bumper to bumper - vehicles that are bumper to bumper are in a line one after another and are moving very slowly or stopped.
We were caught in bumper-to-bumper traffic for over an hour.
(always before noun)
bumper-to-bumper
adjective (used of car traffic) moving slowly and close together US, 1938
bumper to bumper
Very close together. Typically said of traffic that is moving very slowly or not at all. The cars on the highway are bumper to bumper right now—there's no way we'll get there on time.
bumper-to-bumper
1 very close together, as cars in a traffic jam. 2 (chiefly of an insurance policy) comprehensive; all-inclusive.