SAN FRANCISCO (CBS SF) – Toll cheating has dropped dramatically on the Bay Area’s bridges, possibly due to a new state law, according to officials.

For the past decade, $1 million in losses was typical each month, according to the Bay Area Toll Authority. But in May, that figure dropped to $250,000, a reduction of 75 percent.

Much of the drop has been credited to a new state law that went into effect this year where motorists with new vehicles get temporary plate numbers linked to a DMV database. That means drivers can no longer use unidentifiable dealer plates for months at a time.

Bridge officials also believe stepped up law enforcement may have encouraged long-term violators to replace dealer placards with legal plates.