The opportunities and dangers of incomplete bus rapid transit
from the Human Transit blog:
the opportunities and dangers of incomplete bus rapid transit
One of Bus Rapid Transit's great virtues is that unlike rail, you don't have to build a complete, continuous piece of infrastructure if you really only need segments of one.
Here in Portland, for example, the Barbur corridor -- now being studied for BRT or rail -- features a series of congested chokepoints with generally free-running traffic in between them. Here, a BRT facility that got transit through the chokepoints reliably probably wouldn't need an exclusive lane in the free-flowing segments, because traffic in those segments would continue to be metered by the chokepoints and thus remain uncongested. (Congested chokepoints meter traffic just as ramp meters do: they limit the rate at which cars can enter a road segment and thus reduce its chance of becoming congested.)
Unfortunately, Bus Rapid Transit can also be implemented in exactly the opposite way. Severely congested chokepoints are generally expensive places to design transit priority for, especially if you're unwilling to simply take a lane for transit. So we often see BRT projects that are missing where they are most needed. The Boston Silver Line 4-5, like the Los Angeles Silver Line, can get stuck in traffic downtown. New York's supposed BRT is so compromised that many refused to call it BRT anymore. Even the world-class Auckland North Shore Busway disappears as it approaches the Harbour Bridge. ................(more)