Or maybe red warning lights instead of yellow warning lights. Maybe they have changed it. But yellow lights to me doesn't suggest "you absolutely need to stop".
edit: okay. Now they have a sign. With white lettering. In a location where we know from years of experience drivers aren't looking. This makes no sense to me. Everything about this is bad design.
There are at least five signs at eye level on the road leading up to the bridge, four of which are the standard yellow warning signs: https://imgur.com/a/owITLZC
In addition, the illuminated "OVERHEIGHT MUST TURN" sign flashes to attract attention.
I get what you're trying to say, but this bridge is better-marked than the vast majority of road hazards one might encounter. There's a certain point beyond which it doesn't make sense to keep spending time and money protecting people from themselves.
The bridge just shrugs the hits off it is very tough. So the damage and the problems are really for the trucks not observant enough to see half a dozen warning signs and lights.
They are the ones who end up paying, not the railroad that owns the bridge.
edit: okay. Now they have a sign. With white lettering. In a location where we know from years of experience drivers aren't looking. This makes no sense to me. Everything about this is bad design.