I used to do 7am starts when I first started HGV driving and was happy with it…pretty much in line with the majority of friends/other workers etc, although that was assuming I’d get finished before the evening rush hour started
had a break from driving for a few years and now prefer either much earlier or much later start times so you’re guaranteed not hitting both sets of ‘rush hour’ traffic, if I could make myself get to bed early enough I’d prefer early morning 1-3am start but basically I can’t 
so early afternnon start times is now my preference