Europe's largest railway network, the German operator Deutsche Bahn is reported to be working on driverless car technology which, it hopes, will solve the "last mile" problem for train passengers.Fortune.com reports that it plans to operate fleets of autonomous vehicles that could be ordered via an app, to be used to pick people up and bring them to stations.It quotes an interview the company's CEO Rüdiger Grube gave to the German newspaper Wirtshafts Woche.  In it, though, he didn't provide much detail, nor give a timeline on when the technology might be tested or widely deployed.Fortune says Grube said the company is also developing automated technology for its trains, "an advance that will eventually make human locomotive drivers obsolete".  But, it adds, this may take one or two decades.