I have done a variety of rides through big cities in the past four decades San Bernardino, California through Anaheim to Newport Beach; (Ft. Knox, Kentucky to downtown Atlanta; Ft. Knox through Detroit to Niagara on the Lake, Ontario; through Portland, Oregon, and Minneapolis, then Ottawa to Portland, Maine; Seattle through Indianapolis, then Columbus, Ohio on to Rehoboth Beach, Delaware. I find that being on a named/numbered highway in the city (whether US or state highway), there are adequate signs showing where to turn. While not opposed to GPS, or other systems, I have never needed them to get where I was going following adequate map study/planning.