Safety at roadworks.

Two major studies have been completed by the Transport and Road Research Laboratory. The first updates an examination of the safety performance of major motorway roadworks. The second reviews for the first time, the risk associated with works on all-purpose roads. The safety of traffic management systems at major roadworks on motorways is monitored at intervals by the Transport and Road Research Laboratory. Developments in maintenance layouts and operation in recent years prompted a new review. The survey covered dual 3 lane motorways in several Counties. A sample of 17 roadwork sites was examined, representing a cross section of major maintenance layouts. Over 63 million vehicle passages totalling 1000 million vehicle kilometres of travel were recorded at the work sites and similar numbers at the same sites when no works were in progress. Taking all traffic management layouts together over the whole site (ie, the three main elements - approach, contra-flow and after sections combined) personal injury accident rates at roadworks are 1.6 times the no-works rate. The risk associated with each of the three sections through the works are identified, and compared with previous studies. The full range of accident characteristics (eg, by time, weather effects, accident type etc) are also examined. The study showed that the layouts in current use at major roadworks on motorways are still considerably safer than all-purpose roads without works. In contrast to motorway works, little was known about the effect that roadworks situated on all-purpose roads might have on accident rates. To fill this omission, a three year study was undertaken by TRRL in two Counties. Information was obtained from 155 roadworks, the majority of which were on Trunk and A class single carriageway roads. In spite of the duration of the study, and observations relating to about 100 million vehicle kilometres of travel through the works, only 34 personal injury accidents were recorded. A result, which highlights the difficulty associated with detailed safety studies of this nature, in contrast to similar motorway reviews. However, statistically significant results were obtained, which permitted the increase in accident risk due to roadworks on single carriageway all-purpose roads to be identified.