With all of the options out there for a speed measuement, how do police departments deciede which device(s) to supply their patrol vehicles with? I notice that some are using various Lidar(s), some have Ka, X band, etc. There seems to be some degree of consistancy in some jurisdictions, but some police departments use everything in the book. (WI,VA for example) Is there any way to find out what they are using in any particular area? I hope anyone who knows the facts on this topic would please respond.