Protestors kneeling on the road brought traffic to a complete standstill at Route 29 around 12:30 p.m. in Silver Spring, leading to the arrest of 14 people.
Some activists say that the action of stopping traffic actually contributed to making the climate worse.
The highway reopened around 1:45 p.m., as the 14 protestors were arrested for disturbing the peace, WTOP said.
Some drivers fumed that aside from polluting the air, bringing traffic to a standstill was unproductive.
Click here to follow Daily Voice Edison and receive free news updates.