The autonomous vehicle race just got spicier. Tesla Inc. (TSLA) CEO Elon Musk couldn't resist taking a shot at Alphabet Inc. (GOOGL) (GOOG) subsidiary Waymo over the weekend after the self-driving company announced a major expansion of its robotaxi operations.

Waymo Goes Big on Highways

Waymo made its move Wednesday with a blog post detailing plans to expand autonomous operations onto highways in three major markets: Phoenix, Arizona, and two California regions covering the San Francisco Bay Area and Los Angeles. This isn't just adding a few blocks here and there—we're talking about meaningful geographic expansion.

The most ambitious piece? Waymo's self-driving cabs will now cover the entire San Francisco peninsula, stretching all the way down to San Jose. That includes curbside pickup at San Jose Mineta International Airport, which is a significant operational milestone for any ride-hailing service.

Highway access fundamentally changes the game for autonomous vehicles. It increases range, improves efficiency, and makes the service actually useful for longer trips instead of just neighborhood cruising.

Musk's Trademark Response

Enter Elon Musk with his signature mix of competitiveness and sarcasm. His response to Waymo's announcement? Calling their fleet size "rookie numbers." Waymo currently operates 2,500 robotaxis spread across multiple cities, with substantial deployments in the SF Bay Area and Los Angeles.

That's not exactly small-time, but Musk clearly sees it differently. During Tesla's third-quarter earnings call last month, he outlined plans for robotaxis in Austin, Texas, to go fully driverless by the end of the year. Tesla's approach relies on a camera-based system rather than the lidar sensors Waymo uses.

Tesla currently runs robotaxis in Austin, including on highways, but with a human safety operator behind the wheel. Removing that operator would mark a major leap forward—assuming regulators and the technology cooperate. The question is whether Tesla can deliver on that timeline, something Musk hasn't always managed with his more ambitious predictions.

Game on, indeed.