Press the green flag. Click Blues for lights and sirens. When Blues are active press H to change sirens. Usually you just get a normal speeder but you get the odd pursuit but they dont last long. A speeder is someone in the right hand lane (emergency lane.) When you see that click blues to go in that lane and chase them! Enjoy! (ps this is my fav game) WARNING: THIS GAME CONTAINS FLASHING IMAGES
Credit only to LinuxStudent for all of the scripting. The star and heart buttons are lonely, why not give them a friend by clicking them?