Every now and then there’s second guessing of the decision to route Central Link through the Rainier Valley instead of a more direct route to the airport down East Marginal Way. The idea is that a faster trip to Seatac would boost ridership, and more importantly, make South Link a better competitor with existing freeway express buses.
I have three basic objections to this line of argument:
- Ridership and Federal Funding. Station boarding data shows that about half of Link trips begin or end in the Rainier Valley. It’s true that some people would board in Georgetown or along Boeing Field, but it’s obviously a much smaller market and anecdotal Route 124 performance* doesn’t suggest robust demand. Cut ridership by a little less than half, and it threatens federal funding and offends basic cost/benefit considerations. Furthermore, bus transfer opportunities from South County are almost by definition riders brought from buses, which FTA formulas frown upon. And of course, North subarea savings couldn’t have been used to extend the line further south.
- Low Development Potential. The idea of an MLK alignment is that there is a lot of development potential to join existing reasonably dense neighborhoods on either side.** The East Marginal Way walkshed is fundamentally limited by an airfield on one side and a river on the other. Furthermore, Seattle has shown no interest in rezoning these areas from industrial, and the economics of redevelopment are fundamentally limited by environmental contamination issues. The big employer, Boeing, has tons of free parking on their campus there.
- It’s not a Commuter Line. Ignoring the Rainier Valley to increase speed on South Link is a direct sacrifice of all-day ridership to provide better connection between distant homes and jobs. Although it makes sense to serve work trips wherever possible, optimizing it for commutes gives you commuter rail. Light rail and subways are about providing high-capacity all-day connectivity. Sometimes you have the money to do both through grade separation, as is the case with North Link. That wasn’t the case here. I would rather run express buses to Federal Way forever than skip good, close-in markets for rail.
Next: the outlook for constructing a bypass in the future.
* How about some spring 2010 performance data, Metro?