John Markoff:

Cars that can park, brake at a sign of danger and navigate in traffic are on their way to dealers’ showrooms, turning science-fiction fantasies about consumer-owned self-driving vehicles into a new reality.

But as private investors have been pushing ahead to develop the systems needed for these new robotic machines, one crucial innovator has been largely out of the loop: the United States military.

The armed forces have lagged on deploying their own versions of unmanned road vehicles, despite goals to create new machines that could be used in place of “boots on the ground” in conflicts. Restrictions on government spending and technological challenges have left the military with virtually no chance of meeting the goal set by Congress to have a third of the military’s combat fleet consist of unmanned vehicles by 2015, military experts said.

The military’s failure to lead the way in self-driving ground vehicles is ironic, given that today’s commercial advances have their roots in research originally sponsored by Darpa, the Defense Advanced Research Projects Agency, the Pentagon’s advanced technology organization. A decade ago, Darpa offered a series of “grand challenges” to private researchers, which helped push the technology forward.