Synonyms for Roadblock:

n.

checkpoint, clue, agent provocateur, Amber alert, all-points bulletin, clean up, check, clampdown, APB, beat. drag, complication, problem, predicament, obstacle, embarrassment, brake, inconvenience. barrier (noun)
barricade.
cognition (noun)
barrier.
roadblock (noun)
barricade, barrier.

Other synonyms:

Other relevant words:
checkpoint, obstacle.