No Silver Lining for the Silver Line?

metro_map

Blue dot indicates chokepoint where the Silver, Orange and Blue lines compete for restricted capacity on the Potomac River metrorail tunnel.

by James A. Bacon

By all accounts the Silver Line extension serving Tysons, Virginia’s largest commercial district, has enjoyed a successful start. Ridership is strong and in line with expectations. But a new issue arises. How much of the Silver Line’s traffic is cannibalized from the Orange and Blue lines?

The problem is that the three Metro lines must squeeze through the same Potomac River bridge to enter Washington, D.C. That bridge has a finite capacity of 26 trains per hour.  Trains assigned to the Silver Line are trains that cannot run on the orange and blue lines.

Is this a problem? Del. James M. LeMunyon, R-Oak Hill, worries that redistributing Metro riders between different lines will do little to alleviate regional traffic congestion. He broached the issue two days ago in a letter to Richard Saarles, CEO of the Washington Metropolitan Area Transit Authority (WMATA).

The primary problem created by the Silver Line is the fact that it operates by reducing peak period service on the Orange Line by 42 percent, from 19 to 11 trains per hour. Likewise, Blue Line peak service has been reduced from seven to five trains per hour. These ten former Orange and Blue Line trains now comprise the Silver Line during peak periods, for a net increase of zero Metrorail peak period trains on those lines. … The Silver Line does not represent increased train service, but only cannibalizes previous Metrorail service.

LeMunyon worries what will happen to the thousands of commuters who drive or take the bus from points west to Vienna, where they board the Orange Line. For many commuters, he maintains, switching to stations on the Silver Line will not be a viable option. It’s conceivable that Metro rail, after the expenditure of roughly $3 billion to build the Silver Line, actually could lose passengers. Former Orange Line commuters could switch to Interstate 66, making that freeway even more congested than it already is. “For these people,” he writes, “the Silver Line has no silver lining.”

In concluding the letter, LeMunyon said he hoped that WMATA would adjust the frequency of trains on each line to match customer demand, and if it made sense to move Silver Line trains back to the Orange Line that WMATA would do so.

Bacon’s bottom line: It is inconceivable to me that transportation planners did not take all of these factors into account when calculating the benefits of the Silver Line. If Orange or Blue Line trains are under-utilized at present, shifting some to a Silver Line running at full capacity actually could increase ridership. But, hey, you never know. It will be interesting to watch traffic counts at Silver, Orange and Blue line Metro stations and along Interstate 66 to see how commuters adapt.

I have to say, if it turns out that the expenditure of nearly $3 billion does not result in significant additional Metro ridership — one of the project’s big selling points — don’t be surprised to see lynch mobs forming.