A long long long time ago Armstrong Powerhouse release a product which removed the extra brightness effect on all semaphore signals which gave it a much closer experience to IRL. Would really like it if there was an option to basically do the same thing now.
They're not semaphore signals. The weather appears to be poor, are you sure there's not a slight fog of some sort? Have you noticed this in clear weather?
I have noticed this over flaring effect in particular on Rivet routes. Like adaptive eye and the nasty over exposure as you leave tunnels, it should be user configurable or able to be switched off altogether. I'm sure other games have options to control lens flare.
It's not weather related, they are like that regardless. It's a case of over flaring effect like OldVern mentioned. Armstrong Powerhouse Fixed the issue a very long time ago but only for limited routes for the DGT's TS. This is probably what TSW's titles should of aimed for in regards to Signals in my opinion. Eye prespective likes it as well. https://www.armstrongpowerhouse.com/signal_enhancement_pack