Photo by Matt’ Johnson on Flickr.

Officials from the MARC and VRE commuter rail systems started discussing how to run trains from one state to the other through DC, instead of stopping all trains at Union Station, NBC reports. This is an important step on a long road (or track?) toward a better regional transit system.

In the segment, reporter Adam Tuss explains that while there are a lot of obstacles, there are also big benefits. “Those improvements could mean as much as two lanes of rush hour traffic on Interstate 95 or 66 could be shifted to the rails,” he says.

Commuters from Maryland could ride past Union Station to Crystal City, Alexandria, Fort Belvoir, or other job centers. Or they could transfer at L’Enfant Plaza to the Orange, Blue, Yellow, and Green lines to reach jobs in many parts of Virginia, DC, and Maryland. Meanwhile, Virginia commuters could ride to Rockville, Fort Meade, Baltimore, and more.

As Tuss also notes, a lot of obstacles remain. Matt Johnson outlined some of the hurdles in two posts. They include:

The railcars and platforms aren’t compatible. VRE uses low platforms and its cars can only access low platforms. MARC has a lot of high platforms and cars that can access both. Over time, VRE could buy compatible equipment, but until then, the only through-running possible is for MARC to send trains to Virginia, and maybe VRE could run on the Brunswick Line. Which is a good start.

The tracks don’t line up. The problem with VRE on the Brunswick Line (the one that goes to Frederick) is that the Brunswick Line tracks come into Union Station on the west end, while the tunnel to Virginia is on the east end. Trains can cross over, but they would block all of the other lines as they do, delaying other trains.

There aren’t enough tracks. There are 2 tracks on the Long Bridge across the Potomac, and 3 through L’Enfant Plaza. CSX controls the tracks, and lets VRE use some space on them, but only a limited amount. Except for one reverse-direction VRE train and a few Amtrak trains, all of the passenger trains go north in the morning on one track, and south in the evening. There are plans to add tracks (and platforms) at L’Enfant and a study going on for the Long Bridge, but more tracks are years and many dollars away.

There aren’t enough platforms. The L’Enfant and Crystal City stations have just one platform, on one side of the tracks. These stations would have to be rebuilt with platforms for both directions for MARC trains to usefully go to Virginia.

But all of these are engineering obstacles which just require some time and money to solve. If the project can substitute for widening I-95 or I-66 and one or more Potomac River bridges by two lanes, that’s a huge gain, and the equivalent highway project would be very expensive as well.

With through-running and more trains on MARC and VRE lines, the commuter rail lines could even act as a sort of express train alternative for Metro. Add in some of the new transit projects being proposed, the region’s heavy rail system could conceivably one day look something like this map I made five years ago:

While it might take years, it’s worth starting now. MARC and VRE (and DC, and Amtrak, and the federal government) should be talking regularly to develop a comprehensive plan for how to make this happen. Then the jurisdictions can start working to fund and design them piece by piece.

MARC and VRE are now stepping up. DC Councilmember Mary Cheh also put $500,000 from the District budget to help develop a regional commuter rail plan. This is a good time, because CSX wants permission to enlarge its Virginia Avenue tunnel through DC; that gives the public leverage to demand CSX also cooperate with projects to add commuter rail service.

It can be extremely hard to get multiple states to coordinate transit plans, but if officials in the various jurisdictions can agree on a way forward, we can all start pushing to make an intergrated commuter rail system a reality.

David Alpert is Founder and President of Greater Greater Washington and Executive Director of DC Sustainable Transportation (DCST). He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He lives with his wife and two children in Dupont Circle. Unless otherwise noted, opinions in his GGWash posts are his and not the official views of GGWash or DCST.