In 1995 and 2007, voters struck down measures to build and expand regional rail at the ballot, only to pass both the following years (1996 and 2008, respectively). In both instances, the approved measures were scaled down in scope from their predecessors, which has since unleashed quite a bit of consternation over the what-ifs and the woulda-coulda-shouldas had we built rail out to places like Tacoma, Everett, and Issaquah.
The question of how far we should extend rail is a practical and worthy conversation to have. Rail, by its mathematical nature, performs best where there are the highest concentration of riders in the least amount of space. And as a result, productivity will only decrease as trains travel across longer distances and lower population densities. When you get to these kind of routing typologies, freeway segments and park-and-rides are usually thrown into the mix to net a broader drivershed-based catchment area.
The innate danger in operating these low-productivity segments is that train capacity and hours, that could have gone to serving dense urban core populations, essentially go to waste. If you take a look at some of the newer expansive light rail systems built out west, you’ll notice that while ridership isn’t exactly in the tank, productivity measures fare terribly when compared to urban systems.
|Annual boardings||Boardings per hour*||Boardings per mile*|
*Annual unlinked passenger trips over revenue vehicle hours/miles, data from National Transit Database 2010
Denver and Dallas, for example, trail the pack when matched with powerhouses like San Francisco and Boston. While it’s not the fairest comparison to make, it’s a cut-and-dry indication that such sprawling systems will almost certainly have a long-term ridership plateau with low-density land use patterns and park-and-rides limiting growth. With lower densities served and longer distances traveled, ridership for every unit of service operated is held to a minimal level.
Whether the same lessons are applicable to our region is debatable. The three oft-cited ultimate termini of our regional rail network–Everett, Tacoma, and Issaquah– are far removed from the urban core of Seattle, separated by sprawling low-density areas that house a limited number of rail riders and would almost certainly warrant large expensive parking garages to lure ridership. Low-performing segments could also be used by transit opponents as a political tool to justify modal bias against rail.
Land use considerations also carry their own implications. Building our rail network to chase sprawl runs the risk of encouraging people to live farther away from the city center, shifting demand for housing that would be most valuable and effective within Seattle. And as many of these low-productivity suburban and exuburban segments would be sited along freeways with park-and-rides to boot, limitations of development potential would stifle the system’s long-term utility.
Nonetheless, given the region’s political framework, the practical considerations of withholding rail expansion to cities like Issaquah and Tacoma may be moot, as they would effectively cause Sound Transit to renege on its regional obligations. Above and beyond, it’s important to remember that Seattle remains the powerhouse for transit ridership and economic development, renderings efforts like Seattle Subway and joint rail planning to Ballard the top of anyone’s priority list.
Disclaimer: The author is currently employed as a temporary worker for Sound Transit. Any opinions in this article are his own and, in no way, express the views and policies of his employer, past or present.