8 Work Zone Safety
8.5 Target Crash Population
Dynamic Speed Advisory systems such as the Minnesota system and ADAPTIRTM target the population of crashes that happen in work zones.
Using a FARS query2, the manner of collision by work zone type was examined. From Table 7, it can be seen that only 382 or about 2% of rural fatal crashes occurred in work zones. While this proportion is relatively small, work zone operations and safety are a focus area of FHWA and are highly visible to the traveling public. Variable speed limit systems should have the highest payoffs in work zones that have heavy traffic. The system being tested in Minnesota is good for the traveling public, as it allows them to travel at normal speeds when workers are not present.
The other highlighted systems target the same population of crashes as the dynamic speed advisory systems. The highlighted systems all strive to warn drivers that they are approaching work zones and need to adjust their driving behavior accordingly. They hold their maximum potential for reducing crashes in work zones with heavy traffic, large speed differentials, heavy truck traffic and areas where radar detectors are legal and are commonly used.
 Table 7: Manner of Collision by work Zone Type - 1998 Rural Fatal Crashes |