KATHMANDU: The complete closure of the Prithvi Highway, a key road link between Kathmandu and the western and central parts of the country, is expected to significantly increase traffic on the BP Highway, particularly from eastern hill and Tarai districts.

The Prithvi Highway was completely disrupted after flooding in the Trishuli River on Sunday morning washed away and damaged sections of the road, including at Krishnabhir and several other locations.

With the major highway out of operation, night buses and freight vehicles travelling to Kathmandu from eastern and Tarai districts are expected to divert towards the BP Highway. The Road Division Bhaktapur has warned that the alternative routes could face significant pressure.

Suman Yogesh, division chief and senior divisional engineer at the Road Division Bhaktapur, said the closure of the Prithvi Highway would also increase traffic on the Kanti Lokpath and Tribhuvan Highway. However, he said neither route has sufficient capacity to handle the additional passenger and freight traffic.

“Both passenger and freight vehicles coming from different directions cannot be handled by these two highways. Therefore, we expect traffic from large night buses and freight vehicles travelling from the eastern and Tarai districts to increase on the BP Highway,” Yogesh said.

Narrow sections pose a challenge

The BP Highway itself is undergoing reconstruction following damage caused by earlier floods. The increased movement of large night buses, freight trucks and LPG tankers could therefore create serious traffic-management and safety challenges.

According to Yogesh, the sections from Dhulikhel to Bhakundebesi in Kavrepalanchok and Khurkot–Chiyabari in Sindhuli contain several narrow bends where large vehicles could face difficulties.

While the highway can accommodate increased movement of smaller vehicles during the day, Yogesh said it does not have sufficient capacity to handle a large number of heavy vehicles at the same time.

“We have experienced traffic jams lasting for hours even when some large construction equipment was transported for reconstruction work. Therefore, operating large vehicles on the BP Highway during the daytime is not feasible,” he said.

Large vehicles may be managed at night

The road authorities are considering operating large night buses and freight vehicles during nighttime by temporarily holding other traffic if necessary.

Yogesh said the daytime traffic of smaller vehicles could be managed, while large vehicles could be given controlled access at night.

The same approach could be considered for LPG tankers if their movement becomes necessary. In such a case, reconstruction work could be temporarily halted and the old track used to facilitate tanker movement at night.

“If LPG tankers have to operate, we can temporarily stop the highway work and allow them to use the old track at night,” Yogesh said.

However, authorities plan to have tanker drivers inspect the route on the ground before deciding whether LPG tankers can safely operate on the highway.

Prithvi Highway could remain closed for more than a month

The damaged sections of the Prithvi Highway are unlikely to reopen immediately. Yogesh said it could take more than a month to restore the highway, depending on the extent of damage and the reconstruction work required.

The prolonged disruption could put additional pressure on Kathmandu’s supply chain, particularly for passenger transport, freight movement and the delivery of essential commodities and LPG.

BP Highway was developed as an alternative route

The idea of developing the Banepa–Sindhuli–Bardibas road as an alternative connection between Kathmandu and the Tarai dates back to around 1960 BS. Although construction had begun in some sections, the project was later suspended following the construction of the Tribhuvan Highway.

The need for an alternative route became more evident after severe rainfall in 2050 BS caused extensive damage to both the Tribhuvan Highway and Prithvi Highway, disrupting Kathmandu’s road connectivity with other parts of the country.

The government subsequently developed the route with grant assistance from the Japanese government, with construction beginning in fiscal year 2053/54. Japan formally handed over the highway to the Government of Nepal in 2072 BS.

With the Prithvi Highway now out of operation, the BP Highway is once again emerging as a critical alternative route-but its ongoing reconstruction and limited capacity could make handling the additional traffic a major challenge.