Peculiar preemption

In the "random local weirdness" category, there's this blurry cell phone picture of a construction sign erected this morning on the west side of League City on SB Bay Area Blvd. at FM 518.  This one had my husband and I so curious that I just had to research it, and if I go to the trouble of researching it, might as well blog. 

Sorry about the poor pic quality, but it reads "No Railroad Preemption".  Ever wonder what the heck that phrase actually means??  Apparently a lot of people have wondered - because look at the autofill suggestions on Google:

I only got first four letters of "railroad" typed before it knew exactly what I wanted. 

A railroad preemption occurs when people driving trains are able to over-ride a road intersection's traffic light signal pattern in order to freeze the progression of vehicles as they are passing through.  The train itself preempts the normal flow of traffic, in other words.   This is something they do ostensibly to increase safety. 

Here's the weird part, though:  there's no railroad within three miles of that particular intersection.

Huh?!?
(Screengrab from Googlemaps)

This is my best guess as to why the warning sign was posted there: Because the construction crew couldn't put their hands on the correct sign, so they used the closest available approximation. 

There's a fire station near the intersection, and fire trucks are another type of vehicle that sometimes has the ability to preempt the normal flow of traffic so that they can get through the area quickly.  It should have read something like "No Emergency Vehicle Preemption" but maybe their supplier was out of those signs.

That's my best guess, anyway.  But I could be wrong, so if anyone happens to see a train flying down west FM 518, please drop me a line because I'd love to hear about it.