the.com/intersection design
the art of making four directions of traffic pretend they're taking turns nicely.
means the engineering discipline of arranging roads, signals, and geometry so vehicles and pedestrians cross paths without colliding.
from emerged with mass car ownership in the 1920s, when cities realized painted lines and cops on boxes couldn't keep up with traffic volume, forcing engineers to formalize geometry, timing, and sightlines into a science.
roundabouts cutfatal crashes drop roughly 90 percent versus signals
left turnscause disproportionate crashes, so ups routes avoid them
diverging diamondbriefly sends cars to the wrong side, on purpose
protected intersectionscorner islands shield cyclists from turning trucks
for instance
magic roundabout swindon — five mini-roundabouts orbiting one big one since 1972
arc de triomphe circle — twelve avenues meet with famously no lane markings
tokyo shibuya crossing — up to 3000 pedestrians cross at once, every two minutes