The only real TL effect on city maps would really be grav vehicles reducing road width back to walking only (in crowded places)
It would be interesting, because while you would have walkways, you also need landing, loading, and parking areas for the vehicles. What would certainly be lacking is interconnecting highways between population centers. Depending on the world, I don't think aircraft would be flying "below rooftop" level for the most part, they'd simply climb over all of it. There may well still be traffic lanes to get in and out of (vs just flying willy nilly across town), but, unless you have very high sky scrapers, I think it would be prudent to have everything fly high.
It would also be an interesting phenomenon about density. Is there a demand for high density places? Since travel may well be "fast and cheap", the inner cities may well be lower density that they are today. The "rush hour" is either waiting for a landing zone.
Do you think the traffic lanes would be much like current highways? Perhaps organically broken up into not just horizontal lanes, but vertical ones as well? Consider your typical 4 lane freeway. Stack 4 of them and you've quadrupled the density and traffic flow. Which is pretty good, and "free".
I wonder if at busy buildings there would be "hover jams" as the vehicles queue up for a landing spot.
For parking, if the vehicle were autonomous (likely), you could have large plains or specific parking structures away from the core where the vehicles can park, and then you just summon them in advance when you're ready to leave. "Please do not let your vehicle hover idle in the pattern for more than 15 minutes, thank you!"
Of course, with autonomous vehicles, you'd likely have much more ride sharing going on, which could reduce the parking demand, but personal vehicles still would need to be dealt with.