At the April, 2005 ENTERPRISE meeting, members discussed the fact that rural intersection collisions were a known problem in rural areas of member states. This project was based on the following points:
- A solution was implemented in European countries with great success for reducing collisions by using an advisory speed limit sign to caution travelers when they approach a cross street with a vehicle waiting;
- The solution offered a low cost approach, and a five year test of 18 locations was currently underway overseas;
- The intent of this project was to help break down any barriers that might have prevented this approach from being deployed widespread across the United States by understanding the benefits and costs, as measured overseas;
- Once the benefits and costs were understood, this project funded outreach and education of this approach and delivered useful marketing material to support ENTERPRISE member states at promoting it within their jurisdiction;
- Finally, this project attempted to demonstrate this approach in a real-world (North America) deployment location. This demonstration was a small (1-2 sites) limited deployment. However, the preferred Phase 2 for this project was a larger scale deployment where ENTERPRISE funds were leveraged against funds from an outside source. Michigan believed that with sufficient cost/benefit justification (gathered in Phase 1) that MDOT safety funding during FY 2006 was available to add to the ENTERPRISE funding for a large scale deployment that proved to be a very adequate demonstration of the technologies and remain in operation within Michigan .
Intersection crashes account for almost 44% of total vehicle crashes in the United States . According g to a University of North Carolina study, there are approximately three million intersection-related crashes and 8,500 fatalities at intersections each year. Intersection collision avoidance is particularly important in rural, non-signalized intersections, since 85% of fatal intersection crashes occur at junctions without signals. The primary reported causes for intersection collisions include misjudgment of the situation, failure to correctly observe the situation, and inability to accurately perceive the degree of dan g er at the intersection. These factors should be taken into account in order to develop a successful collision avoidance system.
Several European countries developed and implemented successful intersection collision avoidance measures, including the United Kin g dom and Finland . The Swedish National Road Administration (SNRA) launched a five year trial project on variable speed limits. This involved equipping 18 non-signalized intersections with sensors at the cross-street to detect vehicles. Upon detection of an approaching vehicle, signs were illuminated on the main route to recommend or enforce a temporary speed reduction. This method was proven to provide an easy, low-cost solution for reducing the number of intersection-related crashes.
Although an intersection collision avoidance system was successfully implemented and was proven to reduce intersection-related crashes in parts of Europe, the approach had yet to be deployed in North America .
The primary goal of this project was to investigate the applicability of the European method of intersection collision avoidance and to help ease the deployment of this solution within North America. The scope of this project was to first gather information on the collision avoidance methods that were successfully employed in Europe, and to document the proven benefits and costs (cost benefit ratio) of these approaches. The intent of this was to develop a ‘Toolbox’ description of this approach that described each aspect of the approach as well as the anticipated benefits. This phase of the project performed outreach and technology transfer information sharing to transportation professionals (such as statewide traffic engineers and other key decision makers). An outreach plan was developed to perform the coordinated outreach activities, and included presentations at key conferences (e.g. the Rural ITS Conference, ITE, AASHTO) as well as briefings made to one or more representatives within ENTERPRISE member states.
The next phase of the project involved developing and deploying the proposed collision avoidance system at a trial location(s) in order to test the effectiveness of the solution. The test ran over a twelve month period, to allow statistics to be gathered during all weather conditions. A radar was set up after the warning signs to establish the extent to which drivers heeded the warnings.
A final report was written to explain the findings of both the research and deployment. This served as a “best practices” document and as such a manual for DOT’s to reference when considering collision avoidance solutions.
This project proposed two sequential Phases.
Phase 1: Technology Transfer and Information outreach
Task 1 included performing research on the current collision avoidance system that had been successfully deployed in Europe and established the most effective approach to adapt them for use in North America, together with a ‘Toolbox’ description of the approach. Some potential issues that were addressed included determining and addressing the reasons why this system had not already been implemented the United States, finding and addressing any negative effects the proposed solution had on drivers including increased driver distraction, and ensuring the proposed solution fit within established AASHTO guidelines. Any information describing the cost/benefit relationship for this deployment was documented as that was a key decision point for the use of safety funds in the U.S.
Phase 1 included the preparation of outreach material and budgets for presenting the solution at various conferences or technical meetings. The overall goal of Phase 1 was to educate key decisions makers (e.g. traffic engineers) on the steps to deployment and potential benefits of such a solution.
Phase 1 included a Final Report summarizing the results of the research and the information sharing activities. A portion of the deliverable was presentation material that may be reused by other members to present the approach and benefits of the solution.
Phase 2: Trial Deployment of the Collision Avoidance System
Phase 2 aimed to take the recommendations provided in Phase 1 and deploy the proposed intersection collision avoidance system at one or more trial locations in member states. The ideal scenario was that the results of Phase 1 would provide sufficient evidence of the benefit/cost relationship of this solution so that the ENTERPRISE funds set aside for the Phase 2 trial could be leveraged against additional funds from an outside source. One of two approaches was likely for Phase 2 of this project:
- If no outside funding from other agencies was assembled, a limited deployment of 1-2 sites provided evidence of the ease of deployment of the system coupled with the low-cost and potentially high-return associated with the reduction in intersection-related crashes.
- If sufficient cost/benefit support was gathered from previous trials in Europe to support a request for additional safety related funds, the ideal scenario would be the creation of a large scale deployment for Phase 2 of the project.