Colorado, United States
A dynamic truck downhill speed warning system (DSWS) costing $180,000 to $200,000 was installed on I-70 in Colorado in 1993. The system used weigh-in-motion (WIM) sensor information to calculate maximum safe descent speeds for trucks, and then posted this information on a dynamic message sign (DMS) to alert drivers as they approached. ]
After the system was installed there was a 13 percent decrease in the number of accidents and a 24 percent reduction in the use of truck runaway ramps (from 1995 - 1997) in the area.