Narrows Oversize Vehicle Identification System - Showcase Evaluation #13

This evaluation will compare oversize vehicle detection systems, assess their effectiveness, and provide recommendations for an integrated detection and traveler information system to improve safety in the Narrows Corridor of northern California.

One challenge with rural travel is natural features that impose constraints for highway design. This results in roadways that are built with less geometric tolerance than roads constructed in flat areas and therefore smaller lane widths, minimal or no shoulders, and tight radius curves. These constraints increase the possibility of sideswipe accidents and oversize vehicles becoming physically stuck in these areas. Due to the cost of traditional solutions like reconstruction, intelligent transportation systems (ITS) may be an attractive and cost-effective method of improving safety at these locations. US Route 199 in Del Norte County, California has a high rate of oversize vehicles that continue through the Narrows Corridor, violating their permit. This results in a high rate of sideswipe accidents and the occasional truck being stuck in this area. To improve the safety in this area, the California Department of Transportation (Caltrans) and WTI are working together to implement an integrated system that includes oversize vehicle detection, traveler information, and enforcement. The system is being developed using a multi-phase approach. Phase 1 included the installation of Changeable Message Signs (CMS) with static messages in the Narrows Corridor to enhance driver awareness of the potential for vehicle conflicts. Phase 2 of this project is to evaluate different detection technologies to determine their effectiveness in detecting overlength and width vehicles. After a detection technology has been selected, Phase 3 will begin. Phase 3 involves the design of a system for the Narrows Corridor called the Narrows Oversize Vehicle Identification System (NOVIS) that includes detection, traveler information and enforcement. Phase 4 would be an extension to a regional system along U.S. 199 from Grants Pass to Crescent City.This project will assist Caltrans in deploying and evaluating Phases 1 through 3, and will provide recommendations for a potential Phase 4 (not funded through this project). Data that will be used to support conclusions include accident data, speed data, motorist surveys, and a technology assessment.