The Japanese government will begin the final stage of improvements to National Road 1 this spring if the tender process for its $2 million scheme passes without a hitch, according to officials.

Construction of the last 4.5-kilometre stretch of the road will begin in April if all goes to plan, according to Daisuke Fukuzawa of the Japan International Cooperation Agency.

“We designed four-lane roads with bike lanes, parking lanes for the most crowded areas, and sidewalks. The construction will commence in April this year if the tender is finished successfully. This is the final project for upgrading” National Road 1, he said.

The unsurfaced road has been a nightmare for local residents, who have been forced to put up with clouds of dust billowing into their homes while construction has stalled.

The completion of the long-awaited project will no doubt come as a relief to many of the communities living along National Road 1, which connects Phnom Penh to the town of Bavet on the border with Vietnam in Svay Rieng province.

The road sustained heavy damage during the civil war in the 1970s; repairs began in 1981.

A statement released by the Ministry of Public Works and Transport on Tuesday said the final stage of construction had been due to start earlier but was delayed because of a change in the road’s specifications.

Instead of a 7- to 9-centimetre surface, the road will now be 20 centimetres thick to limit wear and tear from the thousands of vehicles that use it every day.

“The added thickness is based on technical studies by the Ministry of Transport related to the quality of the road,” City Hall spokesman Long Dimanche said.

The $221 million National Road 1 project is part of Cambodia’s plans for ASEAN integration this year, when it is expected to become a major route for travel to Vietnam, and even as far afield as Malaysia and Singapore.

Japan’s investment in Cambodia’s roads also includes the Neak Loeung Bridge project, which is costing Japan $95 million.