I get deliveries from Amazon and other internet vendors from, among others, two regular drivers, one from DPD who used to drive for CityLink for over 10 years, and the other from Hermes who has been with them for 3 years. I used to work for a shop near me that sells worldwide shipping services, so knew them from there.
They both say it's down to being organised. They do not have problems getting their deliveries out, and this is in a densely settled part of the city.
They do say that some first-timers struggle with a poor knowledge of the area (that takes time) and organising their routes, etc. It's not a doddle job, and you need to know the area you are working and using the satnav does not always give the right route-planning.
About map reading: I was lost once trying to find a place in Cardiff, I parked up and took my printed out google map into a shop and asked for directions. The man (in his 30s) just stared at the paper then said he didn't know how to read a map!!!
Another unpleasant experience... I ordered a mattress from some offshoot of Littlewoods. The company's own driver rang me and said he was three streets away and could not get his van down our street (too narrow). I asked what he was driving? It was one of those small box vans.
Bloody heck, I said we get coaches for the church come down our street! He refused flat out and said it would have to be rescheduled with a transit van. Order cancelled!
Royal Mail posties were not happy when they were required to walk their routes at a certain pace. This was in 2008. I do not know the outcome of their protest.
www.telegraph.co.uk/news/newstopics/howaboutthat/3708085/Postal-workers-bullied-into-walking-faster-by-Royal-Mail-claims-union.html
Our postie said there were not proper pavements in many sections of the city, and you then have to find something to put the cart's cable lock around when it's out of your vision and these things slow you down. I could not see how they could walk that fast myself. She went off our route not long after, and our current posties seem to change all the time.