Within five years, Sound Transit expects to whip the 1st Street Northwest and A Street Northwest parking lot northwest of City Hall into its second parking garage in Auburn.

But the “Auburn Access Improvement Project” will also be the new digs for an array of access improvements for pedestrians, bicyclists and transit riders.

As Sound Transit officials told Auburn City Councilmembers on Monday night during a study session at Auburn City Hall, the constraining factor on those improvements and on city dreams is the $60 million Sound Transit has budgeted for the garage.

So, where the budget allows for the construction of 535 parking places and bike lockers and bike racks, stairs and elevators, it precludes bathrooms.

“As part of the project, we are looking at some non-motorized improvements, essentially improving pedestrian, bicycle and bus access to and from the Auburn Station. We’re having our design consultant look at some options, and once those have been evaluated, we’ll take a look at which projects we will be able to fund,” said Jason Suzaka, Sound Transit’s project manager for the Auburn station project.

Construction should start in 2021, and the garage open in 2023.

“Currently, we are in the conceptual engineering phase, at roughly about 10 percent design level,” Suzaka said. “We should complete this phase in the first quarter of 2019, and we’ll complete the environmental review process in the spring of 2019.”

Next spring, Sound Transit will share the results of the environmental review and other information at an open house in Auburn, and then the Sound Transit Board will decide on the project it intends to build shortly afterwards.

The wrinkle in Auburn’s situation is developer Jeff Oliphant’s private proposal to build a parking garage with perhaps twice the capacity at the old Mel’s Lumber site. Sound Transit has said it would consider that proposal after it had selected its preferred alternative. Oliphant was at Monday’s study session but did not comment.

On Nov. 16, 2017, Sound Transit’s Board identified the site as its preferred alternative among four options, which numbered the Ace Hardware store on West Main Street and the present station. The board also identified for Kent a parking garage site south of East James Street.

In addition, the board identified a proposed package of pedestrian, bicycle and transit access improvements at both locations, which it had prioritized as the most effective at improving non-motorized access to the stations.

To date, Sound Transit has held two open houses in Auburn, including one last Tuesday night at Auburn City Hall. The Transit Advisory Board has met four times to talk about the project.

Voters approved the Kent and Auburn Station Access Improvements projects in 2008. In 2010, however, the Sound Transit Board suspended funding because of the economic recession. It restored that funding in 2016.

Ridership on the popular Lakewood-to-Seattle Sounder line continues the growth it has experienced since service began from Tacoma nearly 18 years ago. Third-quarter weekday ridership grew 6.4 percent compared to the same period in 2016, and special service to Seahawks, Mariners and Sounders games remain the top travel choice for many sports fans.

Sounder commuter rail service operates 13 daily round-trip trains on its south line Monday through Friday at nine stations in Pierce and King counties.