The main issue with the expressway are its entry and exit points. Those those who have to enter or exit it have to wait at traffic lights,,especially the al waab and salwa road intersections. All in intersections should be free-ways so that cars can freely enter and exit the expressway without having to then wait at traffic lights. For example, when you are traveling at a speed, whether its 80 or 100, and you have to exit to join salwa road and all of a sudden have to stop at a light and give way to other traffic before joining salwa road. What happens is that traffic builds up and the queues reach up to the expressway. There should be bridges connecting all major roads crossing the expressway, so that cars exit the expressway and without stopping join the other road. I think 80 to 100 makes no difference at busy times, as average speed is around 40 or 50. Even if you find a gap and speed up, you will still have to slow down as the whole traffic is moving slower at peak times. At busy times, I bet if you do an average speed check while driving through the D-Ring road, you may at times drive at 100 or above, but you will really find your average to be less than 80 for your time on the D-Ring expressway. Its about time the highway/ traffic department starts seriously building bridges and create more freeways to ease the congestion.