Evan Ackerman:

Last month, Hyundai quietly held its 2014 Future Automobile Technology Competition in South Korea. Out of 12 participating teams, four made it to the final round, which required the cars to navigate a test circuit. The autonomous cars were required to avoid obstacles, stop for pedestrians, obey traffic laws, and do all of the stuff that self-driving cars will have to be able to do if we’re ever going to be able to hop in, plug in a destination, and turn our attention elsewhere. The competition wasn’t anything that we haven’t seen before—except that during the second day of the competition, it rained.
 It looks like the team from KAIST’s Unmanned Systems Research Group wasn’t required to let its car traverse the course while it was actively raining, but it started out immediately after a heavy shower, on a wet road. The surface was slippery, certainly, but the real problem is that depending on the angle between the car, wet surfaces, and the sun, the car’s cameras can have a difficult time recognizing all kinds of things, including lane markings and street signs.