Tesla added sensors, radar cameras to its cars in 2014 to power its Autopilot feature.

Tesla?s rate of data collection is climbing fast. The company is adding another million miles worth of data every 10 hours, according to Anderson, almost double the figure Tesla CEO Elon Musk cited last October.

Tesla?s Autopilot feature still ranks on the low-end of autonomy (one of Volvo?s engineers called Autopilot an ?unsupervised wannabe?). But Musk has been taking an incremental approach. His priority seems to be getting as many Tesla cars on the road as possible, streaming back data. ?When one car learns something, the whole fleet learns. This fleet learning is quite a powerful network effect,? Musk said in a press call last year. ?Any car company who doesn?t do this will not be able to have a good autonomous driving system.?

Volvo is planning to roll out its own self-driving test in 2017. BMW, Mercedes, GM and others are readying programs as well. But most players appear years away from reaching scale. Even Google, which launched its self-driving program in 2009, has only amassed just over 1.5 million miles on the road through its self-driving program, although admittedly it has taken the more challenging approach of building fully autonomous vehicles. Google augments its testing program by running new features against the entire simulated driving history of its 55-car fleet, and logs more than 3 million simulated miles per day without leaving the lab.

Tesla claims its strategy has taken it from the back of the pack to the forefront of self-driving technology. Given that almost every car company is now in this race, and you can even obtain kits to outfit existing vehicles, Tesla needs to be there. ?The ability to pull high-resolution data from these vehicles and to update the vehicles over the air is a significant part of what?s allowed us in 18 months to go from very behind the curve, to what is today one of the more advanced autonomous or semi-autonomous driving features,? Anderson said.