Originally Posted by
tonywestsider
I also suspect that flaps down during runway roll after landing increases drag and supplements using spoilers to slow down the plane prior to moving on to a taxiway.
This is also true, but as previous posters have mentioned, the primary reason is safety. There's simply too much happening in the cockpit during that phase of flight to worry about getting the flaps up. It's important to note that on many commercial jets, the flap handle is located right next to the landing gear handle. There have been instances where in the hustle of it all, the wrong handle was pulled. (Most modern airliners now have a safety mechanism that prevents gear retraction with the full weight of the aircraft resting on them.)