Title

Vicmap Transport - Road Use Table 

Alternate title

TR_ROAD_USE 

Purpose

To display trail names and ignore road names associated with a single network segment it is necessary to qualify the ROAD_NAME with a road use. 

Supplemental Information

Related Documents: None www.delwp.vic.gov.au/vicmap 

Status

Completed  

Horizontal Accuracy

25m  

Code

4283 

Maintenance and update frequency

Continual  

Topic category

• Structure
• Transportation

Use limitation

. 

Classification

Unclassified  

Statement

Dataset Source: The line work and points were derived from the Vicmap Digital Topographic (VDT) map base coordinated by Information Services Branch (ISB) and its predecessors. Road network was updated using aerial photography and setellite imagery. In built up areas such as large rural townships the road centreline derived from VicMap Digital Property was used. Dataset Originality: Derived 

Description

Collection Method: Conversion of existing mapping, digital stereo capture 

Description

- Conversion of existing mapping - compilation conversion 30% and repromat conversion 50% - digital stereo capture - 20% -The majority of the conversion of existing mapping and approximately 30% of the digital stereo capture were outsourced to private contractors and the remainder was captured in house. Contractor's primarily scanned and vectorised existing repromat with a small amount of hand digitising done in some instances. 

Classification

Unclassified  

Attribute Quality

Comments

The allowable error in attribute accuracy ranges between a 1% allowable error to 5% error. For this product attribute accuracy ranges between a 1% to 5% error. For this product attribute accuracy is a measure of the degree to which features and attribute values of spatial objects agree with the information on the source material. There are some issues to be addressed with: walking tracks 

Positional Accuracy

Comments

The planimetric accuracy attainable will be the sum of errors from thee sources: -the positional accuracy of the source material -errors due to the conversion process -errors due to the manipulation process The measure of accuracy given for 'Road Network - Vicmap Transport' data is the source scale of the mapping from which the digital data was initially derived. Source map scales, vary from 1: 2,500 to 1:25,000. It is not possible to guarantee the final planimetric accuracy of 'Road Network - Vicmap Transport' other than estimate possible errors due to the positional accuracy of the source material and data conversion and manipulation processes.A conservative estimate of 5m and 20m for the standard deviation of the SDRN within the Melbourne Metropolitan area and Rural areas respectively will be used in any data quality information.Alternate and equal ways of expressing this error are:Not more than 10% of well defined points will be in error by more than 8.2m for the Melbourne Metropolitan area and 33m. for rural areas.The worst case error for the data is 15m for the Melbourne Metropolitan area and (60m for Rural areas). 

Conceptual Consistency

Comments

The allowable error in attribute accuracy ranges between 1% to 5% error. Logical consistency is a measure of the degree to which data complies with the technical specification. The test procedures are a mixture of scripts, microstation MGE program and on-screen visual checks. 

Missing Data

Comments

Apart from features that are subject to selective revision, the primary source material is existing digital from a number of sources: - road centerline data from Vicmap Digital Property cadastral base and Vicmap Digital Topographic bases. All instances of a feature class and its attribute values that appear on the source material have been captured.unless exceptions are indicated in the selection criteria for that feature class. The completeness of the data is tested by overlaying symbolised plots of the VDR digital data over plots of the source digital data and carrying out a visual comparison. Where it is allowable for up to 1% of features to be missed in data capture, the entire population is tested. Where it is allowable for up to 5% of features to be missed in data capture, then a random subset of the relevant features in the tile is tested. The sample's size is determined using statistical tables using the known population size of the relevant feature. There are some issues to be addressed with: walking tracks (50% missing) 

Excess Data