Perversely, the writer will find it easier to commute to Washington from Baltimore than he would find it to commute from, say, Towson (a dense inner-ring suburb on Baltimore's north) to Arbutus (a dense inner-ring suburbs on Baltimore's southwest). This is because Baltimore, like many US cities not named New York, Chicago, or Washington, has an appalling joke of a mass transit network. (Actually, D.C.'s isn't that great -- big chunks of the city have no subway service -- but it's better than most other places). He can commute to DC because of the MARC rail line, and then use the DC Metro to get around Washington. If his commute was in the opposite direction, however, he would take the MARC line to Baltimore, and then... call a cab, because unless he happened to be going to a destination along the single (slow, unreliable, nearly useless) Light Rail line in Baltimore, the train stations don't tie into any decent, usable mass transit network in Baltimore.

I am a big believer in mass transit (as well as the ne plus ultra of green living, LIVE CLOSE TO WHERE YOU WORK, a rule which the author violates), but the truth is that in many parts of this country, cutting down on commuting miles by using mass transit is very difficult to do. For a variety of reasons, ranging from geography to short-sightedness to racism, this country chose to invest most of its postwar transportation dollars in an ever-expanding web of roads, rather than decent mass transit.

Every city should have an extensive subway and/or elevated train network that connects different parts of the city and its immediate suburbs, and all cities should be connected to neighboring cities by regular, affordable rail service, and they should run 24/7, not just during peak commute hours. (If a resident of Georgetown wishes to go bar-hopping in Baltimore's Fells Point, she had been finish her nightlife by 10 p.m., because there's no rail service between the two cities after that.... and Fells Point doesn't start to get interesting until 10 p.m.)

No conservation plan being proposed in the US would create as many jobs or eliminate as much carbon consumption as the construction of good, comprehensive mass transit networks in every major American city.