There are a couple places where I regularly board a shuttle vehicle that takes me to and from an off-airport parking lot or offsite rental car facility. Two come to mind as frightening experiences.

1. Cleveland rental car center: These shuttle buses are lacking in suspension components. From the nonexistent shock absorbers to the uncushioned "foam" seats, it feels like there is nothing between the rider and the potholes that make up Cleveland area roads and highways. Each small indentation is met with a resounding boom as the shuttle bottoms out and a small trail of lug nuts and undercarriage bolts is strewn along the path.

2. PreFlight parking Atlanta: The vehicles are fine, but the drivers are card-carrying maniacs, NASCAR wannabes and sqeaky voiced teenage drag racers. No, the shuttles don't go from 0 to 60 in 4.7 seconds. But with a couple of green lights, the driver can usually build up a sufficient head of steam to take the first curved overpass on Camp Creek Parkway on the two left tires alone with nothing protecting you from the road below but the oft-replaced guard rail.

Any other nominations?