How to carry a convertible travel backpack on the train/tube

Carry it as a suitcase. Otherwise you unwittingly bash other passengers. This is also true when boarding or exiting a plane.

I've been hit by people wearing backpacks on public transport way too many times.

It does if you like what is inside your bag. Carry it as a suitcase or over one shoulder and put it by your feet if standing or between your knees if sitting. If it is on your back it is possible for a clever person to examine the contents of your bag without your knowledge.

Riding BART (SF area transit) this afternoon the train operator reminded passengers that backpacks should NOT be worn on backs but placed by feet to ensure that there would be room for other passengers. And these were largely daypack-size packs -- but still big enough to knock sitting passengers in the head.

Few professional people use briefcases these days - we use backpacks, but they are smaller than the size you are probably talking about. Wear it to get to platform level then take it off before you board the train and place it at your feet onboard. When wearing it, keep still and don’t continually look round and bang people with it.

In rush hour, there’s nothing worse than people walking two abreast in the corridors and on the escalators slower than the locals, dragging a suitcase on wheels, so wear it.

If you want to carry it without bumping into people and you want to see if anybody tries to pilfer it, wear it on the front. That goes for trains, buses, and planes.

If the train/tube is even moderately busy, carry it. It’s so annoying when ppl don’t, and also have no concept of the ppl around them and twist and turn while forcing their huge backpack in others faces... it happens too often. If the train/tube is empty... wear it, no one will care.

It’s not about wearing it or not, it’s about consideration for others... which the British are generally quite hot on.