GPS Mapping Makes Traffic Worse
https://www.theatlantic.com/technology/archive/2018/03/mapping-apps-and-the-price-of-anarchy/555551/
Alexis Madrigal from The Atlantic reports on research at UC Berkeley’s Institute of Transportation Studies (UCITS), which suggested that mobile GPS mapping apps are causing traffic patterns to be further from the social optimum. The research involved using a commercial-transportation simulator, Aimsun, to compare freeway congestion when zero and twenty percent of drivers use routing apps. The finding was that in response to a traffic incident, the simulation with twenty percent of drivers using routing apps were much slower to recover from the incident. Specifically, cars were rerouted off the freeway, resulting in congestion at off-ramps, intersections, and even all along the freeway itself. So, the research suggests that in addition to routing apps congesting the freeway, the side streets and intersections also become congested. The director of UCITS, Alexandre Bayen, suggested a solution for improving the apps – intentionally spreading out drivers on different routes rather than putting each driver on the shortest path. However, this strategy requires collaboration among mapping apps.
This phenomenon of GPS mapping apps causing higher traffic congestion can be explained by Braess’ Paradox, as discussed in class. Before the age of GPS, most people didn’t know road networks well enough to take any back roads. Consequently, most people took the freeways, which are built to handle bulk traffic. With the introduction of GPS, back road routes suddenly became accessible to everyone, allowing drivers to always take the shortest route, yet resulting in every driver to have longer travel times. This is essentially Braess’ Paradox, which says that adding resources to a transportation network can sometimes hurt the Nash Equilibrium of the network.