Here's how Metro's proposed sales tax could be recalled

Los Angeles County's transit agency will ask voters this November to approve a new sales tax increase to raise billions of dollars for transportation projects, but if voters allow it, they could later roll it back.

Provisions in the proposal would help keep the agency accountable by allowing voters to recall the tax through the initiative process.

Metro's latest proposal calls for a new half-cent sales tax and an extension of the Measure R half-cent sales tax; both would remain in place until voters change their minds, if they ever do.

But how exactly can a recall of a sales tax happen? It turns out the same state law that allows local governments to place tax increases on the ballot also allows voters to repeal them.

Recall sponsors could gather the required signatures for a ballot measure calling for a rollback of the tax and that measure once qualified would be put to voters in a future election.

Metro would also be subject to an oversight panel as part of the proposal, a previous version of which would raise $120 billion in transportation funding for projects that include Sepulveda Pass toll lanes.

"We are paying very careful attention to this and the measure will be closely monitored by an independent oversight panel as Measure R is," said Metro spokeswoman Kim Upton.

Measure R, the half-cent sales tax that voters approved in 2008, funds construction of five rail lines, highways and bus improvements.

The oversight panel would conduct yearly audits of Metro spending and provide public reports on how closely the agency keeps to its plan.

The Metro Board would also be obligated to perform a full review of the spending and timeline every 10 years.