Late last year, Google expressed its disappointment over the California Department of Motor Vehicles' restrictive draft proposals regarding self-driving cars. The proposed law stated that autonomous vehicles must have a steering wheel, and a licensed driver must be present to take over if the systems fail.

But now, following pressure from several tech groups, California is relaxing some of these regulations and has become the first state to allow autonomous vehicles on its roads without a human passenger inside.

Governor Jerry Brown signed off on the new rules, which only apply to a project at San Ramon's Bishop Ranch business park. French company Easymile's fully-autonomous, 12-seater buses move workers across the site, but as they cross some public roads, the updated was necessary.

Easymile's buses are already operating in Europe and Asia. They function without an operator, steering wheel, brakes, or accelerator. The revised law states that driverless vehicles must have a two-way communications link between passengers and a "remote operator." Easymile's shuttles must also meet federal standards and can't travel faster than 25 miles per hour.

The bill also covers the Concord Naval Weapons Station where Honda and Otto have been testing driverless vehicle technologies.

Under more proposed new rules, car manufacturers will be prohibited from advertising a vehicle as "autonomous" or "self-driving" if a human is responsible for controlling it. Tesla's autopilot feature, for example, couldn't be described using either of those terms.

Despite reportedly rebooting its long-rumored autonomous car project and laying off dozens of employees, Apple continues to test its Project Titan vehicles in a closed environment. Google, meanwhile, has been testing its self-driving cars on the roads of Texas for some time now, where there are no laws against autonomous vehicles without drivers, steering wheels or brakes. Both tech giants have reportedly shown an interest in the California Naval Station test site.