ST3: Kirkland-Issaquah Light Rail

Not so long ago, prospects for an ST3 investment in rail from Totem Lake to Issaquah seemed remote. There were too many competing priorities within a 15-year ST3 program, making a deferral to ST4 likely, and motivating examination of BRT between Bellevue and Kirkland. In an extended program, it's suddenly feasible, but the proposed alignment has weak connections to the most important destinations.

The project is a 17.5 mile rail line from Totem Lake to Central Issaquah connecting nine stations. From the north, the line generally follows the Eastside Rail Corridor, briefly interlining with East Link near Wilburton station. This is also a transfer point to East Link trains serving downtown Bellevue or Seattle. Near the historic Wilburton trestle, the line transitions to the east side of I-405 and then to I-90 in Factoria. Beyond Factoria, the line generally follows the I-90 median to a terminus in Central Issaquah.

There are eight new stations, four each on Segment A (Totem Lake - Wilburton) and Segment B (Wilburton - Issaquah).

Segment A serves four stops in the Kirkland area. An added stop at NE 112th St means this is one more than the previous studies, improving access within the southern part of the Totem Lake neighborhood. Other Kirkland stops are at NE 128th St (adjacent to the freeway BRT station), at NE 6th St (southeast of downtown), and at the South Kirkland P&R.

Segment B also serves four stations (after Wilburton); in Factoria, at Eastgate, at Lakemont Blvd, and in Central Issaquah. The Factoria and Lakemont stops are new to this study. The Factoria station, near Richards Rd on the north side of I-90, will improve access along the Eastgate/I-90 corridor which seems too sprawling to be well served via Eastgate alone. While the location isn't ideal for Factoria riders, it's perhaps as close to Factoria as the line can get while avoiding the environmental and engineering challenges of Mercer Slough and the I-405 interchange. The added stop at Lakemont would be a park-and-ride facility.

Kirkland may not be impressed by a Kirkland-Bellevue rail segment lacking walkable access to the downtown of either city. Issaquah, on the other hand, intends to concentrate future growth within the Central Issaquah area adjacent to the planned station. Travel from Issaquah to Seattle via Wilburton may appear circuitous, but no more so than express buses terminating into Bellevue Transit Center.

One potential outcome is a split-mode service on the corridor. An Issaquah rail line could terminate at Wilburton, with a transfer to Kirkland BRT, and a turn-back for the trains at the East Link OMSF. (Alternatively, a Kirkland-Bellevue rail line could include tail tracks in the ERC if built without the leg to Issaquah).

Travel times are healthy, just 16 minutes from Wilburton to either Issaquah or Totem Lake, with peak headways of 7.5 minutes. Estimated capital costs are up to $3.4 billion (surprisingly high for an alignment that mostly comprises highways and railroad ROW). Ridership is estimated at 12-15 thousand.

One way to observe the access challenges is to compare the population and employment density around stations served by this and other Eastside projects. Even with projected growth in the regional centers served, density around stations is much lower than even I-405 BRT. Nobody thinks of I-405 BRT as serving urban places, but the projected density around I-405 BRT stations in 2040 is 10-13 population/acre and 18-22 jobs/acre. This line is scored at just 8 population/acre and 13 jobs/acre.

The Kirkland BRT would outperform in serving comparatively dense places. Whereas the rail stations average 21 activity units in 2040 (a PSRC-favored measure that sums employment and population per acre), the Kirkland BRT stations average 46. In aggregate, Kirkland's BRT would serve 48% more residents and 134% more employees on a much shorter line. The ability to place stations in downtown Kirkland and Bellevue really matters.

Are the station access challenges fixable? There is no appetite for another line through downtown Bellevue, or revisiting the Mercer Slough. Interlining with East Link creates operational issues (and indeed project construction on Totem Lake-Issaquah will interrupt East Link operations at the short interlined section on the ERC). This is a case where the easy alignment misses the key destinations, and the density of the Eastside may not be enough to support a better pricier rail line.