To carry on walking to another carriage

Not at all. You both said hi so you’ve ticked the polite box. Don’t even give it a second thought!

Not rude at all! A dear friend and I both worked for the same company years ago and got the same train - I got on first and she got on a few stops later. Occasionally she’d get on and sit with me if she saw me but by and large we wouldn’t see each other until we got into London and then we’d walk to work together. She admitted that she liked the train journey on her own to read and I was the same. No problem whatsoever.

I never sit with anyone on the way in to work. I used to have a direct colleague who lives near me and gets the same train, I told them to expect I’d say hi and walk on by. We’d get the train home together tho which was always nice.

one of my worst train journeys was on the way home from a (very draining) conference and a colleague plonked themselves down next to me and talked non stop. I was ruined by the time I got home.

No i would be relieved.

Absolutely not.

On work trips I've been known to deliberately book a later train back than a colleague, just so I can have a couple of hours to myself

I've done this too!

I'd find it odd if you just walked past with no actual acknowledgement. You said that you said "hi", but that could mean anything from "eye contact, smile and Hi" while still heading to your own seat to pretty much ignoring them, as you walked past with your head down. But certainly not rude for not sitting with them.

Nope. When I went to the office regularly I got the same train as a colleague. We'd chat while we waited for the train, then both get our books out once sat down.
I think this must be pretty normal as I had to travel for a work event, and then a few of us were getting the same train back. We all ended up separating in the station then standing far enough apart on the platform to end up in different carriages.

I'd be glad.

In fact I'd be gutted if you joined me as I also like my time to myself.

Ah okay yeah it would be different then.

People who ‘love to chat’ usually mean by that…gossip, or chat about inane shit like Love Island or whether Gemma has lost weight…

I didn't say the Op was weird...I said I'd think the situation was weird, but the latest op post says friend not that close so that's different!

Yes really hurt if it was a close friend.. I'd assume I'd done something wrong...

Not unreasonable.

I used to get on the same train as a colleague who I got on well with every morning for 3 years. Apart from a nod and a hello, we ignored each other.

We both discussed it and agreed that we don’t want to spend our morning commute chatting. We want quiet time and to read and agreed not to chat.

What do you mean, ‘whatever next’? The concept of people wanting a bit of peace and quiet now and again isn’t new. It’s a just an ordinary human instinct that applies to most people at some point. Very few people want to be chatting to acquaintances 24/7. Most people need a bit of time to themselves to have a break from company. That’s all.

I would have done the same - don’t feel bad about it.

If it was someone you were very friendly with but hadn't seen for a while then it would be a bit pointed and rude but, otherwise, many people prefer peace and quiet on their journey and would be relieved not to have to chat.

OP is not weird or rude.

When I am travelling, especially if I am on my own, I enjoy just doing my own thing and having some "me" time. I don't want to be regaled with someone else's inane witterings/drivel.

No. My two colleagues and I always say how we avoid people travelling home. It's our personal time.

Not interested in listening to irrelevant chat or gossip. It's boring.

Social battery?? Whatever next...i think im getting too old!

Do you lack theory of mind? You may love to chat, the other person may not be so keen. Or the other person may love to chat, but not first thing in the morning, or when they're trying to finish something for work, or when they normally spend their train journey peacefully reading their Kindle. None of this is 'weird', and none of it is anything at all to you with you, unless you feel your preferences should take precedence over theirs?

I'm glad I don't know you. I'd hate thinking I had to spend "quiet time" engaged in small talk with someone I know. I love the peace and quiet and being able to retreat into my own mind. It's the same on my canal walks which I do every day, I know lots of people who are also walking, but barely ever stop to chat etc - we're all doing "our own thing", some are walking fast for exercise and wouldn't want to be slowed down by a slow walker, some are walking their dogs so maybe have time to chat, but others are walking to/from work, or school etc and just want to get on with it. No one seems to think anything of it - we're all pretty good at "reading the signs" when we either don't want to stop or when we do. If someone is striding purposely with a pretty quick walk, it's pretty obvious they're not wanting to stop, but if someone else is stood watching, say, a Kingfisher, they're "game" for a quick stop and chat. Likewise dog walkers don't want "small talk" when their dog has done a massive smelly poo and they're trying to pick it up!!

When i used to drive to different towns in my job, some colleagues would also be going. My worst nightmare is if someone would suggest to share... I used to make up child responsibilities or doctor appointments as an excuse to avoid having to share. My space, my talking book etc. And im generally sociable. You did the right thing

So a proper friend of yours?? Have you seen them socially recently.
Honestly, if it was a good friend that I don’t see that often I’d be pretty hurt if all I got was a ‘hi’ and ‘bye’ without any other explanation or conversation.
I think walking straight past someone you ‘know well’ without engaging in conversation is a bit odd.