California Governor Gavin Newsom on Saturday vetoed a bill that would have required all new vehicles sold in the state to feature a brief audiovisual warning every time the driver exceeded the posted speed limit by 10 mph.

Newsom's reasoning for knocking back the bill was concern a patchwork of regulations over vehicle safety would be created should California have its own rules separate to those set at the federal level, especially as The National Highway Traffic Safety is already evaluating the introduction of intelligent anti-speeding measures, the Associated Press reported.

Were the bill to pass, all new vehicles sold or leased in California would have required the warning system, with exceptions for certain trucks and motorcycles. Emergency vehicles would have also been exempt.

The bill, Senate Bill 961 introduced by Senator Scott Wiener, aimed to have the warning system introduced by the 2030 model year. The proposed system would rely on GPS information and a forward facing camera able to read posted speed limits, to determine the current speed limit.

A similar rule has already been introduced in the European Union where automakers have the choice of installing either an acoustic warning, a steering wheel vibration warning, an accelerator pedal that requires more force, or an actual speed-limiting feature.

A feature that limits a vehicle's speed based on the posted speed limit has previously been proposed by lawmakers in both California and New York, though hasn't gained much traction in either state.

Although some drivers may find such systems helpful, it's easy to see them evolving into something more draconian, especially if they are set up to pass information about a speeding vehicle onto authorities or insurance companies.