In the Houston Chronicle this past weekend, David Crossley and I made an argument for urban rail. We said that rail transit that serves dense employment centers, neighborhoods, and non-work destinations is more useful and more cost-effective than rail designed only for suburban home-to-downtown work trips. Further more, we argued, urban rail serves suburban commuters as well.

Want some more evidence? Rail transit projects don’t come with control groups — we can’t clone a section of a city, build two different rail lines, and compare the results. In this case, though, there’s an interesting comparison to be made between two remarkably similar rail systems.

San Francisco is in the 5th largest metropolitan area in the country. Washington DC is in the 4th largest. Both cities have old, urban cores with major employment centers surrounded by extensive post-war suburban development. In the 1960s, both decided to build a heavy rail system. And not only do those two systems use very similar technology, they are nearly the same length (104 miles vs. 106 miles).

There is one significant difference between San Francisco’s BART and Washington’s Metrorail, though: Washington has 2 1/2 times the ridership (902,100 average weekday boardings compared to 338,100.) Why? I’ve lived in both places, and I’ve ridden both systems. And I think the difference is that BART is primarily a suburban system while Metrorail, even though it serves the suburbs as well, is at its heart a urban system.

What do I mean? Let’s compare.

• BART serves the suburbs. Metrorail serves the suburbs and the urban core.
  BART’s furthest station is 25 miles from downtown SF as the crow flies, across two small mountain ranges. Metrorail’s furthest station is 15 miles from the center of DC.
  BART has a single line through the city of San Francisco. It serves Downtown and one urban neighborhood, the Mission. BART does not serve San Franciso’s densest neighborhoods on the north side of the city, which have no high-capacity transit (the Geary Street bus carries 50,000 trips a day, but there’s no rail in that corridor), nor does it serve major destinations like the UCSF medical center or San Francisco State University. Metrorail has 5 lines through Washington, serving many neighborhoods in all parts of DC. Metrorail also serves many more suburban employment centers than BART does.Most of Metrorail’s riders are from outside DC. But even suburban park-and-ride riders benefit from Metrorail’s urban connectivity. If you work in DC but outside downtown you can still take the train; the same goes if you work in a suburban employment center like Crystal City or Silver Spring. And if you work at any of those places Metrorial offers you mobility during the day, to go to meetings, get lunch, go to a doctors’ appoinment, take evening classes, or go to dinner with friends before heading home.On the maps below, yellow is the urban core (San Francisco and DC). Red is the downtown employment core. Orange dots are stations serving other employment centers. (Both maps are to the same scale; click on each to see a larger version).BART is left; Metrorail is right.

• BART saves money by using existing rights of way; Metrorail maximizes ridership by puting lines where the transit demand is. The yellow highlighting represents BART lines built along existing railroad tracks or freeways; the purple lines are tunnels under natural obstacles. That leaves only the San Francisco subway, a two-station subway in Downtown Oakland and a three-station subway in Berkeley. The latter — which serves the University of California along with Downtown Berkeley — was built only because the city contributed money; BART planners wanted to put the station a mile from the edge of the UC campus. Metrorail uses some existing rail lines and a Virginia freeway corridor, but the majority of the system is in subway alignments that serve neighborhoods and employment centers. Its planners repeatedly spurned existing rights of way for parallel alignments often less than a mile away that go where the people are.

• BART stations are where the cars are; Metrorail stations are where the people are. The vast majority of BART stations are car-oriented. The “typical” BART station is an elevated structure surrounded by park-and-ride lots in a low-density neighborhood. Over half of Metrorail stations, by contrast, don’t even offer parking. These stations serve employment centers (urban and suburban), universities, neighborhood crossroads, and residential areas. On the map below, the area of each station dot represents ridership at that station. Blue dots are stations with parking lots; red dots are stations without parking. Note the high ridership at Metrorail’s parking-less stations. And note that even though BART stations are much further apart than Metrorail stations, they typically have less ridership. The bottom line: 54% of the people boarding BART in the morning came by car compared to less than 45% of the people boarding Metrorail. Over the course of the day, over 60% of trips on Metrorail start with the passenger walking to the station.

BART and Metrorail may look alike. But they are fundamentally different systems. BART was conceived as an alternative to suburban commutes. Metrorail was conceived as an urban rail system. BART, in other words, tries to serve 2 trips a weekday, and Metrorail tries to serve every trip, every day. It’s no accident that it carries 2 1/2 times as many trips.

Metrorail has another less quantifiable achievement to its credit. Everyone I know who visits Washington ends up marveling about the subway system. Why? Because they found it useful. So do the people who live there, and they find it hard to imagine the city without it. Washington, a city with no rail transit and a declining bus system 30 years ago, now has a transit culture. I spent a summer in DC, living in an apartment near the Friendship Heights station and working at the National Building Museum, just above the Judiciary Square station. Everything I wanted to do — go to work, go home, shop, see a play, go to the museums, go to the park — I could do by Metrorail. Transit planners made the right choices 30 years ago, and my daily life was better for it.