Accident Characteristics at Construction and Maintenance Zones in Urban Areas

About the report:

Work zone safety is currently a major concern to transportation and highway engineers because of the relatively higher rates of accidents in these areas. There is a strong indication that during the next decade, emphasis will be placed on maintenance and rehabilitation of the nation's highways rather than on the construction of new highways. This will result in many more work zones. Unless effective measures are taken to increase safety in these work zones, a significant increase in accident rates will occur. This national phenomenon is also currently being observed in Virginia, where data have indicated that total and fatal accidents are over-represented in urban work zones. A clear understanding of work zone accident characteristics and traffic control devices is however needed to facilitate the development of effective guidelines that will significantly improve safety at urban work zones. Therefore, the Virginia Transportation Research Council undertook a study to determine accident characteristics at urban work zones and to evaluate the effectiveness of traffic control devices in reducing accident rates. All of the sites considered were within urban areas and have no access control; average speeds were between 25 and 48 mph. The traffic control devices evaluated do not include warning signs placed some distance ahead to inform motorists of the approaching work zones. The results indicate that the major influencing factor on accident rates during the construction period on urban multilane highways is the accident rate just prior to the construction period. Also, the use of appropriate traffic control devices has a positive effect on safety in urban work zones, but the effectiveness depends on the type of traffic control used. The results also show that the most effective combination on multilane highways consists of flashing arrows, a flagger, and cones. On two-lane highways, flagmen and either cones, barricades, or static signs are most effective. Any combination not including flagmen, is less effective on two-lane highways than one including flagmen.

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