driver's role in such cars and govern how such cars perform in crashes where lives might be lost.

　　The proposal attempts to deal with what some call the"death valley"of autonomous vehicles: the grey area between semi-autonomous and fully driverless cars that could delay the driverless future.

　　Dobrindt wants three things: that a car always chooses property(财产)damage over personal injury;that it never distinguishes between humans based on age or race;and that if a human removes his or her hands from the driving wheel-to check email, say-the car's maker is responsible if there is a crash.

　　"The change to the road traffic law will permit fully automatic driving," says Dobrindt. It will put fully driverless cars on an equal legal footing to human drivers, he says.

　　Who is responsible for the operation of such vehicles is not clear among car makers, consumers and lawyers."The liability(法律责任)issue is the biggest one of them all," says Natasha Merat at the University of Leeds, UK.

　　An assumption behind UK insurance for driverless cars, introduced earlier this year, insists that a human "be watchful and monitoring the road" at every moment.

　　But that is not what many people have in mind when thinking of driverless cars."When you say 'driverless cars', people expect driverless cars," Merat says."You know-no driver."

　　Because of the confusion, Merat thinks some car makers will wait until vehicles can be fully automated without human operation.

　　Driverless cars may end up being a form of public transport rather than vehicles you own, says Ryan Calo at Stanford University, California. That is happening in the UK and Singapore, where government-provided driverless vehicles are being launched.

　　That would go down poorly in the US, however."The idea that the government would take over driverless cars and treat them as a public good would get absolutely nowhere here," says Calo.

1.What does the phrase "death valley" in Paragraph 2 refer to?