Google's Waymo is leading the self-driving car race

Google's self-driving car project--now known as Waymo--has put plenty of miles on the odometer. In fact, since 2009, the company's autonomous fleet has traveled 2.3 million miles without assistance from their human companions.

All that work is paying big dividends, according to new data from the California Department of Motor Vehicles.

California has become a popular site for companies to test their self-driving technology on public roads. It's a big state with varied terrain, and of course, it's got a huge tech community on-hand to perfect autonomous software.

However, companies have to secure permits from the state's DMV before they can test self-driving vehicles on public roads. And to maintain those permits, companies have to submit annual reports about their self-driving cars.

The reports detail how many miles autonomous cars traveled in self-driving mode on California's public roads. They also list the number of times that autonomous software disengaged--either of its own accord (because, for example, it didn't know how to interpret and maneuver through a given environment) or at the discretion of the human driver (because, for example, the software didn't recognize a problem, like an obstacle in the road or another vehicle).

California's DMV recently posted annual reports from automakers and others who've been testing self-driving cars in the state. Based on the data submitted, it's pretty clear that Waymo is way ahead of the competition.

Here's a breakdown for each company that submitted a report. We've highlighted the best (Waymo) and worst (Bosch) of the disengagement rates:

December 2015 - November 2016 unless otherwise noted

BMW: 638 miles, 1 disengagement (1 per 638 miles)

Bosch: 983 miles, 1442 disengagements (1 per 0.68 miles)

General Motors: (June 2015-November 2016): 10,015.21 miles, 284 disengagements (1 per 35.26 miles)

Delphi: 3,125.3 miles, 178 disengagements (1 per 17.56 miles)

Ford: 590 miles, 3 disengagements (1 per 196.67 miles)

Google/Waymo: 635,868 miles, 124 disengagements (1 per 5,127.97 miles)

Honda: No tests on public roads (n/a)

Mercedes-Benz: 673.42 miles, 336 disengagements (1 per 2 miles)

Nissan: 4,099 miles, 28 disengagements (1 per 146.39 miles)

Tesla: 550 miles, 172 disengagements (1 per 3.2 miles)

Volkswagen: No tests on public roads (n/a)

What makes Waymo's stats even more impressive is the fact that they improved dramatically from the previous year. In its 2015 report, the company said that it's vehicles had traveled 424,331 miles in self-driving mode with 341 disengagements, or one per 1,244.37 miles. It's current rate is about four times better.

Also: is anyone else alarmed that Tesla's disengagement rate is so high? After all, this the company that began installing fully autonomous software on new vehicles last year, with plans to begin activating it within the next six months