This interim report presents the broad concept for an adaptive traffic signaling system for work zones based on a distributed system of traffic speed sensors and traffic signaling devices. Both the sensors and the signals are seen primarily as rather simple, inexpensive, short-range devices deployed in substantial numbers at the work zone in the form of "smart barrels". Such barrels would nominally have the appearance of today's common, work-zone traffic-control barrels. Each barrel would communicate with "supervisory" computers that would process the distributed speed measurements and dispense commands for appropriately adjusted and distributed signaling based on existing speed differentials. The system is intended to be readily deployable, requiring little more effort than currently needed to set up today's systems of traffic control devices at work zones. The document discusses what is seen as probably the most challenging technical problem of such a system, a sufficiently inexpensive, but technically capable traffic speed sensor. In successive sections, the document reviews detector requirements, existing detection technologies, technologies selected for evaluation, and a plan for prototype testing and evaluation. A bibliography of technical and commercial references on sensor technologies is included. Concepts for the signaling devices are discussed in the companion interim report by John Sullivan, Work Zone Safety ITS: Human Factors Analysis And Pilot Research Proposal, UMTRI, May 2004. (Author/publisher)
Samenvatting