Asking can get you a lot of cooperation. But don't get mad if someone won't let you by. Following someone who is better at moving up, like you did, is a good way to move up yourself, and to learn how to do it better.
I often find that it's easier to go up the right side of the road than to hug the centerline. More people hang out on the centerline.
Watch the race. There are times when things get more strung out and you can use those to move up.