  Digital technology is fundamentally transforming human mobility. Route
choices in particular are greatly affected by the availability of traffic data,
increased connectivity of data sources and cheap access to computational
resources. Digital routing technologies promise more efficient route choices
for the individual and a reduction of congestion for cities. Yet, it is unclear
how widespread adoption of such technologies actually alters the collective
traffic flow dynamics on complex street networks. Here, we answer this question
for the dynamics of urban commuting under digital route choice support.
Building on the class of congestion games we study the evolution of commuting
behavior as a fraction of the population relies on, but also contributes to,
crowdsourced traffic information. The remainder of the population makes their
route choices based on personal experience. We show how digital route choice
support may cause a separation of commuter flows into technology and
non-technology users along different routes. This collective behavior may fuel
systemic inefficiencies and lead to an increase of congestion as a consequence.
These results highlight new research directions in the field of algorithmic
design of route choice decision support protocols to help fight congestion,
emissions and other systemic inefficiencies in the course of increasing
urbanization and digitization.
