Driverless vehicles may lead to traffic congestion in cities

Current trends such as digitalisation and the

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sharing economy will fundamentally change mobility in cities—on this most experts agree. In the future, public transport will be electric, customised, and readily available via smartphone. The first driverless taxi services have already been launched in Las Vegas and Phoenix in a bid to create a mobility system with significantly fewer vehicles, lower emissions, and at a lower cost (88 percent of the cost of a taxi ride in Zurich today pays for the driver). Previous studies encouraged these hopes: in 2014, researchers studying Singapore concluded that, with automated taxis, total demand for mobility could be met with just a third of the current vehicle fleet. In a study for Austin, the capital of the US state of Texas, researchers predicted that the fleet could be reduced by as much as 90 percent. Based on such studies, ridesharing companies such as Uber and Lyft sensed a huge market for their services, which will dispense with drivers in the future.

Simulations with broader scope

Kay Axhausen, Professor at ETH Zurich's Institute for Transport Planning and Systems, has now come to new conclusions in a study conducted on behalf of the Swiss Association of Transport Engineers and Experts (SVI) and financed by Switzerland's Federal Roads Office (FEDRO). His team simulated how Zurich's traffic volume might change if automated taxis were to be introduced at some point over the next two decades. The result was surprising: offering a ridesharing service would not decrease the number of private vehicles, and automated transport might even increase the number of kilometres driven.

In this form, the study is one of a kind in the world, as Axhausen explains: "Previous simulations mostly assumed ideal conditions, such as that every road user opts for an automated taxi provided waiting times are below a certain level." By contrast, his team developed a simulation that takes into account supply and demand as well as users' individual behaviour patterns. For a given fleet size, this generates a certain price per ride and a certain level of demand.

https://phys.org/news/2019-06-driverless-vehicles-traffic-congestion-cities.html