GPS making your trips longer?

I am not too sure on how GPS operate and its technical features but i was just sitting here thinking, if it finds the shortest path to follow to travel from X to Y and GPS become cheaper and more popular and everyone has one, wouldn't everyone all go to the shortest path which would make the shortest physical path and longest in time to travel as it now has concentrated traffic and maybe even traffic jams?

Or maybe GPS now or maybe future designs will be active and can detect other cars on the road and know which roads are being heavily used or maybe even avoid traffic jams due to traffic accidents... but then once again if everyone has a GPS and everyone goes to the alternate path to avoid the traffic jam due to the traffic accident wouldn't that again bring us back to square one (paragraph above)?

Feel free to comment with your knowledge or thought