach to reduce fatalities

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 mobility options, and enforcement of traffic laws. Analysis in 53 countries found that those that have taken a “Safe System” approach have achieved both the lowest rates of fatalities per 100,000 inhabitants and the greatest reduction in fatality levels over the past 20 years.

Report calls for a Safe Systems approach to reduce fatalities

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 mobility options, and enforcement of traffic laws. Analysis in 53 countries found that those that have taken a “Safe System” approach have achieved both the lowest rates of fatalities per 100,000 inhabitants and the greatest reduction in fatality levels over the past 20 years.

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

The Florida Department of Transportation plans to lower design speeds in some urban areas to 25-30 mph to improve roadway safety. This makes FDOT one of the first states to tackle head-on the safety impacts of vehicle speeds. Speed is one of the most significant factors in roadway crashes and fatalities in the U.S., and an especially serious problem for pedestrians and bicyclists.