Traffic Congestion

How traffic signals actually optimize intersection flow, explained

This 2019 explainer breaks down how traffic signals manage competing streams of cars, bikes and pedestrians at urban intersections, describing them as the key bottleneck limiting a roadway's overall capacity. It draws an analogy between city road networks and human anatomy, showing how arterial roads rely on at-grade, signal-controlled intersections rather than ramps or overpasses to regulate right-of-way.

practical.engineering · 2026-09-21

Google Research Tests Traffic-Spreading Algorithm on Maps Users in 10 U.S. Cities

Google's research division ran an experiment rerouting a small subset of Google Maps drivers across 10 U.S. cities, including San Francisco, Los Angeles, Seattle and Chicago, spreading vehicles across more routes instead of funneling them onto the fastest-looking path. The published results, which appeared in Nature Cities, showed average speeds rose about 2% and travel times shortened by 0.7%, with highway-focused rerouting in Los Angeles boosting speeds by as much as 4.6%.

tech.slashdot.org · 2026-09-08