Road Management & Engineering Journal
Road Management & Engineering Journal
Copyright © 1999 by TranSafety, Inc.
May 1999
TranSafety, Inc.
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Fax: (360) 335-6402

Work Zone Accident Data--Substantial Improvements Needed
Editorial comments by Roy W. Anderson, P.E.

Originally published in the February 1989 TranSafety Reporter

(This article on work zone safety is reproduced from the February 1989 (Volume VII, No. 2) issue of the TranSafety Reporter, published and edited by Roy W. Anderson, P.E. To find legal summaries of cases related to highway work zones, please check on-line editions of "Road Injury Prevention and Litigation Journal" at this web site.)

Current methods for obtaining construction zone accident data are totally inadequate. Lack of reasonably accurate accident information obtained from police and public agencies responsible for work zone safety is evidence that, for the most part, these agencies are not doing their mandated job. For years 500 worker deaths per year in work zone traffic accidents was the number relied upon. The Transportation Research Board's SHRP research program used that figure to establish a research program priority. We recently reported that figure and received a call from FHWA that the 500 was greatly overblown. The best figure FHWA could come up with was approximately 60 for all worker deaths in highway construction, including non-traffic related deaths as reported by the Department of Labor. This discrepancy is unacceptable.

Many police accident reports have little more than the date of the accident, the driver's identity, injuries, and vehicles involved. Some states have a box to check to indicate construction at the accident site, but even this does not guarantee accuracy, nor does it provide details that would be necessary to analyze accident causes. Accident report forms should provide information that indicates the presence of a work zone; the nature of the accident; and information on the roadway environment (including measurements on such elements as edge dropoffs). This information would make it possible to analyze and draw substantially improved conclusions about work zone safety. An analysis could be made concerning the number of accidents and the major causes, comparing roadwork contribution to accident causation. Unfortunately, there is no consistent reporting system for accidents in work zones.

New Mexico Study of Construction Zone Accidents

A research paper presented by J.W. Hall and V.M. Lorenz at the 1989 Transportation Research Board meeting reflects the problem as seen in one state, New Mexico. The study emphasized the problems in construction zone accident reporting, and a general lack of adequate information about construction zone safety. The authors note that highway construction has shifted from new roads to reconstructing existing roads. They further observe that this creates more room for problems between drivers and construction workers and/or construction equipment, in other words, more room for accidents. In order to "identify factors that can maintain or improve the safety of a roadway section that is under construction," Hall and Lorenz examined construction zone accidents on New Mexico rural highways between 1983 and 1985.

After selecting specific construction project locations, the authors dug beyond the usual reporting system and:

This study showed that the current accident reporting system is severely flawed. Hundreds of accidents in their sites were not recorded as construction zone related accidents on the accident reports. Also, when the data from the accident reports were transferred to the computer, a significant number of accidents were improperly coded to indicate a construction zone which, in fact, did not exist. This study also showed that accidents increased by 26 percent during construction (with Interstate Highways showing the most significant increase--33 percent). Further, the record keeping system "seriously and systematically underestimates the incidence of these zone accidents," and there is indeed a construction zone accident problem.

No recommendation was offered to counteract specific construction zone accident types (for example, ran off the road, sideswipe, overturn, etc.) because the study did not find significant differences between accident types before and during construction. The study did note that "certain accident characteristics may be overrepresented in construction zone accidents," such as rear-end collisions and multiple vehicle accidents. The study found there was no significant change in pedestrian accidents, despite construction workers being present.

The authors discussed the importance of on-site inspections at construction zones which can help identify possible hazards and prevent construction zone accidents. They noted that records of such inspections conducted in New Mexico indicate that problems related to the proper application of traffic control devices are cited most frequently as the root cause of construction zone accidents. But, they state that this could be because these kinds of problems might be the easiest to note at the site, and the standards for traffic control are well established.

Hall and Lorenz concluded that the "frequency of accidents in construction zones is substantially greater than indicated by the accident record system. With the continued emphasis on roadway reconstruction, it is expected that this situation will not improve unless positive steps are taken. The existing records do not provide a definitive answer to the role of engineering in the occurrence of construction zone accidents."


It is critical that construction zone accidents be studied more closely. As evidenced by the New Mexico study, even when states have a reporting system for accidents related to work zones, the system is far from adequate. The reports may be filled out or coded incorrectly. Also, it is not always readily evident that work is being performed in the area if the work was being performed by a utility company, or involves moving or mobile operations. The police must be motivated to do a more thorough accident investigation. A substantial training effort will have to be made to train police on how to identify work zones and how to report the important factors.

While some research has shown the same basic flaws as the New Mexico study, current research shows that the problem of grossly inadequate data has not yet created sufficient concern to support a needed change in the attitude that now hampers any improvement.

Copyright © 1999 by TranSafety, Inc.

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