Digital Road Centre Line (DRCL) Survey

SCOPE:

All Queensland Roads are currently maintained under ARMIS (A Road Management Information System). The need to update this system and to provide a spatial relationship for the roads, has seen DSS undertake road addressing and gazettal on most roads throughout central Queensland.

DSS's METHODOLOGY:

Positions along the road centre lines are recorded at 25 metre intervals, allowing for the reduction to accurate Gazettal chainages. Besides the road centre line, other features and points of detail in the survey include, but are not limited to:

* property accesses
* culverts, formed floodways
* bridge abutments
* traffic signs
* grids and gates
* road intersections
* existing survey reference stations

Specialised software developed by DSS is used to determine a chainage along the road centre lines, generated using the following formula, this represents the true driving chainage along the road.:

Chainage increment = (Easting² + Northing² + RL²)

GPS information provides accurate coordinates so a map can be generated and overlaid on existing topographic or other maps of the area.

The resultant chainage calculated from the previous formula, is linked to a feature output file to generate accurate Map Grid of Australia (MG94) and Australian Height Datum (AHD) coordinates and chainages for all assets located.

Comments are coded by the client, and DSS, which integrate with the current information system. This information is only one example of what DSS can produce, any format of information is possible.

Connections are also made to cadastral marks in the field so that road information ties in with the boundaries of properties and road easements. Local Government Control is used for the control surveys and this provides the survey with an accurate, first-order datum.

Numerous graphs can be formulated from this raw information to aid as design tools and allow for future planning. A simple road profile plot, as shown on the following page, is a useful tool for culvert design and drainage purposes. GPS heights and centre lines are surveyed to an accuracy of better than 0.1 metres so the information is very reliable for design purposes.

Recently commpleted DRCL's include:
> Capture of Digital Road Centrelines for the Mackay District > view