On the brink of a flat tire?

Sounds like you could drive at speeds under 45 MPH to your car dealer. Bring your cell phone. You really can't tell how much air pressure is in the tire just by looking at it unless it's almost totally flat. If you had a tire pressure gauge and there was less than 10 psi in the tire, then I myself would first pump up the tire with air before driving the car. You can buy or borrow a portable air compressor so that you can pump up the tire at home before you leave for the repair shop.