Construction of gantries
Gantries are the overhead structures used to support mounted Variable Message Signs, Lane Use Management Systems and Closed-Circuit television (CCTV) (video security surveillance).
In April, the R2P Project commenced removing six existing gantries along South Road and the North-South Motorway, between Overland Road and Camira Street.
In June, piling works commenced for the 21 new gantries.
Two methods of piling are being used for the installation of the new gantries:
- bored piling methodology for piles five to six metres deep into the earth; and
- continuous flight auger (CFA) piling for piles up to 13 metres deep into the earth.
The new North-South Motorway gantries include:
- portal gantries – span across all lanes in one direction or across the entire surface road or North-South Motorway;
- canter lever gantries – extend across lane(s) travelling in one direction; and
- canter lever poles – extend out to a lane from the pole and are located on the northern and southern sides of the North-South Motorway.
The gantries provide both operational and safety benefits, including:
- allowing flexibility for individual lane-based directional or speed limit signs;
- allowing for increased visibility of directional and speed limit signs in all lanes; and
- removing the potential for signs to be obstructed.
The installation of the gantries is expected to be completed in late 2020, weather permitting.