The number is up from 27 vehicles back in January this year. Uber previously operated a sizable fleet of self-driving cars in California, but its testing program has been suspended in the wake of a fatal crash in Arizona.
The new figures show that Apple still has the second-largest autonomous-car test fleet in California, which is arguably the epicenter of self-driving vehicle research.
Behind Apple is Alphabet's Waymo which now has 51 self-driving vehicles and Elon Musk-owned Tesla which has 39 cars.
This indicates a margin of error that's worth considering before rushing into fully self-driving trials; before the public can accept autonomous cars as a reliable alternative, companies need to gain its trust. Waymo, for example, used to have over 100 self-driving cars in the state before moving part of its fleet to Arizona and MI, where additional testing is now taking place.
Apple still hasn't publicly announced its plans when it comes to autonomous cars.
Nonetheless, it underlines how seriously Apple is taking this technology.
He added, "We sort of see autonomous cars as the mother of all AI projects It's probably one of the most hard AI projects actually to work on. It's probably one of the most hard AI projects actually to work on", Cook said last summer.
A newest list posted on DMV's website showed 53 pieces of Autonomous Vehicle Testing Permits (with a driver) had been permitted as of last Thursday, Xinhua reported on Monday.