Two vehicles have collided with barriers at upgrading works on the M7 Co Kildare in the past week alone.
From Monday, two speed vans will monitor the route to deter motorists from breaking the speed limit.
Gardaí say there have been a number of very serious incidents since works started on the M7 between junction 8 and 11.
This week alone a truck crashed through a barrier to avoid slowing traffic up ahead while a van hit a barrier and landed in the works area.
The speed limit is 60 kilometres an hour while works are in place but cars often break it.
Over 500 motorists have been caught speeding and 32 motorists have been prosecuted for dangerous driving.
As a result, two GoSafe Vans will monitor the route from Monday to encourage motorists to slow down.