SEATTLE — The Sound Transit Board of directors is honing its pitch to voters for a massive expansion plan, including getting light rail to Everett by 2036 or earlier.

The board Thursday directed staff to finish details for the Sound Transit 3 ballot proposal.

The board expects to take final action at its June 23 meeting to send the $54 billion package to voters this fall.

Everett Mayor Ray Stephanson will be urging people to support the Nov. 8 ballot measure known as ST3 for short.

“If we don’t have voter success this year, we won’t have another swing at this for four more years,” Stephanson said.

The latest version of ST3 would build a total of 62 new miles of light rail with 37 new stations.

Sound Transit staff say that the higher sales tax, property tax and car-tab fees to pay for the work would cost the average adult taxpayer about $200 more per year.

Snohomish County Executive Dave Somers said the long-term transit commitment is necessary to help accommodate the 200,000 people expected to be added to the county’s population over the next 20 years.

“If we don’t do this, what do we do?” Somers said.

Since the ST3 draft plan was announced March 24, Somers and the other two Sound Transit board members from Snohomish County have been working to shorten the original 25-year timeline for delivering light rail to Everett.

Sound Transit already is on course to build the line north to Mountlake Terrace and Lynnwood by 2023.

For local political leaders, one aspect of the route was non-negotiable: serving the industrial area around Paine Field and the Boeing Co.’s Everett plant.

To speed things up, they agreed to an alignment that would follow Highway 526 and I-5 between Paine Field and Everett Station. That’s supposed to save time and money over a path along Evergeen Way, which would entail more complicated right-of-way acquisition and other expenses. The new plan also makes a station at Highway 99 and Airport Road provisional, rather than a definite part of the proposal.

Other stations would be near Alderwood mall, the Ash Way Park-and-Ride, 128th Street near I-5, Paine Field and Evergeen Way near Highway 526. The whole addition would open at once, not in stages.

Elected leaders in Snohomish County, Everett and Lynnwood have passed resolutions promising to speed up permit processing on Sound Transit 3 projects.

“I want to be clear that this is not doing environmental work with a wink and a nod,” said Everett City Councilman Paul Roberts, a Sound Transit board member and the city’s former planning director.

The agreements will help resolve alignment questions beforehand, among other issues.

“We don’t want to oversell this, but we think we can shave a year, possibly two years, off this process,” Stephanson said.

The mayor and others hope that federal funding for the segment could further accelerate the timetable.

If the measure passes, Sound Transit promises to deliver more than light rail.

It would aim to bring a bus rapid-transit line to I-405 between Lynnwood and Burien by 2024. A separate bus rapid-transit line would serve the Highway 522 corridor from Woodinville to north Seattle. The plan calls for more parking at the Edmonds and Mukilteo Sounder stations.

Another early benefit of ST3 would be increasing the use of freeway shoulders for buses where it’s possible. Buses already use the shoulders as travel lanes on parts of the I-405 corridor.

Elsewhere in the region, ST3 promises to deliver light rail to West Seattle and Tacoma by 2030 and to Ballard by 2035

Noah Haglund: 425-339-3465; nhaglund@heraldnet.com. Twitter: @NWhaglund.