The headlights cast way to much light in the day. In real life you can’t see the light being cast onto the ground and objects during the day. This is for all trains in TSW.
And they're casing way too little light at night. North American locos have insanely bright headlights - they light up at least a quarter mile in front of the locomotive. Unlike european trains, American trains' headlights are there primarily for the driver to see what they're approaching. Secondary is a warning for others.
I have no idea why its like that in both TS1 and TSW. In real life a light that is bright at night does nothing to ambient lighting when sunlight in involved, but in both TSs, a light thats bright at night bleaches everything out during the days too. I would have expected UE4 to handle the fact that sunlight cancels out any headlight we can make...but no...Looks like they would have to code lights to specifically to reduce brightness in sunlight. Heck, MSTS/Open Rails has this issue and there is an option inside the lights on a .eng file that makes the lights dimmer at day, then get brighter as it transitions to night. Work well, even though its mundane. I know some TS1 3rd parties are finding ways to do exactly that.