After starting queue, we should be able to mark off what roles we would like to play. For example, if you want to play top lane, check off top lane and leave the others unchecked. If you can play any role, check off everything. There can also be an option to set defaults so that you do not have to check off the same thing every game. There are far TOO MANY times when people complain over who plays what roles, and we get two people locking in that role. And ofcourse, this leads to dodges, or a bad-experience game.
You may say, you shouldn't be playing ranked if you can't play any role? What if you're a much better top laner/jungler than you are bot lane/mid? And sometimes you are just in the mood to play a certain role. So at least try implementing this into normal games.
I don't see how this can cause any problems. It will only lead to better cooperation within teams, and it will make the elo system more accurate. You won't have as many losses due to bad team comps, so your skill level is taken more into account.
Please thumbs up if you agree, and if you don't, I would be glad if you could post your concerns.