Submitted by the map’s creator, who says:

This is a route map of the GWR network. It’s my first time creating a transit map with Illustrator, so I’m open to any feedback!

Transit Maps says:

This is a pretty good first effort! In a way, this is a throwback to old railway maps, in that it shows where the trains travel, but not how they do so – individual routes aren’t indicated, so it’s impossible to tell from this map alone whether you can travel directly from one location to another. Still, that’s what the Internet is for, right?

I will say that the map gets noticeably more crowded the further west it goes, almost like Xsanda realised he was running out of space and had to cram things in. Notice how most station names are set horizontally near London, but have to be set at a 45-degree angle down in Devon and Cornwall. 

Some of the route lines could be simplified as well: the branch from Exeter to Barnstaple could be a straight line heading northwest, while the reversals of the line at Coombe Junction Halt and Bere Alston – while technically accurate – are unnecessary detail in a diagrammatic map like this. With a little work, the line between Newbury and Castle Cary could become a straight line as well.

I also think the enormous labels for major stations are overkill: I’d set them just slightly larger, or even just in a bolder version of the font to draw just enough attention to them. I think that this would help with the balance of the map as well.

In short: simplify, simplify some more and aim for a more even spacing of stations throughout the entire diagram. It’s tedious tweaking at this stage, but it’ll be worth it, I think.