Like in the PC version, it's most likely just an achievement with no in-game incentive. It's just a little thing to get you out and exploring the world a little bit. I know someone on Steam made a guide to get all the collectibles for the GWE route. A quick Google search will lead you to it.
I have one collectible, just accidentally walked into it. It is not an achievement so I didn't worry about it. Maybe with the new dlc in the future new achievements, little more challenging?
I just watched the video on youtube that was mentioned by platchap, way more items at paddington then i first thought
I have found a lot of collectibles now. 14/25 Route Maps; 19/25 Dispatch Batons; 21/25 Safety Signs. The big stations have more indeed.