The Houston high-occupancy-vehicle (HOV) lane system is evaluated through calendar year 1988. Locally, these HOV lanes are referred to as transitways. These facilities are being built primarily as a means to help cope with the congestion problems in the Houston area. By the end of 1988, 36.6 mi of transitways were in operation on four Houston freeways. Transitways are generally located in the median of the freeway, are 20 ft wide, are reversible, and are separated from the freeway mixed-flow lanes by concrete median barriers. Ultimately, 95.5 mi of transitways will be constructed at a cost approaching $700 million. Surveys indicate that development of these transitways has public support. The primary objective of the Houston transitways is assumed to be to increase, in a cost-effective manner, the person-movement capacity of a freeway and to do it in a manner that does not unduly affect the operation of the freeway's general-purpose mixed-flow lanes. Transitway design and operation in Houston have not unduly impacted the general-purpose freeway lanes. Data indicate that the transitways can significantly increase peak-period person movement and average vehicle occupancy. New bus riders and carpools are generated by the facilities. For a transitway with a Houston-type design to be successful and cost-effective, it may need to offer a peak-hour travel time savings of at least 6 to 8 min compared with operation in the freeway mixed-flow lanes. The transitway also needs to move over 10,000 person-trips per day.
Abstract