The mother of all traffic jams was created in China on August 14, 2010. It lasted 12 days with a huge car panorama that stretched for more than 62 miles (100 km). A mini-economy of overpriced food, water, and cigarettes sprang up instantly.
The longest traffic jam in the world was in the China National Highway 110, between Hebei and Inner Mongolia. The traffic jam slowed down thousands of vehicles. As hungry and thirsty drivers sat in their cars for days, vendors came by to sell instant noodles at four times their usual price and water at ten times. Not caused by closure or natural disaster, this all-time tie-up cause was simply the result of too many vehicles clogging the road, particularly a bevy of heavy trucks carrying construction supplies into Beijing, ironically for road work that was intended to help ease congestion. Drivers were able to move their vehicles only 1 km (0.6 mi) per day.
More info&pic: https://www.mirror.co.uk/news/world-news/worlds-worst-traffic-jam-drone-6594560