In the comments to my last post on transfers, a few people referenced Jarrett Walker’s excellent post on Seattle’s prospects for carbon neutrality, which discusses Seattle’s geographic “chokepoints” such as lakes and cliffs. Some commenters argued that these chokepoints make a gridded bus network impossible, but I don’t think that’s right. Walker’s point is simply that geographically-induced chokepoints can improve transit usage, provided enough of the capacity in the chokepoint is given over to transit*:
Transit planning is frustrating in such a place, but road planning is even more so. Ultimately, Seattle’s chokepoints have the effect of reducing much of the complex problem of mode share to a critical decision about a strategic spot. If you give transit an advantage through a chokepoint, you’ve given it a big advantage over a large area.
None of this is inconsistent with having a grid. If transit is given priority at critical chokepoints (crossing Lake Washington or the Ship Canal, say) then transit suddenly has a major advantage throughout the city. This advantage increases the more grid-like the system is, since you can increase the area of the city that’s a single transfer away from using transit across the chokepoint.
As I said in the last post, Metro does a fantastic job of providing one-seat rides to downtown during rush hour, but it can (and should) push to provide better all-day access in places where land use patterns warrant it. Given the looming budget crisis and limited resources, exchanging one-seat rides for all-day mobility via transfers should definitely be on the table.
*Another great Walker post, on the Portland grid’s 30th anniversary, discusses the political challenges of moving from a radial network to a grid.