An expressway between Phnom Penh and Sihanoukville is slated to begin construction next year in a bid to relieve traffic on the two-lane National Road 4.

The project was announced at a ceremony in Phnom Penh on Tuesday and will be constructed by Chinese firm Henan Provincial Communications Planning, Survey, and Design Institute (HPCPSDI).

Construction on the road is set to begin next year and finish in 2020, state news outlet AKP reported.

Ministry of Public Works and Transport spokesman Peng Sovicheanou said the project was aimed at relieving congestion in order to boost the economy.

“Have you ever travelled on Road Number 4? It’s very congested,” he said.

“Cambodia is following other countries like Korea, which have had huge economic booms.”

Sovicheanou added that the expanded road would be entirely paid for by the Chinese company, although the final cost – which AKP said would total $1.6 billion – was still undecided.

HPCPSDI signed a contract at the same ceremony last week to draw up a road network master plan for Cambodia.