Google is significantly expanding its fleet of driverless vehicles, as the number of cars it is permitted to drive on public streets has more than doubled in last month. Presently, of all the driverless cars in California, Google now owns half of them, says a report from PC World.

Google's Driverless Car Fleet More Than Doubles In A Month

New permits for a new fleet of Google cars

By Wednesday, the internet firm held 48 permits for tdriverless vehicles compared to just 23 permits on May 15, according to data from the California’s Department of Motor Vehicles. California’s driver-less car fleet now totals 77, including two permits issued recently to  Mercedes-Benz. Tesla has twelve permits, meaning it operates the second-biggest fleet after Google.

Google reported that the recent 25 permits are for a new fleet of cars that are currently being tested on private roads. The internet firm said its two-seater car, with a top-speed of 25 miles per hour and apt for neighborhood driving, will hit public streets sometimes over the summer near the company’s headquarters in Mountain View.

Are Google driverless cars safe?

DMV data published Wednesday this week offers details on accidents involving driver-less cars in the state. Of note, only 306 drivers are licensed to operate autonomous vehicles in the state, of which 202 are associated with Google.

A regulation which came into existence in September 2014 mandates a report be made each time an autonomous car accident is reported. Although such accident reports are confidential in California, the DMV has decided to release the reports, treating autonomous vehicles as a special case.

As of Thursday, of the six reports filed, five were related to Google cars, while the last involved a car operated by Delphi Automotive. Of those five, four were already disclosed by Google earlier this month when it issued a first of its kind monthly report on driverless car incidents. The fifth accident was not reported by Google as it occurred in June, which is after the latest report from the internet firm.

Google highlighted that all the accidents took place because of human error, either by the driver of the autonomous car or by another driver. This fact was noted by Google Co-founder Sergey Brin, who in a recent shareholder meeting said “I’m very proud of the record of our cars,” adding “Our goal is to beat human drivers, and nothing can be a perfect vehicle.”