Ford just made a big bet on an expensive self-driving technology

Ford announced on Tuesday that it's joining China's Baidu and investing $150 million in Velodyne, a manufacture of a "Lidar" laser-radar system for self-driving cars.

Ford has been upping its commitment to Lidar since earlier this year, when at CES it announced it was increasing the number of self-driving prototype vehicles using the technology.

In January, the car maker said that it expected to have 30 self-driving cars undergoing testing in California, Arizona, and Michigan.

Velodyne's Lidar technology doesn't come without a cost. It's commonly accepted in the auto industry that Lidar is the most expensive path to a fully autonomous vehicle, largely because the combination of lasers and radars in spinning cylinders located on a car's roof takes the most advanced approach to removing the human driver from the picture.

Other automakers, most prominently Tesla, are using a combination of cheaper technologies, such as cameras and sensors, to enable self-driving systems.

Ford's move with with Velodyne is just the latest in a series of investments in Silicon Valley by Detroit. Ford put $182 million into Pivotal, a software firm that specializes in Big Data, and the automaker has plans to expand its Silicon Valley presence. General Motors invested $500 million in ride-sharing service Lyft and just closed its acquisition of Cruise Automation, a self-driving startup.

Fiat Chrysler Automobiles has a self-driving partnership with Google, and the general sense in Detroit is that the traditional auto industry, flush with cash amid a US sales boom, is now ideally positioned to invest proactively in the the technology firms that will make Motown relevant as the transportation landscape is transformed.