I was discussing about this on another forum, and I quote here a message of mine.
“I think I’ve realised what makes Interlagos’s main straight and Spa’s Kemmel straight so good overtaking places. Interlagos’s 3rd sector enables cars to drive close to the car ahead, as most corners are slow. But then, there’s faster Mergulho corner, which somewhat stretches the queue before Juncao. Abu Dhabi’s problem is that the chicane before T7 causes the car behind catch the car ahead, making the car behind unable to get a speed advantage for the following straight. At Interlagos’s Juncao the car behind can get speed advantage for the long straight, and besides, the downforce loss’s effect at Juncao is not too big.
I think Spa is somewhat similar. Before Eau Rouge, there are the slow corners of Bus Stop and La Source, enabling the car behind get close. Then, Eau Rouge is a corner where you can gain speed compared to the car ahead. But Abu Dhabi. I think the pit straight would offer best overtaking opportunities, but it’s just too short, and you can’t lenghten it, because of a canal. IIRC, Alonso was often closest to Petrov exactly at the pit straight, because Abu Dhabi’s S3 has somewhat similar features to Interlagos’s S3. The hotel complex’s 90-deg corners are slow enabling the car behind catch the car ahead. Then, there’s somewhat long straight followed by a medium speed penultimate corner. The last corner is a bit Juncao-like, enabling the car behind get speed advantage. The start of the lap is maybe the nicest section to drive, but it’s bad for overtaking. I’d say it’s the only part of the circuit where the car behind loses downforce, and replacing chicane-hairpin sequence by a long-radius corner, as has been proposed in this thread, wouldn’t help overtaking either, because of downforce loss. So, I think a Juncao-like 90-deg corner before the long straight might be the least bad corner before the long straight. But that wouldn’t be a good solution considering the grandstands at the hairpin. Also, the T8-T9 chicane could be a bit faster, making overtaking at the second straight maybe a bit easier. But, redesigning the circuit and relocating the grandstands might be the only way to make Yas Marina provide good racing. ”
Then, I thought that let’s change the direction of the track, so that S3 becomes S1.
The hotel complex would need some reprofiling to accomodate some runoffs at brakings. But the first significant change would be at the place of current T11-T14. I’d replace those corners with a 90-deg corner leading to a flat-out sweep, like at Interlagos’s Juncao. Then, the chicane between the long straights would have a sweeping exit. As the straight leading to hairpin would need some runoff at the hairpin, I have a tight turn already some 200 meters before the hairpin, and then have an ‘arena section’ at the place of hairpin. After the hairpin there would now be no need for the chicane, but the current T1-T3 might need some reprofiling because of different runoffs needed for different driving direction.