The 520 workgroup released their final recommendations on Friday. Of special interest to those interested with bus operations on the Seattle side are the white papers discussing transit priority and the second bascule bridge.
The not-obvious-yet-crucial consideration is construction of the second bascule bridge, which expands Montlake Blvd. from four to six lanes. The second bridge has always been in the plan, but there was substantial neighborhood opposition to destroying two homes and increasing overall vehicle volumes.
Unless and until that bridge is built, transit/HOV lanes on Montlake Blvd will extend northbound from the 520 offramp to Hamlin St, and the existing southbound lane just below Pacific, but not on the bridge itself. The workgroup looked at going to only 1 general purpose lane on the bridge in each direction, but
After reviewing a VISSIM model showing the existing bridge with an HOV lane in each direction and exploring the challenges related to channelizing HOV lanes in the corridor with such a configuration, the subgroup determined that this option would have significant negative impacts on traffic and transit operations along Montlake Boulevard and SR 520.
There also will be a southbound HOV left turn lane onto the onramp.
WSDOT will install signal priority equipment at four intersections on Montlake Blvd. WSDOT’s analysis indicates that operations improvements will reduce congestion enough that this priority operating them should be unnecessary except during special events. However, the use of these will ultimately be up to SDOT.
There will be performance measures that trigger construction of the second bridge that are related to the performance of all modes of transportation. If these triggers activate and WSDOT overcomes forthcoming political opposition, only then will the bridge be built. More after the jump.
If and when a second bridge is built, WSDOT will construct HOV/transit lanes, on the inside northbound and on the outside southbound. As described previously, these are meant to enhance performance of all buses turning left on Pacific or continuing south on 24th Ave, not to enable a stop anywhere near the light rail station. This is a subject for a whole different post, but the envisioned stop locations predict a walking time to the station anywhere from 3:25 to 5:13, largely because Metro sited the stop to minimize walking times for the larger group of people headed to the Medical Center or University.
WSDOT did consider an outside northbound lane with a dedicated left turn signal across traffic onto Pacific St. This light would have allowed only one bus to turn per cycle, so bunched buses would have waited 180 seconds for each bus ahead of it in the queue. It would also have increased general congestion on Montlake.
No queue jumps. Lastly, queue jumps for buses were not recommended in order “to respect the historical nature of the community.”
One of the big concerns is that the removal of the Montlake Flyer Stop be mitigated with a quality transfer to University Link. At the peak, buses are scheduled to take 16 minutes to get from the Flyer Stop to Westlake. U-Link should take 8, but assume about three minutes are spent descending to the platform and waiting for the train. With a three-minute walk from the northbound stops, that leaves about 2 minutes on the road for it to be a wash for riders. It’ll be close.
Off-peak, the Link headways will be longer and the buses faster (scheduled 10 minutes), so it’s going to be difficult for it to pencil out. However, for the large volume of 25, 43, and 48 riders this is pure win, though perhaps not as much as it could be.