Input Dataset

NSW Road Segment Dataset


Road segment represents the centreline of a section of road, having common attributes and terminating at its physical end or to an intersection with another road at the same grade or level. It is an open way for the passage of vehicles, person or animals on land. Road segment is a line feature class of the NSW Digital Topographic Database ( DTDB), within the Transportation theme. Road Segment has the following Subtypes:
Standard Road;
On Off Ramp (only access ramps associated with roads of arterial or higher status and generally longer than 100 metres are identified);
Dual Carriageway;
Roundabout (only roundabouts with a road centreline diameter greater than 15 are identified);
Vehicular Track (including driveways , generally only passable in two-wheel drive vehicles during fair weather and are used predominantly by local traffic, or 4WD vehicles if the road's surface is attributed as Unsealed: Four-Wheel Drive);
Pathway ( for use by pedestrians, horse riders and/or cyclists);
Continuity Line (used to maintain linear continuity of a road name through a roundabout or over water (e.g. ferry) and does not represent a physical road centreline).

The road classification scheme is based on the importance a road has within the total road network ( Road Function Hierarchy). The functional hierarchy used in the database is based on the definitions from Intergovernmental Committee on Surveying and Mapping ( ICSM). The hierarchy identifies:
Motorways (high traffic volume and speed with no direct access only via ramps which may or may not be ‘declared’ motorway, freeway or expressway);
Primary roads (major interstate route or connecting road between major centres, mostly National or State Highways with a few exceptions)
Arterial roads (major connectors between Freeways, Highways, major centres);
Sub-arterial roads (connectors between primary or arterial roads, or smaller localities);
Distributor roads (major traffic movement between roads of higher order or to local streets);
Local roads (sealed or improved unsealed road providing property access);
Urban service road (one traffic lane in an urban area that does not service a building frontage and is not used for postal addresses);
Track-vehicular (an unimproved road, including driveways which are a subset of the Road Segment subtype Vehicular Track, the difference being Vehicular Track is a classification of road physical form, whereas Track-Vehicular is part of a classification based on highest function);
Path (replication of Road Segment class subtype pathway, and is used by pedestrians, horse riders and/or cyclists);
Dedicated bus way (does not include those ways that are merely a bus-only lane of a shared road); and,
Access way (accessible by major service providers to maintain their infrastructure, and emergency service agencies. The practical operability of these roads is unknown and there may be no physical formation and may be affected by locked gates. For example, an access way may be an unmarked route across a sports field or car park).

Other important attributes within this feature class include:
Lane Count (an indication of the road width but does not indicate the total number of lanes, instead are classified as one lane, two or more lanes, or unknown lanes);
Road Name Base (as defined by AS4212-1994 & AS4590-2006 Road Addressing Standards. e.g. 'Prince' in Prince Street West);
Road Name Extent OID (the unique OBJECT ID of a feature in the Road Name Extent feature class);
Road Name Suffix (the SUFFIX component of a road name as defined by AS4212-1994 Street Addressing Standard. e.g. 'West' in Prince Street West);
Road Name Type (the TYPE component of a road name, as defined by AS42 12-1994 & AS4590-2006 Road Addressing Standards. e.g. 'Street' in Prince Street West);
Road On Type (a section of road associated with a supporting structure such as bridges, tunnels etc.); and,
Surface (road surface type of Unknown, Sealed, Unsealed, Unsealed

Dataset Purpose

The DTDB is primarily used for planning, developmental activities, navigation and resource monitoring by emergency services, the Defence Forces, environmental resource managers and engineers. This information is also commonly used by bushwalkers, canoeists, anglers and fossickers to establish a detailed picture of the local environment.

Funding Support

Access Mechanisms

Online, online Services, Email, FTP, Post VAR

Access Format

GeoDatabase(gdb), Shape(shp), ESRI SDE, Well Known Text(wkt), Data Exchange Format(dxf),Oracle(SDO), MapInfo(MID/MIF/TAB)

Dataset Lineage

The original mapping information that constitutes the DTDB was initially created from 1970 at 1:25 000, 1:50 000 and 1:100 000 scales from stereoscopic aerial photography supported by ground truth, field data capture and updating. These scales have an inherent accuracy as per the National Mapping Council of Australia, Standards of Map Accuracy (1975). Therefore, the position of the feature instance will be within 0.5mm at map scale for 90% of the well-defined points. That is, 1:25000 = 12.5 m, 1:50000 = 25 m and 1:100000 = 50 m. The original manuscripts were scanned and vectorised and translated to Genamap files. Beginning in 2004, the data was migrated to an ESRI geodatabase. Since then the database has been continuously updated and upgraded through a program of external data integration from custodial and other sources, data matching and data verification of other internal and external databases, field investigation and research, as well as through Land and Property Information (LPI)’s regular cycle of updating aerial imagery of 10 cm, 50 cm and 2.5 m GSD. The programs address the content correctness, currency and accuracy of different Feature Classes on a continuous or cyclical basis. The specific programs utilised for the maintenance of each feature are largely defined by the Capture Source Attribute attached to the feature. Data is updated via multiple source programs and captured using various methods; Registered Image Trace, Ortho Image Trace of 10 , 20 and 50 cm ground sample distance imagery from ADS and 2.5 m from SPOT 5 imagery , Table Digitisation , DCDB , Scan / Vectorise , Differential GPS , Non-corrected , Comparative estimate , Survey Controlled , Mobile GPS , Stereo Image Trace Aggregation or replication of existing line segments , Engineering Design File (CAD) Scanned Map Image Trace , Positioned within features cadastral or ortho image extent. Some capture methods are unknown which may occur where data was supplied by an external source where the data capture method is undefined. Depending on the capture source, capture method, digital update and control point upgrade, every feature instance reportedly has a positional accuracy within the range of 1 m-100 m. It is important to note that not all features may be captured within the database for each feature class, and may not be an accurate representation of the current state.

Access and Licensing

Identified Mandate


Content Source

National datasets