Road Centre Lines

Lineage The road centrelines data was originally created via digitising the approximate centrelines of the road reserve areas extracted from the Digital Cadastral Database (Department of Natural Resources and Mines QLD).

This was later improved upon through field work which involved collecting/updating the road centrelines using a GPS tracking on a tablet to get the approximate centre of the road segments and the gazetted road name from the street sign.

Further to this, Rockhampton Regional Council now regular updates this dataset via digitising the roads from high resolution aerial imagery (10cm resolution for urban areas and 25cm for rural areas) Other methods of updating dataset is via utilizing the centreline data provided in As-constructed drawings that are provided to Council from external sources.

Full review/update of the dataset is performed when the latest high resolution aerial imagery becomes available to Council which is on average every 1-2 years. Positional Accuracy: The accuracy of the urban roads that fall within the main townships of Rockhampton, Gracemere and Mount Morgan are at a high standard due to them being corrected via 10cm resolution aerial imagery (2014). There may be inconsistencies in areas where there are substantial amounts of foliage/shadows covering the road in the aerial imagery, making it difficult to determine where the road is.

Rural Roads outside of these areas were updated using 25cm aerial imagery (2014) and As Constructed drawings.

Some process changes have occurred over the last several years such as the decision to split the roads around the median strips and include the connector / turn off roads as polylines as well. Majority of these have been captured there may be some that have been overlooked.

Attribute Accuracy: The defined road names around the region are of a high accuracy of correctness. There may be very few (1%) that may be different to the street sign, i.e. a spelling issue. Council continually corrects these discrepancies when found. Connector roads and roundabouts have no name assigned as they are there mainly for display purposes and continuity of the road network. Road names are validated from survey plans (which is the point of truth), from the street signs and can be validated by minutes of Council Meetings and many unnamed roads have been named by this method. There may be duplicate road names as multiple roads fall with more than one locality or township.

The attribute fields attached to the road polylines are as follows. FULLNAME – Contains the name and the abbreviation ROAD NAME – Contains just the name of the road ABREVI – Contains the abbreviated road type LOCALITY – Contains the road and the locality that the road is located in. DESCR – Used to describe other roads/streets that don’t have an official name. COMMENTS – Additional information attached to the polyline CATEGORY – Derived and simplified from the SYMBOL_LEVEL field (not included). This field is to describe the authority/designation of the road and is used for symbolising. Depending on the road line, not all of these fields will be populated.