It takes vehicles about two hours to cross just a two-kilometre stretch of Dhaka-Tangail highway near Rasulpur and Pungli, said transport workers.
The condition of the road there is appalling, they said, adding that tailbacks of hundreds of vehicles are common.
Though the road has been in a battered condition for the last couple of months, the authorities concerned are in no hurry to fix it properly, alleged transport workers, and traffic and highway police.
This correspondent yesterday saw several hundred vehicles, including buses and trucks, stuck on the two-kilometre stretch.
The patch repairs being done by the Roads and Highways Department are also deteriorating the traffic situation. The RHD has set up a contraflow there.
Traffic and highway policemen were seen struggling to ease the congestion.
Traffic Sergeant SM Shahid told this correspondent that gridlocks were a daily phenomenon for the last few months as the road was in a bad shape and expansion work of Joydevpur-Chandra-Tangail-Elenga road was going on.
"Numerous potholes, some of them really big, have appeared on the road, turning the road almost unusable for vehicular movement," he said.
"If the road is not repaired properly within the next few weeks, it will be a serious problem before Eid-ul-Azha," he added.
Masud Rana, driver of a bus heading for Rajshahi, said his vehicle gets stuck for a few hours in the traffic jam every day.
"Dealing with queues of hundreds of vehicles every day has become difficult," said Sazedul Islam, a traffic inspector of Tangail police, adding, "The authorities of four-lane project and the Roads and Highways Department are now blaming each other for such a bad condition of the road."
Engineer Sheikh Mohammad Shaharul Amin, deputy manager of SASEC Road Connectivity Project: Improvement of Joydevpur-Chandra-Tangail-Elenga Road to a Four-Lane Highway, said they were not responsible for the problem and that they already completed several hundred metres of road construction work in the area.
"The Roads and Highways Department is responsible for the rundown part of the road," he added.
"We are not denying our responsibilities. Repair work is going on," said Abdul Hakim, a sub-divisional engineer of the RHD in Tangail.
"Nonstop heavy rain is not only damaging the road badly, but also hampering the repair work," he said, adding that as a massive development work (four-lane project) was going on, people would have to face some difficulties in the next three to four months.