My TKR was almost a year ago. Three and a half months after my surgery, we took a four-hour road trip to North Carolina. The trip went ok, but my knee was stiff and achy afterwards. I did not drive. I kept my foot elevated in the car by putting an old bed pillow in the floor under my feet, and we stopped every hour or so to allow me to around walk for a couple of minutes. I also wore compression socks. I expected my knee would complain, but I wanted to make the trip so badly I didn't care. After the trip my knee was swollen so I had to use a lot of ice packs. But if faced with the same situation in the future I would do it again. You get so tired of being stranded at home! Best of luck on your trip!