Okay, in order to help you, why don't you provide the following:
1: City, Town, Village, County, State you reside in.
2: Significance of the highway mentioned
3: Type of service(s) wishing to be monitored to ascertain type of scanner needed for conventional, trunking, analog, digital, etc.
4: Preliminary decision on type of scanner, Tabletop, Mobile, Portable
5: Preference of Manufacturer and/or Model
6: Spending ceiling.
Also have you checked the database for your state & the WIKI section to familiarize yourself with all aspects of the hobby? This may sound like a tall order however the more information you can provide, the more you can be helped.
[!] The man formerly known as FLRAILMAN