Not an exhaustive list since it doesn't include all districts but searching that range should probably hit on something. Then you can submit it to the db to be updated, if you find it.
[Ignore the AHP frequencies...they are deprecated]
It's 156. something. I'd have to look in my history to find it. It's close enough that it was bleeding over on some of our public safety frequencies during the last weather event.
They have simple analog VHF radios in their trucks (Icom, Motorola, and even Vertex) and single quarter-wave VHF antennas on top. We have numerous trainings on the campus where I work and I have looked in dozens of their trucks - no P25 anywhere.
AHP uses AWIN but not the highway dept (ArDOT) as the OP was asking.