Photo by dionhinchcliffe.

Washington Post Metro editor Robert McCartney is the paper’s newest Metro columnist, replacing Marc Fisher. In his inaugural column, McCartney recommends (among other things) a circumferential Metro line around the region.

In a live chat, McCartney expands upon the reasons to make big investments in transit:

1) We’ve got to link up the spokes of the existing Metrorail line, to make commuting by transit more attractive and get cars off the road. It’s absurd that taking the Red Line from Silver Spring to Rockville requires going downtown.

2) With gasoline prices headed higher, we’ve got to reduce dependence on cars.

3) With the climate endangered by greenhouse gases, we’ve got to reduce dependence on cars.

4) With traffic so clogged that the region risks getting in a position where people don’t want to come work in the region because of the congestion, we have to reduce dependence on cars.

This morning, Cavan also argued for more redundancy in our transit network. However, many transit activists feel that given the lower land densities of the suburbs, light rail is a more cost-effective mode than heavy rail Metro. Metro everywhere would be great, but given limited resources (and already wide roads), is it better to build cheaper lines in more places? McCartney talks about getting from Silver Spring to Rockville; a circumferential Metro line would, at best, get you to a station closer in on the Red Line, requiring a transfer to Rockville. Meanwhile, light rail or even BRT on Viers Mill Road could connect people directly. Or, better yet in that case, let’s make better use of the track connection we already have.

McCartney wants his Metro line “parallel to the Beltway,” but isn’t clear if he means right along the Beltway, as in this proposal from 1990. He does suggest using the American Legion Bridge, and as an example of the utility of the Metro ring, he suggests people can travel from Montgomery Mall to the Tysons Galleria. Nobody will park at one huge mall to take a train to the other. A heavy rail Metro line, especially, would be most useful connecting the densest areas, and except for Tysons, that’s not along the Beltway.

Heavy rail is best in denser, more urban areas. If McLean and Potomac were interested in turning cul-de-sac developments into walkable neighborhoods like Cleveland Park and Brookland, maybe one day Tysons would be a twin city as Zachary Schrag suggested on his chat. But that’s not going to happen. Earlier in his column, McCartney chastises Maryland and DC for not jumping on the bandwagon to add new car lanes across the Potomac to link to those Virginia is building. This is a common reaction, like the impulse to add Metro everywhere. But we don’t have unlimited money to both reduce car dependence and increase car capacity.

Lots of Metro is appealing. I’ve made maps of prolific Metro expansion. In many ways, they’re more exciting than streetcar and light rail plans, generating more comments and potentially more activism. Maybe a Washington Post columnist ought to stir Marylanders’ blood with the biggest visions, to get their elected officials to support very expensive transportation bills instead of car tax credits. But then when we get down to making actual plans, more lines beat big lines, and core capacity is more important than peripheral extensions.

We’ll look forward to more advocacy for transit and reducing car dependence from McCartney. We agree on the fundamental goal. Whether Metro, commuter rail, light rail, BRT, HOT lanes or no lanes, will best reduce car dependence is one of the most fascinating debates in metropolitan areas around the globe.