Ok I try to make some comment to this topic. Actually track design can be quite interesting. I Ciro I would like to see how your ideal track design looks like. I think you are the only one who seriously thinks about the track layout from an analytical point of view. Well of course its part of your job.
One thing makes me wonder. You say a lot about snail, spiral curves ect. obviously you are very deep into the stuff because of your road design job. Actually I must admit I didn’t really understand what you meant with transition of sideslope, snail and spiral. However maybe you are a bit to deep into the stuff. I mean on a racetrack there can be a 90 sharp edged corner baaam. No transition at all. We have them in Singapur which is a quite sharp edged track but not bad because of this. Actually a sharp edged corner can be nice especially when they are consecutive. In the end the driver will make even between the sharpest edges some smooth transitions.
One more point.
I have heard Tilke follows the design rule of long straights followed by hard braking and slow corners to help overtaking or bring interesting races or whatever. When I look at the Tilke tracks I see this feature. Like in Shanghai with the looong straight and the following very slow corner. It is also in the new Hockenheim layout, in Yas Marina circuit, in Malaysia we have it even two times.
I think this idea is generally wrong because those long straights are really boring. There is absolutely noting happening when you drive along those much to long straights. You just wait for next braking and wait and wait then you get action for short time and wait again while you are on next straight.
As comparison Spa also has long straights but they are never 100% straight. They are interrupted by very high speed curves which are a challenge to drive trough. Then there are curves which are not super tight but more like medium speed ones. I think current tracks are to much “stop and go”.
Also for slow curves it should be paid more attention to have transitions between curves followed to each other. Currently most curves are separated from the next one by a straight which allows the driver to ideally place the car for it without taking any compromises. I think there should be sections where curves follow each other in very short distances so that the drivers have to compromise the lines for them. It should not be possible to place the car ideally for both ones. The very old double chicane at Monza was a bit like this. You could ideally go trough the first one but then you are in a bad position for the next one. You have to already think of the second chicane when you go trough the first one.
Current tracks are a bit like this:
right straight straight straight straight straight straight straight straight straight straight braaaaaking right straight straight……
I would like them to be more like this:
Left straight right left straight straight braking left-right-chicane straight straight double right straight uphill very fast right straight braking ….
I don’t understand much about music but I think we can compare driving on a track a bit with a song. The first one above would be very boring because its always the same. Nobody would like it. The second one can have something like a rhythm. It changes, its not just boom, boom, boom. If a track designer wants to be a real artist, like some say Tilke would be, then he takes things like this into account. There must be a natural flow when driving round a circuit. Left right left right… You start to feel and stop thinking. Also it must be possible to have alternative lines trough the combination of corners. The driver with the best feeling will get the shortest time, like a dancer. On most current tracks you wont get this because the straights hack the sections into parts. Monaco is a bit different in this context. It is a very nice flowing track also some parts of Hungary. It’s not that I don’t like straights. I also like Monza and the old Hocken layout very much but those tracks where special because the focus is on pure top speed. They had their own character which is easy to discover. This like the flow and the character of a track might be more important than specific attributes of curves circular, spiral or sharp edged transition.