SEATTLE -- Voters were approving, by 55-45 percent, the $54 billion Sound Transit 3 measure that would expand light rail in King, Pierce and Snohomish counties.
Votes will continue to be counted; more returns will be released Wednesday.
The project would build 62 more miles of light rail, provide additional park-and-ride spaces, add more bus-rapid transit and expand commuter train service.
Sound Transit estimates the average adult will pay $169 in taxes each year to fund the project.
Construction on the proposed light rail system would likely stretch out until 2041.
Large companies, labor unions, and contractors have helped bankroll the campaign for a yes vote.
Bellevue developer Kemper Freeman, who has long opposed light rail, wsa the top contributor to the no campaign.
Proponents say the fast-growing region needs more transportation capacity and a full ST3 network would provide 695,000 daily trips. Opponents balk at higher taxes and say self-driving cars and ride-hailing services could make light rail obsolete.