This is something they all go through and some grow out of. I used to scout the field and pop Simba's lead back on if there were people/dogs around. But the problem is you cannot practice your recall in these exciting situations if you do not go through them regularly. Practice makes perfect so try it everyday.
Simba slowly realised that humans were not very exciting so she wouldn't bother with them (around 7-8 months old). Then I would let her off but show her all the delicious treats I had and if she stayed near me she got some as well as I would run through the woods with her, the kids would be climbing trees, she would be trying to join them. She then would not run off over the field even if another dog was there( around 10-11 months old).
I can remember the embarassing situations when she tried to put her head in a womans shopping bag etc. She still does every now and then run over to another dog but she does come back swiftly when called. They do improve but it is a gradual process. Good luck.