Improper flagging techniques and driver misunderstanding of flagger messages can compromise the effectiveness and safety of a flagger. supplemental devices may be necessary to complement the standard traffic control and flagging techniques outlined in the manual on uniform traffic control devices (mutcd) to ensure that drivers understand what actions are expected of them at work zones controlled by flaggers. The texas transportation institute recently evaluated a reusable, temporary stop bar and a freestanding, oversized stop/slow sign paddle at lane closures on two-lane, two-way highways where flaggers were used to alternate one-way traffic. Operational data on distances from the flagger at which vehicles stopped, speeds through the work zone, and approach speeds were analyzed. the data showed that the temprary stop bar and oversized paddle were useful in helping drivers decide when and where to stop in front of the flagger. However, the stop bar and sign paddle had no significant effect on reducing approach speeds or speeds through the work zone. The flaggers who actually used the supplemental devices commented that the oversized stop/slow paddle helped drivers respond to their commands better and that the temporary stop bar helped identify a point at which drivers were to stop. This paper appeared in transportation research record no. 1148, hazardous materials transportation, work-zone traffic control, and traffic marking materials. For covering abstract see irrd no 818401.
Abstract