Never let your dog off its lead unless you are sure it won't run off. Not only can it get itself injured or killed, but it could also cause an accident or injury which could prove to be extremely expensive.
Also, ensure that your dog is securely restrained when travelling in any vehicle. A car/truck harness can be purchased for about $10.
-----Response from Vicki:
Thanks, Giovanni. We've seen a few dogs at truck stops being walked on a dog leash. It could be very difficult for a truck -- especially a fully loaded one -- to stop quickly if an unleashed dog ran out in front of it.
Drivers, how do you restrain your dog, both in and out of the truck? Please comment.
For more tips on pet care, please see Giovanni's site: http://www.my-pet-care-directory.com/