If something is stolen in a highway service area, is the service area responsible?

The service area is a public place. If there are warning signs in the service area warning passengers to pay attention to theft, then their obligations have been fulfilled, and the service area has no obligation to help you take care of your items. This can be used to investigate the murderer based on the surveillance video at the toll station or service area. The obligation belongs to the police, not the service area. Also, expressways charge road maintenance fees, not guardianship fees to help you look after your belongings.