Police call will 'get you by' however I'd much rather have the county pages from RR.com. Usually I've found, if you can find an agency with PL's listed, and such... it means that info has been submitted by a user, and is usually very accurate.
Police call goes by licenses, and not all agencies use all licenses, and often times changes have been made that arent reflected in police call.
Figure out what counties you're headed to, and print them out. It'd be your best bet.
I *had* heard that contributing (donating) members would be able to some day download a txt or .csv file of the counties, but I think that's still in the works.