In an effort to improve the speed and reliability of southbound buses along Interstate 5, late last year the Sound Transit Capital Committee approved funding for a bus-only shoulder lane between the Lynnwood Transit Center and the Mountlake Terrace Transit Center.

The Committee also approved funding for a feasibility study that would identify other potential opportunities to expand the program.

The I-5 bus-on-shoulder project is part of ST3’s Early Deliverables Program, a “series of improvements designed to improve existing transit services, reduce travel time through bus-on-shoulder operations and other related transit priority elements, and construct new park-and-ride facilities.”

ST says the 1.4-mile project is basically shovel ready, requiring minimal modifications including the addition of signage and lane striping, and improvements to pavement and drainage. For this project, ST is partnering with WSDOT, who has already completed the design and environmental review.

Construction on the project is anticipated to begin in the third quarter of 2018, with the operation of the lanes starting before the end of the year.

Only buses are allowed to use these lanes and are limited to maximum speeds of 35 mph or 10 mph above the adjacent traffic’s average speed, whichever is slower. According to WSDOT’s website, bus drivers who use the lanes will be specially trained.

Authorized transit buses will be able to use the inside southbound lane to bypass congestion in the adjacent HOV lanes. The shoulder lanes are expected to reduce bus travel times by 1-5 minutes, and potentially more depending on traffic congestion.

The project is estimated to cost roughly $265,000. As ST board member and King County Councilmember, Claudia Balducci, pointed out during the meeting, this project is “a relatively low-cost way to get people moving quickly.”

Eighteen Community Transit and Sound Transit bus routes will benefit from this project.

“Traffic congestion continues to get worse, and bus commuters often find themselves experiencing the same delays as drivers in their personal vehicles,” said Sound Transit Chief Executive Officer Peter Rogoff in a December press release. “While we continue work to bring light rail to Lynnwood and Federal Way in 2024, the bus-on-shoulder program will help improve the commute time for those who ride the bus into downtown from Snohomish County and other parts of our region.”

This project is just the first of the ST3 bus-on-shoulder lanes the agency is planning. During the Committee’s December meeting, board members also approved $375,000 in funding for a comprehensive feasibility study of the region’s highway system to identify other opportunities for operating buses in shoulder lanes. The study is anticipated to be completed by the end of 2018.

The ST3 package contains $102M in funding for the entire program. The transit agency hopes to have all bus-on-shoulder projects operating by 2024.

According to the approved motion, opportunities for additional bus-on-shoulder lanes exist along I-5, I-405, SR 518 and SR 167. I-90 will also be studied but, according to ST CEO Peter Rogoff, the ST3 package doesn’t allocate money for bus-on-shoulder projects in the East King County subarea.

Currently, bus shoulder lanes exist along southbound I-405 from the SR 527 on-ramp to the NE 195th Street off-ramp and from the SR 522 on-ramp to the NE 160th Street off-ramp.

WSDOT also recently launched a bus-on-shoulder pilot project in July 2017 along SR 14 between I-205 and Southeast 164th Avenue in Vancouver.