Transitways

As metropolitan areas throughout the nation grapple with mounting concerns over traffic congestion, poor air quality, and fossil-fuel dependence, policy makers often turn to public transportation for solutions. Particularly within the context of fiscal limitations, the “transitway” concept is seen as an attractive and cost-effective strategy for improving transit efficiency and alleviating congestion in major travel corridors.

In general, a transitway is an exclusive, limited-access roadway or a travel lane or lanes of a roadway—also called a dedicated right-of-way (ROW)—reserved for public transit. The transitway includes associated infrastructure, such as stations, transit terminals, and park-and-ride lots. Transitways may also be referred to as busways, bus/carpool lanes, high-occupancy-vehicle (HOV) lanes, or commuter lanes, or transit lanes, T2 lanes, or T3 lanes in Australia. Transitways are most frequently associated with buses and trolleys.

Bus rapid transit (BRT) systems often use transitways for the long-haul portion of travel. In some situations, emergency vehicles, taxis, and high occupancy vehicles such as carpools and vans may be authorized to use transitway facilities.

Transitways are a special category of roadway designed to provide faster operating speeds, better trip-time reliability, and an overall higher level of transit service than what is typically provided on arterial streets. When properly implemented, transitways have the potential to maximize the person-moving versus the vehicle-moving capacity of the roadway. This article defines transitways, describes their overall characteristics, and provides an overview of benefits and drawbacks.

The term transitway appears to have originated in the Ottawa region of Ontario, Canada, where Ottawa-Carleton Regional Transit Commission (OC Transpo) launched its “Transitway” in 1983. One of the most extensive and successful transitway implementations in North America, OC Transpo's Transitway serves as the backbone of the rapid transit system for the Canadian capital area.

Transitway facilities have been implemented in locations throughout North America, including Pittsburgh, Pennsylvania; Washington, D.C.; the Lincoln Tunnel between New Jersey and New York City; Los Angeles and San Francisco, California; Boston, Massachusetts; Miami, Florida; Houston, Texas; Seattle, Washington; Cleveland, Ohio; and Eugene, Oregon. Transitways can also be found in Bogotá, Colombia, and in Brisbane and Adelaide, Australia.

Transitways in the United States are typically implemented by a state department of transportation (DOT), and can assume a variety of configurations and operating arrangements, from simple provisional lanes to fully grade-separated facilities. Physically segregated transitways include at-grade or grade-separated roadways or lanes developed within a separate ROW, barrier- or buffer-separated roadways developed within the freeway ROW, exclusive facilities developed in the median of an urban street, and arterial bus streets and bus tunnels.

In some situations, freeway, arterial, or shoulder lanes that are not physically separated from other traffic lanes function as transitways. These lanes may be concurrent flow lanes, which are lanes in the peak direction of traffic flow, or contra-flow lanes, which are lanes taken from the nonpeak direction to provide additional lanes for the peak-flow direction.

Transitways may provide further time savings by means of additional transit priority measures, such as bus signal priority and queue jumps. Signal priority for traffic lights uses specialized signal phasing to provide extra time for buses to move through intersections. Queue jumps allow buses to bypass traffic backups at ramp meters, toll plazas, and intersections. Different types of transitway facilities vary in the travel time savings they provide and therefore have different levels of effectiveness.

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