Supporters of the third phase of Sound Transit’s plan to extend its Link light rail into Everett, Tacoma and Redmond, dubbed ST3, know that the project’s $15 billion price tag may not be an easy sell to voters who will be asked to approve a package of tax increases to fund construction.

What would be more difficult, they say, is selling an $11 billion tax package that can only build a light rail system that’s 27 percent less than originally proposed.

The Republican-led state Senate’s tax package, passed last month, would give Sound Transit the authority to go to voters for approval of the ST3 plan, but limits the amount Sound Transit can seek from the transit district’s voters in Snohomish, King and Pierce counties to $11 billion, not the full $15 billion the transit agency says is needed for construction.

Sound Transit’s board of directors in December approved a general route for expansion into Everett, Tacoma and Redmond. By 2036, Everett’s route would extend Link from its Lynwood terminal to Everett Station and its transit services, with a loop that would serve Boeing and the other aerospace and manufacturing employers around Paine Field. But, said Paul Roberts, a Sound Transit board member and Everett City Council member, with routes also planned for Tacoma and Redmond, $11 billion, rather than $15 billion, would force cuts in the plan that would limit its service and effectiveness or could lead to infighting among communities as each sought to protect their piece of the system.

The ST3 expansion would be funded through a package of tax increases that would have to be approved in 2016 by Sound Transit district voters in the three counties. It would include increases to the Motor Vehicle Excise Tax, sales tax and property tax, that Sound Transit estimates would represent a median cost of about $78 for each adult annually. Median cost means half will pay less, half will pay more.

Sound Transit believes there is support for the full $15 million project and its taxes. Among the findings of a survey of potential voters that the transit agency released in January:

• 52 percent in Snohomish County and 56 percent overall see expansion of transit as the best way to alleviate traffic problems; 37 percent in the county favored expansion of roads and highways;
• 84 percent in Snohomish County supported expansion of light rail; 50 percent “strongly” and 34 percent “somewhat”;
• 75 percent in Snohomish County — 36 percent “strongly” and 39 percent “somewhat” — supported the $15 billion in taxes;
• 70 percent overall — 37 percent “strongly” and 33 percent “somewhat” — said they would support a $15 billion package of taxes;
• And when those polled were given the cost estimate of $78 per adult annually, the overall support remained strong at 70 percent, 37 percent “strongly,” 33 percent “somewhat.”

The Legislature was correct in giving Sound Transit the green light to go the voters to extend light rail but wrong to make the decision to cut the amount being sought. When the House and Senate negotiate a transportation budget, the ability to seek the full $15 billion should be restored Allow the voters to determine what they are willing to pay.