I talked to some guys from IDOT. They seem to think, they can not pin point exact location just the vicinity. They all so think the mic has to be keyed. There is nothing in the yards office that they see.
Thanks for the reply, I talked to a "Snow Bird" in Piatt county and he told me the district office will have the ability to track the trucks on a screen. With the Starcom 21 system the computer that keeps track of the location of the radios will come into play when the trucks move from location to location,I do not know if the mike has to be keyed or not. There is some information on how the system operates on the State of Illinois Dept. of Central Management Service web site, I will try to find it and post it. I worked for IDOT for 25 years in Dist 5. and enjoyed plowing snow! Be safe!