Going nowhere fast Benjamin A Peterso/Getty

Hackers could one day gridlock Manhattan by infiltrating smart cars making up 10 per cent of all vehicles being driven in the New York City borough.

Although car hacking is rare, it can be done, giving attackers complete remote control of the vehicle. “We wanted to get a sense of the worst-case scenario,” says Skanda Vivek at the Georgia Institute of Technology in Atlanta.

He and his colleagues modelled what would happen if cars all over Manhattan suddenly came to a stop. Their simulation halted vehicles at random on straight roads with between two and …