A situation where roads in a town become so blocked by cars that is impossible for any traffic to move. (Cambridge Dictionary)
A situation in which no progress can be made. (Cambridge Dictionary)
The stoppage of free vehicular movement in an urban area because key intersections are blocked by traffic. (Dictionary.com)
The blocking of an intersection by vehicular traffic entering the intersection but unable to pass through it. (Dictionary.com)
Gridlock in Washington won’t be good for a stock market thirsty for more tax cuts and spending.
Buyers in Downtown Los Angeles escape the gridlock.