CHONGQING -- Restaurants at expressway rest stops in southwest China's Chongqing Municipality are different from others across China -- there are no humans waiting on tables.

The first robot servers went to work at Wulong and Dalu expressway rest stops in Chongqing in the middle of the month, the local traffic committee announced Saturday.

Customers order food via a terminal and pay their bill online. Robots bring the food to their tables.

Zheng Yi, operations manager with the Wulong rest stop, said robotic staff slashed operating cost.

"If their performance is good, the robots will find work in more restaurants along the city's expressways," Zheng said.

The trend of smart tech in service has grown in recent years. In addition to attracting curious customers, they have proven to be efficient and helped tackle rising labor costs.

Service robots are already used in package delivery, elderly care and hotel reception.

During the Spring Festival travel rush, some 20 robot policemen are even patrolling a railway station in Shenzhen.