One year on, the Chinese-invested Phnom Penh-Sihanoukville Expressway has significantly boosted tourism and economic growth in Cambodia, senior officials said on Tuesday.

Cambodian Deputy Prime Minister Sun Chanthol said the 187-km expressway has been playing a crucial role in improving travel efficiency, reducing traffic jams and shortening travel time between the capital city and the international deep-water seaport city of Sihanoukville.

"The expressway has importantly contributed to boosting Cambodia's economic growth and tourism development," he said in a speech during the celebration of the first anniversary of the expressway.

The freeway was one of many major achievements in Cambodia under the framework of China's Belt and Road Initiative (BRI) cooperation, he said, adding that the Siem Reap Angkor International Airport, which started commercial operations last month, was also a testament to the fruitful cooperation between the two countries under the BRI.

"The BRI has helped Cambodia and other participating countries to develop their respective countries," he said.

Chanthol said the BRI has provided mutual benefits and win-win cooperation for all.

"The BRI has greatly supported infrastructure development and economic growth in the kingdom," he said.

Invested by the China Road and Bridge Corporation (CRBC), the Phnom Penh-Sihanoukville Expressway is the first-ever freeway in Cambodia and is a major project under the BRI cooperation between Cambodia and China.

Cambodian Minister of Public Works and Transport Peng Ponea said the expressway has importantly facilitated travel and goods transport, adding that it is time-saving, convenient and safe for passengers.

"This expressway is a key strategic route, as it connects the first economic powerhouse of Phnom Penh with the second economic powerhouse of Sihanoukville," he said at the event. "It has been providing great benefits to our socioeconomic and tourism development."

According to the expressway operation company, some 5.19 million vehicles had traveled on the expressway during its first year of operations.

With two lanes for traffic in each direction plus an emergency lane on each side, vehicles will be able to reach their destinations within two hours through the expressway instead of five hours on National Road 4.

Seng Chien, a 65-year-old user of the Phnom Penh-Sihanoukville Expressway, said traveling on the expressway was very convenient and time-saving, and he experienced no traffic jams.

"I saw beautiful scenery on both sides of the route that runs through several provinces and cities," he told Xinhua.

"This expressway's quality is good, and I would like to urge people to travel on this expressway if they go to Sihanoukville. Traveling on the expressway is much better than traveling on a common road."

Touch Sereyvuth, another 42-year-old user of the expressway, said passengers can also enjoy beautifully green scenery along the route.

"I recommend people to use this expressway because there is no traffic congestion, so they can save some money on the expenses of petrol and vehicles' maintenance," he said.