Fig. 4: Identifying non-equilibrium surge dynamics and anomalous supply shortages.

Repeated price surges similar to those observed at DCA (compare Fig. 3e) emerge in locations across the globe (America, Asia, and Europe) and independent of type of origin (airport, train station, and other prominent locations). The surge dynamics at the six locations identified in Fig. 3a is qualitatively and statistically similar to DCA. In particular, sustained periods with non-zero surge fee likely reflect a real supply–demand imbalance at that time while periods with repeated surge peaks are characteristic for price surges induced by artificial supply shortages (e.g. Warsaw evening, Montreal evening, Chicago evening, New York City afternoon and evening).