Legal Question in Traffic Law in Illinois

Re: Subpoena Infor

As a general rule, you need to subpoena any documents or witnesses that you intend to use or call at trial. Often, the state will subpoeana the arresting officer to testify at trial; the arresting officer's testimony is usually required for the state to prove you guilty of speeding beyond a reasonable doubt. It is doubtful that the state would need to subpoena any other records or witnesses to prove its case.

Accordingly, if you want additional reports or the testimony of any witnesses not already being subpoenaed by the state, you would need to send out the subpoeanas.

As far as to whom you would send a subpoeana to get the engineering speed survey for a particular location, I'm not sure. That information may be in the possession of the city or county where the road is located. It may also be in the possession of a construction or engineering firm responsible for the area in question.