PS it is totally a feminist thing that it is hard to navigate space, steps, buses etc with more than one toddler. tbh it is not necessarily the spaces that have to change, as much as our expectations and general willingness to help and accommodate (arguably)
I have been on the verge of completely bottling out of a full bus (in South London) and then instead, experienced what felt like physical space rearranging itself around me, due to people's understanding, willingness to help, and knowing what to do. Things just happened for me and around me and I found myself (a few times) in a seat with a baby on my lap, a toddler on the seat next to me, all the heavy bags in the luggage space and the buggy folded up alongside them. This happened on a bus that appeared to have absolutely zero space before all the kind and capable women on it took over.
Similarly I have been in objectively much easier situations and felt like crying because people were just being so shitty about the fact that I had two children, and bags, and only two arms, and there were a few obstacles, and so on, and people were just being utter shits about it. "What do YOU want me to do?" (I did not shout) "grow more arms? Give away my baby? WHAT?!"
(this is why I hate certain threads on mumsnet where I feel like people are ganging up on the exhausted woman instead of helping her like the blessed women on the bus)