There has long been a regional consensus that I-405 Bus Rapid Transit would be a part of the ST3 program. But that general agreement has hidden a fuzziness about the form it would take. The December 4 workshop saw a range of options presented. The studies make a compelling case for a low-cost version of I-405 BRT, but complicate the case for doing much more. The eye-popping conclusion is that a range of investment levels between $340 million and $2.3 billion all produce the same ridership.
Staff presented “low capital” and “intensive capital” representative models. In between are a long list of a la carte options. There are two alternatives for a southern terminus; one at Angle Lake, the other at Burien TC. The “low capital” model leans heavily on existing infrastructure, and is less ambitious than any of the options examined in the previous set of studies in 2014.
Low Capital BRT
Staff analysis helpfully breaks out cost and performance by segment. Segment A, Lynnwood TC to Bellevue TC, is the most productive with up to 10,000 riders, about 60% of all the ridership on the BRT. 10 of the 19 miles are served via general purpose lanes on I-5 and I-405 (other than limited shoulder-running southbound on I-405). Only the portion between Brickyard and Bellevue can be served via HOT lanes. Segment B, Bellevue to Renton, runs entirely in HOT lanes, but achieves fewer than 1,500 riders. That would include a deferred project to build HOV direct access ramps at N 8th St in Renton.
Beyond Renton, there is little new investment. Segment C, Renton to Tukwila International Boulevard Link Station, would run in HOT lanes on I-405 and general purpose lanes on SR 518, achieving a respectable 3,500 riders with little cost other than vehicles. From TIBS, the service could continue to Angle Lake via BAT lanes on SR 99 (Segment D1), or to Burien Transit Center via general purpose lanes on SR 518 (Segment D2).
The total capital cost under $350 million is modest for the ridership, mostly because the highway infrastructure is largely existing or funded through WSDOT. 28% of the cost is for parking.
Intensive Capital BRT
The ‘intensive capital’ option adds several stations and upgrades others. It eliminates much of the interaction with general purpose lanes via added ramps in the north and BAT lanes in the south.
Continue reading “ST3: Bus Rapid Transit on I-405”
With the Spring 2019 service change, routes 21X, 55, 56, 57, 113, 120, 121, 122, 123, 125, and C Line began serving two stops on 1st Ave. This will be the first time this century that [ed: some of these] southwest Seattle routes will connect directly to Pioneer Square. Both stops are centered on King Street, albeit at the furthest end of the intersection, with the northbound stop closer to Jackson and the southbound stop nearly at Dearborn.
