Autonomous vehicles promise to improve safety and transform how people move place to place. They’ll also free people from the burden of driving and a new study suggests they’ll use this time for some hanky panky.

As noticed by NBC News, a paper published in the Annals of Tourism Research suggests autonomous taxis could become mobile brothels. As the paper speculates, so called ‘hotels-by-the-hour’ could be replaced by autonomous vehicles which just drive prostitutes and johns around while they do their thing.

That’s an unpleasant thought, but the paper suggests companies will likely install cameras in their vehicles to deter people from doing illicit behavior (drugs, sex, etc) in them. However, cameras are unlikely to be installed in autonomous vehicles owned by private citizens. If these vehicles are then put into commercial service, such as through a ride-sharing app, the study says it’s “just a small leap to imagine Amsterdam’s Red Light District on the move.”

Of course, sex in cars isn’t unheard of and the paper cites a previous study that found 60 percent of Americans have already had car sex. It’s also worth noting that prostitutes and johns won’t be the only people getting it on as couples will have plenty of time to kill on longer road trips.

NBC spoke to the leader of the study and Scott Cohen said he doesn’t expect sex in autonomous vehicles will be an issue anytime soon. He estimates it won’t become a problem until the 2040’s.

The other claims in the paper aren’t too surprising as researchers suggest autonomous vehicles will negatively impact hotels. Since people no longer have to drive, they can simply sleep in their vehicle while still traveling to their destination.