San Diego, CALIF.-Measure A is a proposal from the San Diego Association of Governments (SANDAG) that would create a half-cent sales tax to fund transportation and infrastructure projects throughout the county.

The measure would raise about $18 billion over the next 40 years and legally bind SANDAG to finish a number of projects within the next 15 years.

Some of those projects include a new Coaster station at the Del Mar Fairgrounds, and the Purple Trolley line from San Ysidro to Kearny Mesa.

It would also make funds available for a commitment San Diego made to protect endangered species on preserved lands – an agreement it hasn’t figured out how to pay for.

The tax money would pay for some of the $204 billion worth of projects SANDAG has positioned for its regional transportation plan.

Different measures were floated by the agency earlier this year and leveraged public transit projects against local infrastructure. In July, SANDAG’s board approved a combination of the two to put on the ballot.

The plan has support from Councilman Todd Gloria, Chula Vista Mayor Mary Salas, and the San Diego Chamber of Commerce. Mayor Kevin Faulconer and a coalition of labor and environmentalists oppose it.