A 5-mi-long contraflow lane is being constructed on east r.L. Thornton freeway (ih-30) in dallas, texas. This is a joint project of the texas highway department and dallas area rapid transit. The lane will provide high-occupancy vehicles (hovs) a travel time savings of up to 10 min compared with traffic operating in the congested mainlanes. This priority treatment project is unique because it uses a movable concrete barrier system in the design and operation of the contraflow lane. The movable barrier system, which consists of a barrier transfer vehicle and a continuous concrete barrier, will providegreater safety by physically separating hovs from the opposing traffic in the general-purpose lanes. Although contraflow lanes have traditonally been restricted to buses and authorized vanpools for safety reasons, this relatively new technology will permit carpools to safely use the lane as well. The decision to use the movable barrier system instead of pylons to designate the priority lane essentially doubled the capital and operating costs of the project; however, the carpool demand also doubled the number of passenger-hours of travel time saved. The greater safety, attraction of carpools, greater perception of utilization, and ability to move more people in the peak period made the barrier system an attractive demonstration project. This paper discusses design and operational issues associated with using the movable barrier system for a contraflow hov lane. Elements requiring special attention were the access locations design, barrierend treatment, equipment storage and maintenance, set-up and take-down techniques, and enforcement procedures. This paper appears in transportation research record no. 1299, Hov facilities and transportation systems management 1991 .
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