The proposed Purple (light-rail) Line in the Maryland suburbs of DC is an expensive transit project that does little to reduce congestion. To fix the problem, the state should move the route, switch to bus-rapid transit, and rebuild I-495.
Due to its density, the Washington D.C. area is one of the top places in the country for transit services. The existing WMATA rail network lacks an east-west connector in the Maryland suburbs of DC. Current rail lines funnel travelers into the heart of DC. Although the distance between Silver Spring and Bethesda is three miles, a trip on the red line takes 35 minutes. A direct transit route could take 10 minutes.
Unfortunately there are significant problems with the proposed line. While the line connects Bethesda, Silver Spring, and the University of Maryland most of the stops are in low-density residential neighborhoods. There are not enough riders in these areas. The next problem is that much of the route travels city streets without priority signaling; priority signaling gives the train an automatic green light when it approaches intersections. Without priority signaling the train will be no faster than current local bus services. Another problem is that the track will run next to an existing trail. This will increase noise and pollution for trail users.
But the most troubling problem is the lack of funding. The state plans to cover 50% of the cost. However, when the state gets a new governor in 2014, priorities could change. Maryland expects the federal government to pick up the other 50%. However, in another area project, the Dulles Rail Line, the federal government only covered 17% of the cost. Fairfax and Loudon counties were forced to pay for the remaining amount. The Dulles Rail Line is also funded by tolls on the Dulles Toll Road, a source of funding the purple line does not have. Maryland's gas tax is relatively high. With a significant percentage of funding for the purple line coming from gas taxes, raising that tax to increase funding for it, as some have suggested, is a bad idea.
There are several options to fix the problem. Maryland might fix the problem by moving the route north two miles into the much more congested Washington Beltway corridor. Using the beltway right of way but building a line north or south of the beltway would allow neighborhood connectivity but reduce the costs of acquiring land. However, quality rail requires its own track which is very pricey. While rail may be appropriate in the beltway corridor, we will not know until we see a detailed transportation study. The project should not proceed without an accurate assessment comparing the rail line to other transportation alternatives.
Another option is to keep the current route but use bus-rapid-transit (BRT). The BRT versus rail issue became an ideological fight between Governor O'Malley and former Governor Ehrlich. Now that the election is over, O'Malley needs to admit that for the proposed corridor, bus-rapid transit is the better choice. Since much of the corridor is surface-streets, a train offers no advantages--only a much higher cost. Once wires are installed for light rail, they cannot be moved. Customers would be stuck with the route.
Priority signaling and queue jumpers, which are bridges or tunnels, at the largest intersections will allow BRT to avoid congestion and travel more quickly than current local buses. If the area becomes much denser, a train can be added at a later date.
The best option to fix the problem moves the route, uses bus-rapid transit and rebuilds I-495 in Maryland. Virginia is adding high occupancy toll lanes in Fairfax County. Maryland has studied the concept but has no projects planned. Maryland could rebuild I-495 with a minimum of four general purpose lanes and two high occupancy toll lanes. Cost-effective transit stations could be placed along one side of the road or in the median to allow buses to pick-up or drop-off customers. The HOT lanes will allow free use to multi-person carpools and free flow of vehicles. This would encourage carpooling and vanpooling for east-west trips in the northern suburbs. Single occupancy vehicles may choose to use the lane by paying for it. This would help to pay for the cost of the project.