New advanced signage has been installed at the often problematic Blundell Aqueduct in Edenderry.
The aqueduct, located on the Edenderry to Rathangan road, is the only structure in Offaly that carries the canal over a road.
Built in 1793 as part of the Grand Canal, it is a protected structure and is seen as having regional importance.
The route is impassable by HGVs but has been the scene of numerous incidents of vehicles becoming stuck over the years.
In 2011, it made national headlines when a prison van carrying prisoners got stuck underneath it. Air had to be released from the tyres to release the vehicle.
