I have some experience with your problem ! Police is only part of your problem.The first thing you need to do is download the RADIUS DOUBLER for your schools,Police,fire,ect...... found here www.simtropolis.com/stex/details.cfm=13696 Or go to the search at simtropolis and type in Radiusdoubler ,mark it entire site and hit go.
This will HELP GREATLY with the radius of your police stations,my station is not even close to the airport.
Next this is the most important of all! If your airport is too long a commute for both workers or COMMERSE,especially commerce business will be LOW and cause problems.SO keep the airport close to lets say 40 tiles away from your nearest COMMERCIAL district and you want a STRAIGHT driving path from commerce to Airport no turns if possible and the commuters will love you.Keep building your COMMERCIAL UP,UP,UP ! Remember the airport thrives on the commercial.Infact my particular city Im useing has no INDUSTRIAL.
One finale note:This works so well for me,I actually put the airport in my city before i started anything,and if your wondering about air pollution it is compleately surrounded by trees,I do this with the flora in god mode before starting the city.
