Roads: Preliminary findings of the 55km Panbang to Nganglam highway has found that heavy trucks and geological factors are the two reasons for the road disintegrating, according to the expert team that carried out the investigation.

The investigation, which was carried out from February 13 to 15 also showed that quality was not compromised as per a laboratory test and that the contractors constructed and paved the road as per the required design and specifications.

A team of experts from Department of Roads (DoR) conducted the investigation after Prime Minister Tshering Tobgay called for it. The highway despite being blacktopped less than two years ago is already pockmarked with potholes and cracks have developed at different points.

The DoR chief engineer based in Trongsa, Taujay Chedup said heavy vehicles carried loads in excess of the carrying capacity of the road, which is 16 metric tonnes.

“The findings showed the trucks carry almost 20 metric tonnes including the truck’s weight, and 10 wheelers carry almost 30 metric tonnes,” Taujay Chedup said. “The loads were not controlled and trucks started ferrying even before the highway was completed.”

More than 300 trucks use the highway daily in addition to medium and light vehicles. The load of the trucks are now being monitored.

Taujay Chedup said it was also found that certain areas were geographically marshy and contained high levels of moisture especially between the 25km to 47km points from the Nganglam side. He pointed out that potholes and cracks had appeared in these marshy areas.

“Since these areas face the north zone, it receives less sunlight and it could be worse in summer,” he added. “The area was still wet even during the field investigation.”

The road from the Panbang side, between 12km to 25km points was damaged but was repaired. The team did not hold anyone responsible for the damage as the investigation is solely a technical one.

The final report will be submitted to the works and human settlement ministry soon.

However, the investigation team recommended that the damaged part could be reconstructed with different specifications to suit the geography.

Meanwhile, Taujay Chedup added that a second investigation will have to be carried out in the summer as the results can vary between the seasons.

Funded by the Asian Development Bank, the construction of the highway was completed in May 2015 from the Nganglam side and in October from the Panbang side.

Yangchen C Rinzin |  Samdrupjongkhar