ltl, here is the charge;
http://law.justia.com/us/cfr/title36....4.0.1.12.html
I am aware of the difficulty you are arguing. At times, yes, the federal constitution requires a "Notice".
Here, you can argue, since there was no point of entry notice, Due Process was violated. Now they will counter with since a person is "presumed to know the law", did you know the speed limits applicable when you entered federal property and if you knew you entered, which you have complied?
It would take further detailed research to come up with a better defense, but the DP clause is a start.
This is part of my DP argument. Here in Ohio a municipality can refuse a right turn on red, even though state law permits it, BUT, the Ohio Supreme Court has ruled that a NOTICE, meaning a Sign, MUST forbid it as not to confuse a motorist. They simply can't have an Ordinance forbidding it and "presume" a motorist knows the laws in every Ohio Jurisdiction; State v. Parker (1994?)

