5 Intersections
5.1.3 Target Crash Population
Queue Detection
The queue detection system in Oregon targets the population of rear-end crashes that occur on vertical curvature hillcrests. According to a FARS query,(2) only 33 fatal rear-end crashes occurred on rural roadways (for which road class is known) on hillcrests in 1998. However, this system should have more of an impact on non-fatal crashes. Such systems should provide the maximum potential payoff when applied to specific situations where queues frequently build up immediately over a hillcrest.
Unsignalized Intersections
The ICWS deployed in Virginia targets the population of crashes occurring at unsignalized intersections of major and minor roadways, where the traffic flow on the minor road is controlled by a stop sign. A FARS query was used to examine the manner of collision by traffic control device on rural non-Interstate Roadways. Table 4 shows that 1898 fatal crashes occurred at, or were related to, rural stop-controlled intersections. It should be noted, however, that this crash count would also include crashes occurring at, or related to, four-way-stop-controlled intersections.
 Table 4: Manner of collision by traffic control device for rural non-interstate roadways - 1998 intersection or intersection-related fatal crashes. |
This type of system holds the maximum potential payoff for intersections of major and minor rural roadways where there is limited sight distance and resistance to full signalization.