Do you really mean ALL.
I use the A20 to Mottingham most days, and on the homeword journey its uphill, so i don;t get a lot of speed up, there are drains, bits of trees, dead animals and cats eyes in the side of the road I use. This road is also beloved of boy racers who get up to a whopping 60 or 70 mph, before slamming the anchors on at the speed camera, and then accelerating again. The combination of low speed, obstacles on the road, and complete wankers in vehicles makes this very dangerous for me. I've only been hit once on this road, but that was enough for me to make an important decision.
In the other direction where I get a good speed up I have no problem getting a good road position and keeping my space on the road. Most people pull into the other lane to overtake me; and its too early for boyracers in the morning; and traffic is usually much slower, I can end up being as fast or faster than the flow of traffic.
Considering that there is a nice wide pavement on either side of this road, never used as far as I can tell, by pedestrians, which the councils concerned refuse to reclassify to shared use cycle path (don;t know why) - then it seems obvious to me that I should cycle on the pavement on this route.
I hurt no-one. I stay alive.