1 PM: One more team has scratched—Germany's CarOLO—but the remaining six contenders are looking strong. The three current front-runners are Stanford, Virginia Tech, and Carnegie Mellon's Tartan Racing. All have completed two of the three prescribed missions, meaning they're about two-thirds done with the race. The Cornell and MIT vehicles were locked together side-to-side for several minutes, Ben Hur chariot-style, but both managed to disentangle themselves and are motoring along again.

It's difficult to describe a self-driving vehicle to someone who's never seen the phenomenon firsthand, but suffice it to say these cars move in a way that's both wobbly and overly meticulous, like they're being steered by phantom drivers still a little unsure of their ability. (Trust me, I know that driving style—I nearly failed my road test as a teenager for being too slow and tentative behind the wheel.)—Elizabeth Svoboda