Pending the results of a required Alternatives Analysis, over the next couple of years Sound Transit will select a technology and an alignment for High Capacity Transit from Northgate to Lynnwood. ST recently released its Early Scoping Information Report, and Adam wrote a nice piece discussing the relative merits of the 3 corridors under consideration (Aurora, I-5 and 15th Ave NE). The most likely alignment remains I-5, which is the cheapest, quickest, and shortest. Having lived in Denver for 2 years (2007-2008), I am well-acquainted with interstate light rail alignments, and I think there is much we can learn from Denver’s alignment choices.
More after the jump…
In 1999 Metro Denver voters approved a property tax increase to fund the $1.67B ‘T-REX’ program, which added 19 miles of light rail (E, F, G, and H Lines) and widened I-25 to as many as 14 lanes (Roads and Transit, anyone?). The project came in 3% under budget, opened nearly 2 years ahead of schedule, and has been heralded as a template for efficient government projects. Rail has dramatically increased transit’s mode share along I-25, and the system averages 60,000 riders per day. In short, Denver completed its T-REX corridors quickly, efficiently, and on the cheap by using an interstate alignment. (Voters were sufficiently pleased that in 2004 they authorized the $4.7B (now $6.5B) Fastracks program, a breathtaking 119-mile, 7-corridor rail expansion program. Predictably, the economic crises of the past few years have severely strained Fastracks’ budget, and the completion of several of its corridors is in doubt.)
What should we take from their experience? If we care at all about land use and non-SOV station access, almost nothing. Four years after service began, fully 50% of RTD riders access stations by car (see chart below), while a mere 25% walk and 1% bike . Despite ample land, there are few TOD opportunities south of the Colorado Blvd. Station, and too frequently passengers must access stations via lengthy pedestrian bridges and multi-story parking garages. In a story that must inspire the owners of Bellevue Square, access to the Park Meadows Mall originally required that a pedestrian cross I-25 twice, as the mall initially refused permission for RTD to provide access to County Line Station.
If we do build along I-5, I hope extensive planning priority will be given to TOD and non-motorized access. Again, here Denver is instructive. Take a look at the Louisiana/Pearl station, which is the only station in the T-REX corridor without any parking. Despite the retained-cut freeway, the street grid has been fairly well-retained and pedestrians have direct walk-up access to the station. Impressively, this station has a 95% walkshare.
By contrast, look at Southmoor Station. This station is cut off from the neighborhood to its west, and to access anything at all passengers must walk east under I-25, through a parking lot, and north to Hampden Avenue, over 1/2 mile in all. Not surprisingly, Southmoor has an 11% walkshare.
Lastly, look at County Line Station. Though Park Meadows Mall relented and allowed a pedestrian bridge to be built into its parking lot, the station is almost completely surrounded by surface parking, two freeways, and a couple of hotels. It’s 38% walkshare is likely due to transit-dependent mall employees making heavy use of the station despite the inconvenience.
There are good reasons to build along freeways (see Jarret Walker’s optimistic assessment), but usually the main reason is simply a nod to cost and political expedience. I think we can do an I-5 alignment well, but precedent is not on our side. Though Denver’s system has many strengths (speed, punctuality, peak frequency on combined segments), its reliance on freeway alignments permanently bisected its walksheds, severely limited TOD opportunities, and established a permanent pattern of driving to stations.
If our choice is truly “build along an interstate or not at all,” I don’t think any of us would ask that the North Corridor not be built. An I-5 alignment will draw impressive ridership, but its utility north of Northgate will be too dependent on the commuter market. After all, ST511 to Lynnwood (~2,500 boardings per day) isn’t crush-loaded outside of peak hours, but Metro’s 358 (~10,000 boardings per day) often is. Despite immense challenges, an Aurora alignment from Northgate to NE 205th St would add only 1-3 minutes to travel time, remove the need for parking garages at 145th and 185th, and present the greatest TOD potential and non-SOV station access. It would almost surely have to be elevated, and the Canada Line’s elevated footprint in Richmond makes me think that this would not be as distasteful as many suppose.