HOV Facilities and Use

Northern Virginia boasts one of the country's most successful high occupancy vehicle (HOV) systems. More than 44,000 travelers choose to use one of Northern Virginia’s three HOV freeway corridors[6] for their morning commutes.  HOV lanes have become an integral part of the Washington Metropolitan region’s transit system. The program restricts certain highway lanes to exclusive use by multi-occupant vehicles at peak travel times to encourage carpooling, vanpooling and transit bus ridership. 

The bus-only lanes that opened on the Shirley Highway in 1969 were the first HOV lanes in the country.[7]  NVTC managed a major demonstration of express buses in this corridor. These lanes were then opened up to high occupancy private automobiles to promote more efficient fuel use in 1973. Construction of HOV lanes throughout the country progressed slowly in the 1970s and then began to pick-up in the mid-1980s to early 1990s. 

 High-occupancy vehicle facilities are designed to offer several advantages over conventional freeway lanes and roads. 
They can:

·        Increase the average number of persons per motor vehicle using a highway over conventional lanes;

·        Preserve the person-moving capacity of a lane as demands for transportation capacity increase;

·        Enhance bus transit operations;

·        Support air quality goals;

·        Serve a variety of employment centers in urban and suburban areas; and

·        Provide predictable travel times even during periods of high demand for highway capacity.

Currently, HOV lanes exist in four Northern Virginia corridors: the 27-mile Shirley Highway (I-395) I-95 corridor from Washington, DC to the south of the Beltway as far as Route 234 near Dumfries in Prince William County; the 27-mile I-66 corridor both inside and outside the Beltway from Rosslyn to Route 234 in Manassas; the 11-mile VA 267 (Dulles Toll Road), which has a concurrent-flow HOV lane between Route 28 near Dulles International Airport and the main toll plaza just west of Route 7; and Route 1 and VA 400 (Washington Street) through Old Town, Alexandria. These HOV lanes play a crucial role in the region’s transportation system. 

The success of Virginia’s HOV system is the result of substantial public and private investment in HOV lanes, park-and-ride lots, transit and car/vanpooling services, rideshare matching services, and popular “slug” opportunities—a form of casual carpooling.

Mode Share

As part of its core travel monitoring program, the National Capital Region Transportation Planning Board of the Metropolitan Washington Council of Governments (COG/TPB) conducts cordon studies that count the number of persons by travel mode. The last Metro Core Cordon Count was completed in 1999 while the latest Beltway Cordon count took place in 2001.  Figure 33 shows the counting stations for the Beltway and Metro Core Cordon study. Travel counts were conducted from 6:30 AM until 9:30 AM in order to capture the majority, but not all, commuter trips.

Figure 34 shows that when offered good HOV[8] infrastructure and transit service, less than half of all peak period commuters choose to drive alone.[9]  Figures 38 and 39 include the absolute numbers of commuters in the corridor as well the mode shares. The share of transit commuters increases closer to the urban core—a reflection of the greater degree of transit options.

Source:    1999 COG/TPB Metro Core Cordon Count, A.M. Peak Period.

Figure 39:  1999 Metro Core Cordon Count Mode Share
Summary for Major HOV Corridors
6:30 AM – 9:30 AM

Source:    1999 COG/TPB Metro Core Cordon Count, A.M. Peak Period.

Travel Time Savings

   As shown in Figures 40 and 41 one of the notable benefits of using Northern Virginia’s HOV facilities is the substantial reduction in travel time over non-HOV travel. The HOV lanes usually move at speeds approaching the speed limit, while the parallel conventional lanes move at much slower speeds due to congestion. Survey data show that morning commuters using the HOV lanes shave about one half-hour off their commute on I-95/I-395 and I-66 and about 20 minutes off their commute on the Dulles Toll Road in comparison to commuters in the parallel conventional lanes[J1] .  Furthermore, commute time is more predictable in each of the corridors for those who choose the HOV lanes.[10]

    A 1999 study by the COG/TPB showed that during the afternoon peak commute the average speed in the HOV lanes on I-95/I-395 between the Virginia end of the 14th Street Bridge and Joplin Road (VA 619) in Prince William County, a distance of about 27.3 miles, reached 60 mph.  In the parallel conventional lanes, it took commuters 133% longer to travel the same distance at an average speed of 26 mph.  In other words, commuters using the HOV lanes saved 36.5 minutes or 1.34 minutes per mile during their afternoon commute. The study also shows significant travel time savings in the HOV lanes on I-66 and the Dulles Toll Road (VA 267).

    The Texas Transportation Institute estimates that the average auto commuter in the Washington DC metropolitan area suffers 84 hours of peak period delay annually due to congestion on the region’s freeways and major roadways.[11] Using a different methodology than the COG/TPB HOV performance study, the TTI calculates mobility levels for specific HOV corridors. [12] The results show even greater time savings for commuters using the HOV lanes. Commuters on a 55-mile section of I-95/I-395 save over one hour, commuters on a 34-mile section of I-66 save more than 30 minutes, and those who choose the HOV lanes on the Dulles Toll Road save nearly one-half hour. Clearly, commuters who take advantage of the region’s HOV lanes by traveling in vanpools, carpools or on transit can save many hours annually from their commutes.

Source:       1999 Performance of Regional High-Occupancy Vehicle Facilities on Freeways in the Washington Region: An Analysis of Travel Times. Final Draft. National Capital Region Transportation Planning Board of the Metropolitan Washington Council of Governments (October 6, 2000).