VTA light rail has struggled -- and it's mostly because of the valley's sprawl, transportation experts and agency officials say.
(Kevin) Connolly (VTA's transportation planning manager) noted that the South Bay's first light-rail line was built along onion fields, where planners had expected homes and businesses to pop up along the route. That contrasted with the strategy in most other cities, which is to put light rail along existing, dense corridors. . .
"In our case we tried to graft a big-city transit type of mode onto a suburban environment, and it's still kind of a work in progress," Connolly said.
In a way, the South Bay experience is a real life illustration of the conundrum GMU's Center for Regional Analysis pointed out in its recent study for the 2030 Group of future Washington-area transportation, Connecting Transportation Investment and the Economy in Metropolitan Washington, October 2012. It forecasts a minute shift in the area's mode of transportation as reflected in the following observations (p. 5):
• Looking at similar measures from the transportation modeling, it shows
that the ability to change trends is very weak over time. From the base
year to 2040, 81% of the growth in all types of trips are auto, and the
overall change by purpose is close to zero. The share of change in trips
for all purposes, 2007 top 2040:
Mode Total Trips Change Share of Change
Drive Alone 4,302,900 52.3%
Auto Passenger 2,360,600 28.7%
Auto Total 6,663,500 81.0%
Transit 499,400 6.1%
Bike/Walk 1,062,300 12.9%
• For work trips only, there are only slight changes in share of travel by
mode, with a small drop in auto travel, a small increase in bike/walk, and
almost no change in transit:
Mode 2007 Share 2040 ShareAnd a slightly more detailed look at the Regional Activity Centers (RACs) in the highly suburban Dulles Corridor west of Tysons using information from the GMU CRA study suggests the suburban shift to use of public transit here by 2040 will also be relatively modest. In fact, the suburban communities west of Tysons use public transit substantially less now than the Metropolitan Washington area as a whole (14.8%-3.6% = 11.2% deficit) and will continue to do so in 2040 (15.1%-9.1% = 6.0% deficit). Indeed, the prospective Dulles Corridor share of public transit for the Dulles Corridor in 2040 is less that the area-wide transit share today by nearly six percentage points. This is forecast to occur despite completion of the $6 billion investment in the Silver Line and Fairfax County shifts in bus transit to help assure the line's success.
Auto Driver 67.8% 63.9%
Auto Total 76.1% 75.1%
Transit 14.8% 15.1%
Bike Walk 9.1% 9.7%
The experience portrayed here is much different than the experience along Arlington's Ballston-Rosslyn corridor over the last four decades. In general, that corridor sees current transit use at about 40% among its five stations and GMU CRA projects that, at the Clarendon/Court House RAC, rail use will grow to 44%.
A likely core reason for this sharp difference in transit--especially rail--use is that Arlington built Metrorail in a decaying close-in mixed-use environment. In contrast, the Dulles Corridor is a thriving, distant suburban market, especially Reston which has its own "downtown" in Reston Town Center as well as five village centers.
Both GMU's academic research and the real life experience of San Francisco's South Bay area are strong evidence that, in planning Reston's future, we must be wary of expectations of major shifts in the way people travel, especially commuters, even over a timeframe of 20-30 years. Given the traffic congestion in Reston now as the prospect of massive hikes in Dulles Toll Road rates, we should constrain growth and expand roadway construction--as well as encourage transit use through a variety of transportation demand management measures--to prevent gridlock on Reston's streets and the further erosion of Restonians' quality-of-life.