What is this thing?

They started installing poles along a main road near where we live and I’m not sure what the white antennas on them are for. Some of the poles have traffic cameras like the one in the picture but others don’t. They are spaced every half to one mile and have antennas on opposite sides, with what looks like a radio cabinet near the base. The antennas are all aligned along the road, pointing parallel to traffic. This is in southwest Pennsylvania.