A traffic jam by which no vehicular motion is achievable, specifically one caused by the obstruction of crucial intersections within a grid of roads.
an entire not enough motion or progress leading to a backup or stagnation: "the governmental gridlock that prevented ... the President and Congress from moving expeditiously to slice the spending plan” ( Robert D. Hormats).
A condition of total, interlocking traffic congestion on the streets or highways of a crowded town, which nobody is able to move because everybody is in another person's method.
On an inferior scale: the situation which automobiles enter a signal-controlled intersection too late through the green light period, as they are incapable of clear the intersection (because of obstruction in the next block) whenever light transforms red, therefore blocking the mix traffic when it is their particular move to get. Duplicated at enough intersections, this event can lead to citywide gridlock.
Figuratively by expansion, any paralysis of a complex system because severe obstruction, dispute, or deadlock.