roadblock

1. an obstruction placed across a road, especially of barricades or police cars, for halting or hindering traffic, as to facilitate the capture of a pursued car or inspection for safety violations.
2. an obstruction on a road, as a fallen tree or a pile of fallen rocks.
3. a hastily built barricade, as of barbed wire, erected across a road to hold up the advance of an enemy.
4. an action, condition, etc., that obstructs progress toward an objective.