If I were put in charge of TAR, here are some changes that I would pitch.
Side Trip. Leg 1 would introduce the concept of a Side Trip. An optional additional task during a leg that frontrunners can go for that will bestow benefits for the first team that completes it. (Or more than one if you want to structure it that way.) Winning the Side Trip in Leg 1 would give a team the Express Pass. Other advantages could be given out, such as extra cash within the race, or a prize after the race, or the ability to Yield or U-Turn. I would install Side Trips in about three or four of the legs. Completing a side trip does not guarantee that you won't be eliminated if you come in last.
Detour limits. Some tasks have limited number of available slots for Detours. Say for example there's 10 teams left. There are only five tickets for each task. This will be done with tasks of relatively equal difficulty but different strengths.
No Yields or U-Turns as we know it. I think it adds very little to the game. Or, if TPTB is so in love with the concept that it MUST have them, have it be earned by winning a side trip. I would keep the name of the U-Turn but would have it be automatic that the last two teams in a leg to finish the final task would have to complete both sides of the Detour, creating a natural merit based duel for last.
The Fast Forward will be no more, but will be reborn as the Short Cut. It would still be a task that lets you skip the Detour and Roadblock. Three times a Short Cut will be available. Early in a race, a Short Cut will happen which will let the first three teams skip the leg. In the middle of a race, there will be a Short Cut for two teams. Late in the race, there will be a Short Cut for one team. A team can only do one Short Cut per season.
I'm trying to think of a good innovation for the final leg, but I'm not coming up with one except that there should be a good memory task.