"I often meet her on the bridge."
Translation:Jag möter henne ofta på bron.
Arnauti posted something about the word orden in swedish: https://www.duolingo.com/comment/8970470 And according to that I believe that the right order should be "Jag möter henne ofta" But someone would have to verify if that rule always apply.
Sorry, specifically in this section: 1.1 Adverbials in main clauses
träffa på as a particle verb means 'run into', so it's like a chance meeting.
If you'd say Jag träffar henne ofta på bron, it would mean that the two of you meet there on purpose, but when you say Jag möter henne ofta på bron, it means either you meet her there by chance, or you go there to meet her.
I think there are more subtle differences between those two verbs but this is a start.