Purple Line Planning

Manage Better: Improvements would include limited-stop bus service, more green-light time for buses and better bus stops. Metrobus routes would be modified to improve reliability. By 2030, traveling the 16-mile corridor would take 108 minutes at an average round-trip speed of 9 mph. There are practical limits on giving more green-light time in this east-west corridor. The big commuter roads that cut across that route, including Connecticut Avenue and Riggs Road, would suffer even worse congestion if they had to endure more red-light time.

Buses and Trains : Maryland looked at six basic options for bus and rail, ranging from simpler, lower-cost systems that mostly share local streets to more sophisticated and expensive versions that move faster because they have separate lanes and some tunnel segments. The top option for light rail would cost $1.6 billion today. That high-end system would offer the fastest travel times -- 50 minutes end to end at an average speed of 19 mph -- because of its higher investment in tunnel segments. The bus options would have slower travel times than their light rail counterparts and also have lower operating costs.

Cost-Effectiveness: In evaluating local projects for financial support, the Federal Transit Administration cares about cost-effectiveness. Based on that measure, the bus alternatives would be slightly more cost-effective than the light rail alternatives, with the medium-investment bus system being the most cost-effective. The medium-investment light rail is the most cost-effective of the rail alternatives. By current FTA standards, all the alternatives fall into the "medium" range of acceptability except for the low-investment light rail, which would rate as "medium-low."

Next Steps

· The documents are available for review and comment until Jan. 14. Then the Maryland Department of Transportation and its Transit Administration will adopt one of the options. Maryland Transportation Secretary John D. Porcari said in an interview that the choice should not be limited by current economic conditions. The state needs to think ahead and think big about its transportation system, he said.

· In spring 2009, the MTA expects to submit a proposal to the FTA and hopes for a favorable rating that would lead to partial federal funding.

· To build a bus or rail system after receiving a favorable rating, the state must then prepare a Preliminary Engineering and a Final Environmental Impact Statement.

· Maryland would then seek to move from the planning and environmental review stage into design and construction. (The process is similar to what Virginia is going through to build the new Metrorail link through Tysons and out to Dulles.)

· The very earliest construction on the Purple Line could begin is 2012. It probably would take three to five years.

-- Robert Thomson