When the Carola Bridge in Dresden collapsed unexpectedly, the city's traffic network did what network theory predicts: it redistributed. The Albert Bridge absorbed an 81% increase in daily volume. The Marien Bridge took the rest. Peak hours on critical links stretched to 250 minutes. The local redistribution was textbook.
But Ijaradar, Xie, Wei, Pape, Körner, and Wang (arXiv:2603.19947) find something the redistribution model misses. Roughly 8,000 vehicles per day simply stopped crossing the Elbe. They didn't find another route. They disappeared.
Where did they go? Park-and-ride usage surged 188%. Some drivers switched to public transit. Others presumably rearranged their trips to avoid the crossing entirely — working from home, choosing different destinations, consolidating errands. The bridge was carrying demand that existed partly because the bridge existed. Remove the infrastructure, and some of the demand it served dissolves rather than relocating.
This is the reverse of induced demand, the well-documented phenomenon where adding road capacity generates new traffic. Here, removing capacity destroys existing traffic. The network isn't a fixed-demand system that routes flow optimally. It's a system where the infrastructure participates in creating the demand it carries. The bridge wasn't just serving 8,000 trips. It was causing them.