Prince George’s County has updated its transportation plan to include an extension of Metro’s Green Line to Fort Meade (which, one imagines, would be a step toward its eventually extension to BWI). Matt has some good comments on the plan:
[T]he key thing to keep in mind is that when youâ€™re talking about new heavy rail construction, the potential benefits can be quite large but you have to decide if you actually want to seize them…
If you added a Metro station there, would the local area permit the surrounding quarter mile or so developed as a fairly dense walkable community? Or would people hear about proposals to build on the green space and up-zone the built-up area and decide that would lead to too much traffic? Maybe instead theyâ€™ll want to just turn the undeveloped patch into another parking lot. Thatâ€™d be no good. And the existing land use patterns around Marylandâ€™s Green Line stations donâ€™t inspire a ton of confidence.
To expand on this a little bit, Metro is the region’s most expensive transit option, but it’s also the one with the greatest potential to drive development. Generally speaking, we want to plan our transit systems so that we’re maximizing the benefits we get for the cost of the investment. If Maryland isn’t prepared to zone for significant development around Metro stations, it would be very silly to make the large investment in Metro. Better to develop a commuter rail line or light rail line or both (depending on anticipated development and commuting patterns).
The Silver Line, to take another example, is an expensive investment. It would probably have been much smarter to simply connect Fairfax County destinations (and Dulles) with Arlington and the District via commuter rail but for the fact that the new Metro line is part of a major effort to increase density at Tysons corner. And meanwhile, I think the prospects for development along a circumferential line are significant enough to justify a Metro line, so I’m a little disappointed that the Purple Line will only be light rail (but grateful, of course, that it will be the high-investment light rail option).
For a long time, transit in the Washington area meant Metro, and any area that wanted to improve transit access immediately began pushing for a Metro extension. It’s nice to see alternatives developing, both because Metro investments are often too large to be considered for areas with less development potential, and because lower density areas’ focus on Metro has probably slowed transit investment (which might have moved forward more quickly if areas not suited for heavy rail had instead focused on more appropriate transit options).
One final point: Metro is a network. When a new extension is built, the additional connectivity increases the value of all the other nodes on the system. But while that increase in value is significant, it’s not nearly as great as the benefit conferred on people located along the extension, who suddenly have easy access to the whole of the system. And meanwhile, the usage generated by the extension does generate some direct and indirect costs on other users.
These costs are increasingly borne by users in the core of the system, where growth in the number of trains and passengers have led to crowded conditions on platforms and back-ups during peak periods. To some extent, this can be addressed by increasing peak fares, but given the obvious value of Metro, the growth in the system’s spokes, and the fact that the District is better suited than almost anywhere else in the metro area to handle increased density, it seems clear that new core capacity is needed (as well as a new river crossing over or under the Potomac).
Metro doesn’t stop running when it enters the District. If Virginia and Maryland want to continue to build Metro extensions, they ought to offer their full support to an effort to add capacity in the core.