"We run over to the bridge and we run back."
Translation:Elfutunk a hídhoz és visszafutunk.
Yes, that is also good. The difference between "oda" and "el" is so small in this case that it is not worth going into. But anyway, "oda" sounds more purposeful, wanting to do something with the target, while "el" wants little to do with the target, only uses it as a distance marker. Never mind.
Well, "el-" can be relative to both a source and a target. Away from here or away to somewhere. "Oda" is definitely to a target. Maybe that is why it sounds more purposeful.
If you want to walk up to a girl or boy and introduce yourself, you use "odamegyek". Definitely with a goal in mind.
If you want to run as far as that bridge and then turn back, you have not much interest in doing anything with the bridge except use it as your reference point:
"Elmegyek addig a hídig és visszafordulok."
"El-" is used mostly here to indicate the target of an intended completed action. The sentence strongly suggests that the stated goal will be accomplished.
Do not take these as rules set in stone, these are just nuances, feelings.
Btw, you may not have seen the "-ig" suffix yet. It stands for "as far as" in the "until" sense, or for "until" itself. It can be used both for distances and time, and other, figurative meanings.
The sentence above would actually sound better with "hídig" to my ear.