Road Weather Management > Traffic Control - Control Strategies > Variable Speed Limits
In Finland, a benefit-cost analysis supported the deployment of weather information controlled variable speed limits on highly trafficked road segments.(25 March 2006)
In Salt Lake City, Utah the ADVISE fog warning system tested on a two-mile section of I-215 promoted more uniform traffic flow, reducing vehicle speed variability by 22 percent while speeds increased 11 percent.(June 2003)
A study of travelers on Snoqualmie Pass, WA found that DMS can decrease mean driving speeds and reduce accident severity.(December 2001)
In Tennessee, a fog detection and warning system implemented in 1994 significantly improved safety as no fog-related accidents have occurred since implementation.(October 2000)
In Finland, road weather information posted on dynamic message signs was well perceived and remembered by surveyed drivers; 90 percent deemed variable speed limit signs useful.(December 1995)
In Finland, a road weather information system with variable speed limit signs was projected to decrease the average vehicle speed by 0.4 to 1.4 percent and reduce the annual crash rate by 8 to 25 percent.(December 1995)
In Finland, a road weather information system with variable speed limit signs was projected to yield a benefit-to-cost ratio ranging from 0.6:1 to 1.6:1 depending on the influence of the system on vehicle speeds and crash rate.(December 1995)
On the A16 Motorway in the Netherlands, an automatic fog warning system prompted drivers to slow down by 8 to 10 km/hr and drive at more uniform speeds; however, during extremely foggy conditions the system increased the average vehicle speed by 31 km/hr matching the recommended speed.(1995)
In Finland, the average implementation cost for a weather responsive roadside VSL system on a dual carriageway was estimated at 80,000€; average maintenance costs (including replacement costs) were estimated at 3,500 €/km/year. (25 March 2006)
A variable speed limit system consisting of multiple ITS components and covering 40 miles over the Snoqualmie Pass in Washington was designed and implemented for $5 million.(November 2001)
Minimize problems in creating contractual arrangements for testing a new ITS technology by creating negotiating benchmarks, designing a partnership arrangement, and developing a separate procurement process for different technological components. (3/1/1999)
Carefully select a project manager to be responsible for deployment and testing of new ITS technology.(3/1/1999)
Anticipate challenges with the ITS technology being tested, including problems with software modification and adaptation of previously developed technology.(3/1/1999)
