Improved Temporary Traffic Control Guidelines for Urban Freeway Interchanges

Author/Presenter: Ullman, Gerald L.; Finley, Melisa D.; Knapp, Keith K.; Pike, Adam M.; Songchitruksa, Praprut; Williams, Alicia A.
Abstract:

Evidence exists to suggest that drivers often have difficulty in navigating through work zones that occur within the vicinity of complex urban freeway interchanges. The numerous existing guide signs, presence of short auxiliary lane segments, multiple lane exits, high merging traffic, and other conditions in the work zones present complex driving situations and place considerable work load on drivers. Driver work load and driving complexity increases even more when temporary travel paths configured with channelizing devices are in conflict with existing guide signs. It is often difficult to convey lane closure, travel paths, and other warning information using traditional temporary traffic control signs and temporary pavement markings. These difficulties are experienced at both long-term construction and short-term maintenance activities. Meanwhile, selection and maintenance of pavement markings can be very difficult in long-term construction work zones. A pavement marking selected for a given project may not be durable enough to provide motorists adequate delineation through an interchange during the entire time it is in place. Conversely, a marking product may be difficult to remove completely in other applications, which can potentially confuse drivers attempting to traverse the work zone after a major traffic switch.

Both cases can lead to driver confusion and safety/operational problems through the work zone. Because of these concerns, objectives of this research project are the following: (1) improve temporary traffic control (TTC) guidelines to improve motorist path guidance and way-finding through urban freeway interchange areas; and (2) improve guidance on selecting appropriate pavement marking materials in work zones.