sound transit 3 was a ballot measure that was approved by voters during the november 2016 elections in king, pierce, and snohomish in washington. the $53.8 billion sound transit 3 plan will expand the existing link light rail system to the suburbs of tacoma, federal way, everett and issaquah, as well as the seattle neighborhoods of ballard and west seattle. the local portion of the measure would be partially funded by increases in sales tax, motor vehicle excise tax, and property tax.