I am 11 weeks post op TKR and just did a 12 hour drive in one day. My husband and I stopped every hour and a half to walk and stretch. I drove for 2 hours of the trip. When I was a passenger I did a lot of ankle pumps. When we got home my Knee, leg and ankle were swollen but no pain. I iced and elevated and it is back to normal this morning. The previous week we did a two day trip of 6 hours each day. We also stopped frequently. I had no pain or swelling with the shorter amount of time. So we decided to drive straight home on the way back which was our 12 hour trip. In retrospect it probably would have been better to do the return trip in 2 days instead of one. I'm continuing to experiment with how much activity I can do at this point. Hope you have a wonderful road trip.