UPDATE: Wednesday, February 24th, 2016
The Fredonyer Pass Icy Curve Warning System (ICWS) is a Caltrans project designed to increase motorist vigilance and to reduce the number of crashes occurring when pavement conditions are icy. Using a combination of pavement sensors, RWIS data, and dynamically activated signage, the ICWS alerts motorists of icy conditions on the Fredonyer Pass in real-time. The dynamic warning system allows drivers to adjust their speed in preparation for road conditions further ahead, which is expected to reduce crash rates along the curves of the Pass. The Caltrans CCTV images below show potentially icy road conditions on Fredonyer Summit.
For this safety/operations incubator project, the research team evaluated the effectiveness of the Fredonyer ICWS with a focus on speed reduction under various conditions and safety performance through crash reduction. The study’s results suggest that the warning system is working as intended, with an average decrease in motorist speeds and a resulting 15% reduction in annual crash rates while operational. Additionally, the results indicated that the ICWS reduced crash severity as well. Since its full deployment in 2008, the system was estimated to have provided $1.03 million dollars of safety benefit per winter season through the reduction in crash frequency and severity.
Detailed results, conclusions, and recommendations from the project can be found in the final report document – Evaluation of the Fredonyer Pass Icy Curve Warning System. The report can also be downloaded from the COATS Phase 6 Documents page and the WSRTC’s document archive. This evaluation and other documents related to the COATS project can be found on the COATS documents page.