If streets are gridlocked, how can mass transit work? Human Transit, a.k.a. Jarrett Walker, explains:
A few years ago I had a memorable ride on the Ventura Blvd Metro Rapid from Warner Center to Sherman Oaks. The service flowed smoothly through Tarzana and Encino but then got stuck in two miles of gridlock leading up to I-405, as it often does, and the crowded bus spent 20 minutes going almost nowhere. It made no sense. Cars can only fit onto 405 at a certain rate, especially if they’re going over Sepulveda Pass. So in the current arrangement, the surplus traffic is stored blocking Ventura Blvd. Why do you give over the entire width of Ventura Blvd, and effectively shut down the street, just for the purpose of storing waiting cars? Why don’t you set aside a through lane for transit (and perhaps also for taxis, HOVs, and certainly for emergency vehicles) so that efficient use of the street can continue even as the cars pile up? What would be the effect on traffic? Simple: the pile of stored cars would be narrower and longer. But meanwhile, people could get where they were going, and emergency vehicles could get through to save lives and property.
Chokepoints in a network are huge opportunities for transit, but only if transit can get past them. This bit of Ventura Blvd is one example. Another is the Sepulveda Pass itself. Caltrans is widening the freeway to add HOV lanes, which will finally give buses a clear path around gridlock, so that from the Valley to Westwood they can start offering the only truly reliable means of getting through the Pass. If it works reliably you may see a range of services extended through the Pass to broaden the reach of that advantage.
But Los Angeles is almost done widening roadways. It’s time to make hard choices about how to apportion the space that you have. The great boulevards of Los Angeles can be, in their own way, as magnificent as the boulevards of Paris. In the last decade Paris has added bus lanes on virtually every one of its boulevards, mostly at the expense of traffic lanes. Traffic isn’t any worse than it was, because once people see that transit is getting through reliably, some of them choose to use it.