HOT DC PROSPECT: Shirley losing HOVs

The federal government’s greatest showpiece HOV facility, and its oldest, the Shirley Highway (I-395) in northern Virginia, is steadily losing custom and will soon be ripe for toll buy-in. Peakhour usage of the facility dropped almost 40 percent in the past two years according to statistics supplied to TR newsletter by Virginia DOT. And the opening of a new section of the Metro blue line to Springfield VA at the approaches to the Shirley, and associated discontinuation of bus service down the Shirley, are expected to drop HOV use by a further substantial chunk. If it were flowing at capacity in the 1980s it could be down to 30 or 40 percent of capacity shortly. At these levels the Shirley lanes would be carrying not only far fewer vehicles but also fewer persons per lane than the unrestricted lanes nearby. In any case it has already developed substantial spare capacity.

The Shirley is mostly a 3/2/3 highway leading out from DC via the 14th St bridges, past the Pentagon is the major artery southwestwards out of the national capital. (It was originally I-95 but with the abandonment of I-95 through NE DC and MD, the Shirley was renamed I-395 inside the Beltway.) The centrally located dual-lane reversible HOV is the victim of the continued powerful trend against multi-occupant travel throughout the country, compounded by staff downsizing at the Pentagon, the major destination for Shirley HOVers, plus two rail new options — long-distance Virginia Rail Express and the Metro. In 1991 the Shirley was carrying around 1400 vehicles/lane/hour in the peak hour and 9,000 persons. VDOT numbers show that in the spring of 1995 this was down to 1220 and 5,780 while by spring of 1997 it was 750 vehicles and 4,780 passengers.

Fairfax County transport director Shiva K Pant says there is simply too much transit service: “You have bus service, carpool lanes, commuter rail. There are only X number of people in the market for non-single occupant vehicles. With each additional investment you are competing for this same limited ridership.”

Transit hits HOV: The Metro transit staff have proposed routing a substantial number of the buses currently using the Shirley HOV to the new Springfield metro stop. If that happens on any scale passenger movement on the Shirley HOV lanes would fall below the 2,500 to 3,000 veh/ln/hr that is common on the unrestricted lanes, which will completely undermine the rationale for the HOV — the slogan for which has always been “Moving people, not vehicles.”

The Shirley is a 2-lane reversible opened in 1969 as the pioneer of a new kind of rideshare facility. It opened as 8km of 2-lane reversible busway, barrier-protected facility, with separate interchnage ramps, a motorway within a motorway. It was the first of its kind in the US and probably the world, the model for others in Seattle, Houston, Minneapolis, San Diego, Pittsburgh, Westchester Co NY and Charlotte NC. It was completed 18km to just beyond the Beltway from the 14th Street Potomac River bridges by 1975. Late 1973 it became an HOV4+ facility allowing vans and cabs and loaded autos as well as the buses. By Jan 89 the facility was opened to HOV3s and a variety of measures were used to extend interim striped HOV3 lanes some 8km southward to help feed it. After total reconstruction of I-95 south from the Beltway 30km to Dumfries Virginia, it was reopened as 3/2/3 like the Shirley inside the Beltway — the 2 being a similar barriered reversible with its own ramps. At its busiest end the extension is carrying 570 vehicles/lane/hr, a 23% rise on the ‘95 figure when the interim lanes were in operation but at its far end a pathetic 88 veh/ln/hr.

There are stirrings within VDOT, the Metro Washington Councils of Government, and Virginia counties to study toll buy-in before the gaps between vehicles get too embarrassing. In Virginia most of the $s for transit comes from cities and counties and they are likely to welcome the revenue which toll buy-in could generate.

Back of the envelope calculations suggest that outside the Beltway the facility could take an average 600v/ln/hr buy-ins and outside the Beltway 800v/ln/hr. Being an HOV3 facility the buy-ins could be HOV2s as on the Katy in Houston, maintaining the carpooling flavor. Or if they were really serious, a market-oriented administration would simply advertise an express toll franchise for the Shirley and enunicate the Gabriel Roth doctrine about HOV which says “So long as you toll by vehicle you automatically give that encouragement to HOVers since the laws of simple arithmetic will make the toll per occupant decline in proportion to the number of occupants.”

Maryland too: Over the other side of the Potomac, Maryland has I-270, another HOV concurrent and simply stripe-separated (except at the Beltway Spurs’ split in Rockville where wonderful soaring ramps allow HOVers to mate and split without having to weave across the regular lanes). It is HOV2 and it too is very lightly used, though it is early days and too early to make a big fuss about. It is designed to link with Maryland’s 67km of the Beltway (8-lanes now and 220k v/d) where a 4/1/1/4 configuration has been proposed as one option in a Major Investment Study (MIS), the pair of inner lanes being designated as “HOV/SOV toll” ($0.7b to $1.2b), the other major options being an improbable elevated transit line ($2.5b to $4b), and the others compulsory package of “transp demand management” techniques such as enhanced signage and traveler information which are likely to have minimal impact by themselves, though they are worthwhile in conjunction with enhanced capacity.

The motorway alternatives for the proposed Inter-County Connector are also laid out in their MIS as a toll facility (see TR#16 Jun 97 p8) so the Maryland suburbs of Washington could see an innovative toll express system developing if the political will were there, which it isn’t yet. The present big battle is over the ICC itself. (Contact Ron Kirby or Pat Zilliacus Metro Wash Council of Govts 202 962 3200)