Logjam and Obstacle

Logjam noun - A crowded mass (as of cars) that impedes or blocks movement.

Obstacle and logjam are semantically related. in traffic jam topic. In some cases you can use "Obstacle" instead a noun "Logjam".

Obstacle noun - Something that makes movement or progress difficult.

Logjam and obstacle are semantically related. Sometimes you can use "Logjam" instead a noun "Obstacle".