Mapping ST3 Parking

Angle Lake Parking (Sounder Bruce - Flickr)

Though the light rail projects in Sound Transit 3 (ST3) took up most of the oxygen during the run-up to the Board vote to put the measure on the ballot, there was less public discussion about station access. Advocacy groups won $100m for a Station Access Fund (consisting of things like sidewalks, signalization, bicycle lanes and parking, and transit restructures), but lost their broader goal of parity between access funds for cars and all other modes. Parking still took the lion's share of access funds, with $600-700m for vehicle parking.

So I thought I'd put together a map to visualize the extent of onsite, publicly provided parking at Link stations following a full ST3 buildout. Private paid parking (such as at Mount Baker) is not included, nor is nearby public parking that will likely see light rail use (such as Green Lake P&R for Roosevelt Station). ST3 would boost Link station-area parking by about 45%, adding roughly 8,300 new stalls (at $80,000 per space) to roughly 18,000 existing spaces from ST2, Sound Move, and other prior agency projects such as Northgate.

The resulting map comes with many caveats, first and foremost that final parking tallies are dependent on later project development and design considerations, and are thus subject to change. The map includes parking built prior to ST3 as well, such as at Tacoma Dome or Everett Station, so the map is intended to be a cumulative total rather than just ST3-funded projects. I've attempted to subtract net new stalls from existing totals, such as when a surface lot becomes a structured garage, but it's likely I made some mistakes along the way.

The system we'd get would be similar to DC Metro in many respects, fully tunneled and zero parking in the urban core, fully traffic-separated, and with both poor land use and gobs of parking on the exurban periphery. Like DC Metro, there would be the occasional urban-ish station, such as Downtown Redmond. Unlike DC, we'd have historic cities (Everett/Tacoma) anchoring the ends of the lines. The scope of our Everett-Tacoma spine would be unprecedented, equal to straightening out DC's Red Line and then doubling its length.

The dual nature of our system is clear from its parking provision, with a genuinely urban subway that becomes interurban, parking-fed commuter rail on the periphery. From a current or transitional land use perspective, this makes some sense. But it bodes poorly for the suburban TOD that is the main hope for filling the suburban trains off-peak.

Lastly, this further shows how parking fundamentally can't scale. The 26,000 total parking stalls are less than just the ridership growth from ULink's two stations. If every stall were taken and assuming 1.5 people per car, the resulting 40,000 people would be less than 10% of projected ridership. Those 40,000 riders would only fill 50 crushloaded 4-car trains, which at 6-minute headways on 3 lines would mean roughly 1.5 hours worth of capacity every morning per line, with lots still full as early as 7:30am.