[wburg]

What I had in mind for an airport bus line was maybe a bit different--a high-frequency express bus line that basically runs back and forth between the train station and the airport, every 15-20 minutes, using I-5, ideally with a HOV-striped middle lane for the bus. Actual BRT is something different--it's more like light rail, with its own dedicated travel lane, stations instead of minimal bus stops, and vehicles with multiple entry/exit doors. If what you were talking about was a dedicated BRT route running north through Natomas on its own right-of-way to the airport through the suburbs-to-be north of North Natomas, then yes, I probably scoffed at that, because BRT infrastructure isn't much cheaper than light rail infrastructure. Especially if you include features like a bridge crossing over the American River and a trestle running through the stretch between North Natomas and the airport that still floods. When operating costs are taken into account, BRT is more expensive per passenger. The problem with any dedicated transit line through that particular bit of floodplain is that it provides additional excuses for more greenfield development. And it is continued greenfield development that has drawn energy away from infill in our existing urban footprint.

Light rail does spur development, but not the sort of high-density development you're thinking of. Like its predecessors, interurban electric railroads and steam commuter railroads, it encourages suburban villages based around the train lines. Before the advent of the automobile, they tended to cluster around the station, and in the post-automobile era, "park-and-ride" lots became common. This messed up a lot of older commuter-rail towns, as their downtowns were often scarred to make room for a couple blocks of park-and-ride.

Streetcars are a bit different--they encourage a medium range of density. Midtown, Oak Park and East Sacramento are products of the streetcar--a mixture of single-family homes, small multi-family buildings and commercial strips, with the highest-intensity uses where the lines all converged downtown.

Generally, if a neighborhood is already built out, adding a streetcar or LRV line doesn't drive much development--but infill in those neighborhoods can take advantage of rail transit's presence, since it needs less auto infrastructure. If the transit isn't built first, you end up with places like North Natomas and Laguna West--entirely car-dependent, heavily zoned and physically segregated neighborhoods that lack walkability.

That being said, while there isn't a ton of infill around light rail stations, it certainly exists, at least in the central city, and more is underway. While some may assume that Light Rail has cooties because suburban commuters ride it, I disagree with that assessment and ride it very frequently. I'd rather have them riding Light Rail than driving--it reduces peak-hour commuter loads by tens of thousands of cars every day, and reduces parking demand by an equal amount. If not for Light Rail, even more blocks of downtown would be filled with urbanity-deadening parking lots and parking structures.