Interpretation of "по одному"

Question

What is the function of по одному in the following sentence?

Брежнев ехал на машине по одному из московских проспектов

I did some research and apparently it means one at a time, that doesn't really make sense here, however.

Isn't it better to just use something like по улице in this case?

Answer 1

You are mixing two completely different cases here:

1. брал предметы по одному - took the items one at a time. Here, "по одному" is an adverb;
2. ехал по одному из проспектов - drove along one of the roads. In this case, "один из проспектов" is the object.