You do know sirens are not effective at highway speeds right...? Mechanical sirens are a fraction more effective however they still get overdriven quite quickly.
All in all you just need good pre warning (sign boards, construction signs, lane closure signs, arrow boards etc) and good construction markings and crash trucks blocking any lanes. Have a pd unit with lights active if one wants (drivers sometimes will heed emergency colors better than amber) but the pre warning and lane closure arrow/crash trucks are paramount.
Oh and proper pylons as well.
All in all you just need good pre warning (sign boards, construction signs, lane closure signs, arrow boards etc) and good construction markings and crash trucks blocking any lanes. Have a pd unit with lights active if one wants (drivers sometimes will heed emergency colors better than amber) but the pre warning and lane closure arrow/crash trucks are paramount.
Oh and proper pylons as well.