the.com/traffic jam
Thousands of people independently deciding to sit still together.
means A long line of vehicles stuck moving slowly or not at all, usually because there are too many of them for the road to handle.
from "Traffic" entered English around the 16th century via French and Italian trafico, originally meaning trade or commerce — the movement of goods, not cars. It shifted to mean the movement of vehicles and people as roads filled up with them. "Jam" comes from the verb meaning to wedge tightly or crush into a space, a word with origins probably imitative of the squeezing sound or sensation. The two meanings pressed together make sense: traffic jam, trade squeezed to a halt, literally commerce wedged solid on asphalt.
- phantom cause
- Often no accident, just one driver braking too hard
- wave physics
- Jams travel backward through traffic like a slow-motion ripple
- math fix
- Everyone matching speed instead of surging could erase most jams
- first recorded
- Jams predate cars, Roman cart gridlock banned by Julius Caesar