美国内华达州机动车管理部门近日向谷歌颁发了首个自动驾驶汽车牌照，以进一步检验此类车辆在实际道路驾驶中的性能。该汽车牌照为红色，上面用无限大符号∞来与其它车辆进行区分。如果进展顺利，自动驾驶汽车有望于三到五年内面市。届时，自动驾驶车辆的车牌将会定为绿色。

据介绍，自动驾驶汽车其实是用自动驾驶仪来控制车辆，不需要人类驾驶员有任何操作，也不会像人类驾驶员那样容易分神。安装在车顶和保险杠上的激光雷达可以随时监测车辆周边行人和车辆的情况，并会在各类障碍物与车辆之间形成一个虚拟的缓冲区域，以使车辆能够安全避开。

Department of Motor Vehicles officials said Monday they've issued Googlethe nation's first license to test self-driving cars on public streets.

Nevada drivers could soon be sharing the road with vehicles that don't needthem.

Department of Motor Vehicles officials said Monday they've issued Googlethe nation's first license to test self-driving cars on public streets, afterconducting demonstrations on the Las Vegas Strip and in Carson City that showthe car is as safe — or perhaps safer — than a human.

"It gets honked at more often because it's being safe," said Nevada DMVDirector Bruce Breslow.

Self-driving vehicle technology works like auto-pilot to guide a car — inthis case a modified Prius — with little or no intervention from a humanoperator. Laser radar mounted on the roof and in the grill detects pedestrians,cyclists and other vehicles, creating a virtual buffer zone around the obstaclesthat the car then avoids.

While some envision the robotic car dropping off its operator at the frontof the mall and hunting for a parking spot on its own, Breslow said not sofast.

Nevada's regulations require two people in the test cars at all times. Oneperson is behind the wheel, while the other person monitors a computer screenthat shows the car's planned route and keeps tabs on roadway hazards and trafficlights.

If there's a glitch, the human driver can override the autonomous auto witha tap on the brake or a hand on the steering wheel.

Last summer, Nevada Gov. Brian Sandoval took the car for a spin in andaround the state's quiet capital city. But Las Vegas Boulevard, where costumedsuperheroes routinely take the crosswalks and massive billboards angle for theattention of starry-eyed tourists, was perhaps best suited to test the car'smain purpose.

"They're designed to avoid distracted driving," Breslow said. "When you'reon the Strip and there's a huge truck with a three scantily clad women on theside, the car only sees a box."托福学习

So far, Google's applied to license three test vehicles. Breslow said thecars will display red plates and an infinity symbol to represent their status asvehicles of the future.

Once they're ready for the market — something Breslow guesses could come inthree to five years — the plates will be green.