Quetta Road, the only thoroughfare connecting Balochistan to Punjab, has been closed, with hundreds of trucks and passengers stuck in the mountainous region, SAMAA TV reported Wednesday.
Passengers travelling between Punjab and Balochistan have been struck in a massive gridlock near Dera Ismail Khan since Tuesday night.
If the highway closure continues, business in both provinces may be suspended.
Hundreds of truck drivers are currently stuck at Rakhi Gaj, where the Quetta Road is closed due to construction of a bridge.
Miles-long queues of trucks can be seen on both sides of the road.
Fruit, meat, poultry and vegetables loaded in the trucks is also at risk of spoiling while waiting for the traffic to clear.
National Highway Authority officials said a temporary closure of the road at Rakhi Gaj triggered the blockade on the curvy mountainous highway.
The road had not been opened till the filing of this report.