I was driving to work this morning from the gym, and a sign on a lamp post caught my eye. It said
Office
for
rent
LOST
COW
Huh. Who loses a cow in Telford?
Then I looked again
Office
for
rent
LOW
COST
Who knew you could see a spoonerism.
Si
Maybe not the same thing but I once saw a sign wrapped round a circular wall in Liverpool that said…
“crap for sale”
As we drove past the ‘s’ revealed itself from behind a pillar.
Well, you did say it was in Liverpool 
Si
Many overpasses in NC have a warning sign saying, “Bridge ices before road” meaning that the bridge cools down quicker than the ground and therefore gets icy and slick even when the road is still good.
Thanks to a coworker, I now see these signs as saying, “Ice bridges before road.” He said that was how he always saw them and now I do too.
Again, not quite the same. When we visit the in-laws, we pass a fish hatchery. It’s the Deer Creek hatchery. One day, the sign caught only part of my eye. It is now, officially (in our car) the deer hatchery. I once, inadvertently, used it as a landmark when giving directions. Needless to say, They asked someone else for directions.
More like Hypno-Toad’s example, on long highway drives, when I come across the yellow warning diamonds that say “Slow Trucks” I always wonder, in my micro econmy car, “How the hell do they expect me to do that?”
“Slow children at play”
“Slow Men Working” – well, at least the kids have jobs waiting for them.
My favorite misread sign: while driving past a downtown church I spotted a sign that read, in big red letters, “ST RAGE.” I had time to run through all the catalogue of saints I knew before I drove past the pole that had been obscuring the ‘O.’
Not that there haven’t been angry-ish saints, mind you, but the sign was advertising a warehouse next to the church.
I remember being in the car when my dad was driving once, and he started laughing for no reason any of us could see.
He then explained that he had glanced to the side of the road to see a strip mall that had an “El Torito” Mexican restaurant next to an “All Star Video” rental shop, and he had seen “El Starvo” and it had struck him as funny, especially since we had eaten at El Torito and El Starvo was an appropriate name for it!
We never eat at the chain Italian place on the corner - O-Evil Garden much less the seafood place, Red Slober.
Need I mention how many people accidently read the “Publix” grocery store sign?
A long-haul trucker called DART uses a logo with big black letters and red arrow shapes zooming out from behind the D and the T. They used to use the same logo with much shorter red arrow shapes which ended just outside the letters, and made DART look like BARF.
PICK-A-BAGEL on NYC’s Upper East Side.
Come at it from across 2nd Avenue and slightly to the south (jaywalking, natch 
) and some obstruction in the way (lamppost? another sign? I forget) renders it ICK-A-BAGEL.
Excellent bagelry, BTW, not ICK at all.