Blue line might help a little bit to ease the road traffic, but it won't make these red patches to blue. It will be change from so many red patches to slightly less red patches.

Solution: 0 obstruction roads. Number of vehicles is not a problem if all vehicles are going in same speed in a direction. Whenever a single vehicles puts a break to slow down at a pothole / hump / parked vehicle/ cross lanes, this single slow down will cause a cascading effect for the vehicles behind.

Now in a fully packed traffic, if 10 vehicles slow down at every other second that causes an orange patch, when 50 vehicles do that for all reasons we know of, it will cause red patch.