Temporary, post 9/11 restriction imposed by the Port Authority of New York and New Jersey requiring all cars entering the Holland and Lincoln Tunnels during rush hour to have more than one occupant. This caused NYC-bound drivers to pull up to complete strangers at NJ bus stops and ask if they wanted a ride into the city. Sharing of tolls was optional.
Bus stop standee 1: "Did that dude in the Mercedes just ask you if you wanted a ride into the city?"
Bus stop standee 2: "Yeah. Must be carpool tunnel syndrome. I might have accepted, if he didn't have a boner."