Build the Purple Line, but make people wait longer for trains? Maryland officials might do that

Maryland’s new transportation secretary, Pete Rahn, is looking at ways to build the Purple Line more cheaply. While changing the route or swapping out light rail for buses aren’t on the table, Rahn says that less frequent service is one possibility.

Formerly the transportation secretary in Missouri and New Mexico, Rahn recently told the Washington Post he wants to take a “practical design” approach to the proposed light-rail line between Bethesda and New Carrollton. The $2.4 billion project already has federal and local funding, and Governor Larry Hogan has set aside some money in the state budget.

Hogan has asked Rahn to find ways to reduce costs. One way to do that, Rahn says, is to make the service less frequent. This might save money now, but it might make the Purple Line less effective while increasing costs in the future.

Under the current plan, the Purple Line would run every six minutes during rush hour and every 10 to 20 15 minutes during the rest of the time, from 5am to midnight on weekdays and from 7am to 3am midnight on weekends. That’s comparable to Metro service today.

Running trains less frequently means buying fewer trains and hiring fewer workers, which can save on operating costs. But it also makes the service less reliable if riders have wait longer for a train or to transfer, and that could hurt Purple Line ridership.

It also complicates the state’s public-private partnership with a company who would build and operate the Purple Line. If Maryland writes the contract for, say, 15-minute headways, then that company will design and build the line to that standard; changing the frequency would require an amendment.

Adding more frequent service later could also require buying more trains, which will be more expensive than just doing so now. And it might require the state to renegotiate its contract with the private partner, which would likely have the upper hand.

One solution could be to tie frequency to ridership benchmarks: as more people ride the Purple Line, the state could require the partner to provide more frequent service. That could help reduce costs in the beginning, while avoiding the potential for higher costs or contract renegotiation in the future.