It's time traveler code for "when this baby hits 88 miles per hour".
It's a libertarian crossing sign. It reminds you that the government can't make a decision for you, and that you must take responsibility for your own life in matters small and large.
... ... and be wary of pink-eye (the last digit seems pink in the sign) ... in your traversals, so that your comments don't appear to smell up the place, when your just trying to connect to some LISPers ... instead of drilling down on the image at hand ...
This sign warns to watch out for palm sized people. Look down!
the sign says " If you think you can make it accross the street in the this remainng 1 red-second left that I have made left available to you ,then you should feel free to take the chance that you can complete your journey to the other side without complications, but should you encounter any resistance, just know that they were not something that this sign had a hand in producing"