A man in the southwestern Chinese city of Chongqing didn’t expect that his Weibo post of an unusual ridesharing experience would catch the attention of traffic police after it went viral overnight.

Using a local ridesharing site, the man found a driver who agreed to take him from his home in Wushan County to Chongqing on Monday, June 26.

“I was wondering if a recreational vehicle might come to pick me up because the driver told me the space was big enough for me to sleep,” the man wrote on his Weibo account on Tuesday. When the vehicle arrived, he was kind of freaked out: it was a freight truck.

True to the driver’s description, the man could lie behind the driver’s seat and have a rest, but he didn’t dare close his eyes for long during the six-hour trip. “The truck was traveling at full speed. The driver tried to help me relax by saying he was very experienced,” the man recalled.

“The trip turned out to be safe, but I’ll ask about vehicle type before using any ridesharing service again. It could be an oil tanker for all I know,” the man joked at the end of his post.

The man’s adventure soon sparked the interest of China’s internet users, as well as two separate probes from traffic police and the owner of the truck.

In a response to a Chongqing-based media outlet, the man, who only identified himself as an insurance salesman, explained that the truck was his only option, because it was so late and he had a next-day business appointment in Chongqing he couldn’t miss.

The salesman said he had not expected his post would cause trouble for the driver and he removed the original post afterward. In his latest post, sent on the afternoon of Wednesday, he clarified that the driver wasn’t speeding and he shared the story because it was just an odd but funny experience.

The truck company said it is against both the law and company policy for truck drivers to offer ridesharing services due to safety concerns. The police said they are still investigating whether the driver was speeding or if he was driving while fatigued.