A shortage of bitumen, triggered by supply disruptions linked to the US-Iran tensions, has brought asphalt works to a halt across Nepal and severely affected major road projects during the peak construction season.

Officials say the disruption has hit national pride and strategic projects and raised concerns that annual targets for road surfacing will not be met. While a few projects continue limited work using existing stock, most have stopped asphalt work altogether.

“There is a shortage of bitumen in the market, and construction material costs have also increased,” said Bijay Jaisi, director general of the Department of Roads. “This has had a major impact on projects nationwide. Discussions are ongoing at the department and ministry to soon find a way out.”

Among the affected are flagship projects such as the Mid-Hill Highway, Postal (Hulaki) Highway, Koshi Corridor, Kaligandaki Corridor, Karnali Corridor and the Kathmandu-Tarai Expressway. Asphalt work has also been halted on the Madan Bhandari Highway, Nagdhunga-Mugling road, Jamune-Pokhara road and the Suryabinayak-Dhulikhel section.

The impact is visible on the busy Nagdhunga-Mugling stretch, on which more than 12,000 vehicles pass daily. Asphalt work has stopped after bitumen stocks ran out. The 94.66-kilometre upgrade project, divided into three sections, is near complete in several parts.

“In the Nagdhunga-Naubise section, the second layer of asphalt had been completed and we were preparing to lay the final layer,” said Keshav Prasad Ojha, chief of the eastern section of the project. “But only six kilometres of the final layer could be completed before work stopped due to the shortage.”

In the Naubise-Malekhu section, old road surfaces have been removed in preparation for resurfacing, and stretches have been left exposed.

Around 5,000 tonnes of bitumen are needed to resume work, said Ojha.

In the Malekhu-Mugling stretch, asphalt works in areas such as Bishaltar and Majhimtar have also stalled.

The resistance of local people has further complicated the situation. Although a permission to extract construction materials from Lamebagar in Malekhu was granted after environmental impact assessment, protests have delayed supply.

“The shortage of bitumen and rising diesel prices have affected progress,” said Sajana Adhikari, chief of the western section of Nagdhunga-Mungling road project. “We had aimed to asphalt 20 kilometres this fiscal year, but have managed only five kilometres so far,” she added. Overall progress in the western section stands at 42.5 percent. With roads dug up in several locations and the monsoon approaching, officials warn of increased risks of landslides and traffic disruption.

The problem extends beyond this project. The Koshi Corridor, a 162-kilometre route linking Basantapur in Tehrathum to the northern border at Kimathanka, is only 46 percent complete despite multiple deadline extensions. Asphalt works there have also stopped.

Similarly, the Kaligandaki Corridor, another national pride project which connects Gaindakot to Korala via Beni and Jomsom, has also been halted. “Asphalt work was under way, but has now stopped due to the bitumen shortage,” said project director Dharmendra Kumar Jha. The project has achieved just over 82 percent progress.

The Karnali Corridor, another strategic north-south route, remains far behind schedule, with only 20.5 percent progress. Rising diesel prices have slowed work further. “Asphalt works on projects such as the Tamor Corridor, Saljhandi-Sandhikharka road and Kanti Highway have also been affected,” said Jha.

The Mid-Hill Highway, one of the country’s most ambitious projects, has also been hit. Nearly two decades after construction began, the project is only 82 percent complete. “This is the right season for asphalt work, but the shortage has affected progress,” said project director Buddha Ratna Tuladhar. “We had set a target of 75 kilometres this fiscal year, but only 23 kilometres have been completed so far.”

The Postal Highway, designed to connect the Tarai region from east to west, faces similar setbacks. Director Kuber Nepali said asphalt work has stopped in districts including Dhangadhi, Kanchanpur, Madi (in Chitwan), Morang and Siraha. “We had targeted 76 kilometres this year, but will struggle to exceed 50 kilometres unless supply improves,” he said.

The project, launched in 2009-10, is 75 percent complete, but delays caused by funding constraints and policy issues have been widely reported in recent years.

Work on the Madan Bhandari Highway has also slowed, although the project has already exceeded its initial annual target. “We had planned to asphalt 30 kilometres and have completed 31 kilometres,” said project director Deep Barahi. “However, the pace has slowed due to bitumen shortages and rising fuel costs.” He added that asphalt work has now stopped in Surkhet, Gulmi and Damak. “We could have completed an additional 10 kilometres this year if supplies were available,” he said.

The much-anticipated Kathmandu-Tarai Expressway, being constructed by the Nepali Army, has also been affected. The project had aimed to complete six kilometres of asphalt work this fiscal year, but progress has slowed due to supply constraints. The Army said that rising prices of construction materials have also affected other works.

Various road projects funded by development partners are not immune. Under the Asian Development Bank-supported road expansion programme, work on the Kamala-Kanchanpur section has slowed, with overall progress at 67 percent. Rising diesel prices have also affected the Kakadbhitta-Laukahi road project.

“Work was progressing in the Kamala-Kanchanpur section, but rising fuel costs have reduced the pace,” said Chudaraj Dhakal, project director at the Asian Development Bank Project Directorate. “The impact is also visible in projects such as Jamune-Pokhara and Narayanghat-Butwal.”

Contractors say the shortage of bitumen and rising costs of petroleum products and construction materials have forced them to slow work. Officials warn that without immediate improvements in supply, project timelines will slip further. As the monsoon season approaches, concerns are growing over road safety and prolonged disruption.