Vehicle guidance in road-work zones

Work zones represent a discontinuity for drivers in terms of driving speed and roadway characteristics. Therefore it is generally accepted that special demands must be made on the traffic devices used in these areas. This paper presents a functional description of delineation systems used in work zones. Based on a theoretical analysis predictions are made about the effectiveness of particular delineation systems to serve as a reference in course perception. Furthermore a short overview is given of some research which was carried out about a second function of the delineators, i.e. to give the driver adequate information about the geometry of the road ahead. Visibility requirements are derived for this function. A laboratory experiment is also discussed, in which the effectiveness of a number of delineation systems as a means of preview guidance was investigated. It is concluded that delineators which are mounted at eye height function poorly and that improvements can be reached by lowering the delineation. In addition, it is concluded that the use of a chevron configuration on panels may be particularly effective in conditions where panels are placed somewhat haphazardly or when only a limited number of panels is used.
This paper presents a functional description of delineation systems used in work zones. Based on a theoretical analysis predictions are made about the effectiveness of particular delineation systems to serve as a reference in course perception. Furthermore a short overview is given of some research concerning a second function of the delineators, i. e. to give the driver adequate information about the geometry of the road ahead. Visibility requirements are derived for this function. A laboratory experiment is also discussed, in which the effectiveness of a number of delineation systems as a means of preview guidance was investigated. Refs.