Gerald,
If you are having your day in court because you are pleading innocent to that which you have been charged, may I make a suggestion? Put the odds largely in your favor by getting a continuance for your court date. A good reason would be you cannot get off work, car maint., your grandmother is dying, you know...something legitimate.
Request as many continuances (extensions) as they will give you. I have gotten 2 before. What this does is substantially lower the chances the policeman will actually show up, leaving you free of any charges automatically.
Most policeman try to schedule their court appointments together, and most often NOT on a day off. If you extend enough (fully legal) you may catch him on on day off, and he will likely blow the entire thing off.
Call the issuing courthouse and get a continuance so you can "gather more evidence".
Good luck-
Rollo