Well, about Grab Taxi, the way these apps push their market share is by offering taxi's additional incentive (i.e. drive so many people in the first month, get additional bonus at the end of the month).
So drivers will be more willing to drive you into congested areas then they would without the app.
However, my guess is that they haven't worked out the cost-benefit yet.
So if he drove you into rush hour traffic, congested area he'd want more.
I use grab taxi when I don't want to wait at taxi queue.
