Thanks everyone for sharing your experiences!

Min - the reason a little ride on or push bike wont work is that I have to catch buses & trains, and I really dont want to have to lug something big on there (especially during peak time!) hence the reason why I cant (dont want to) take a pram either.

We have asked MIL to order us one anyway now with her CC, so it should arrive this week, and I will do a trial run with Aidyn to the city when it gets here - as uni starts again next week!
I *think* he will be ok, because he will be a in a strange/exciting environment I dont think he will be likely to tantrum and protest, and he'll probably want to stay by my side... but I want to be safe JIC he does try to run away.