Autonomous trucking software developer TuSimple successfully traveled nearly 39 miles on an open public road in China, safely navigating normal traffic. The truck had no human occupant or outside help, the company said.

The driverless run covered designated public roads approved by the Shanghai government. They included the Yangshan Deep-water Port Logistics Park and the Donghai Bridge. TuSimple said last week it had been awarded a fully driverless test license by the Pudong New Area of Shanghai.

During the test, TuSimple China’s autonomous truck navigated complex urban roads and highways within the port area. That included traffic signals, on-ramps, off-ramps, lane changes, emergency lane vehicles, partial lane closures, fog and crosswinds.

A safety vehicle followed the autonomous truck but did not interfere with the operation. The company worked with government regulators and law enforcement.