Is it ok to drive with the bed mat and no tailgate?

I have a heavy duty bed mat by Dee Zee, I think. The air dryer in the car wash blows mine so bad I have to get back there and re-arrange it so it goes in/out with the TC. Why take a chance with it flying out and possible hurting someone or causing property damage? Roll it up, tie a rope around it and store it in the front of the bed. :)