Traffic data (such as traffic volumes, vehicle speeds and accident history) is used alongside predefined criteria to determine if further investigations or traffic calming measures are required to improve safety and usability. These criteria are also referred to as ‘traffic warrants’. For example, if traffic data shows speeds are exceeding the thresholds outlined in the agreed criteria, further investigations and action may be required to reduce speeds.
Traffic warrants are based on a combination of objective measures and community perceptions.
Objective measures include factors such as traffic volumes that may cause delays, speeds that make it difficult for pedestrians to cross safely, or conditions where it may be unsafe for cyclists and vehicles to share the road.
Community perceptions are also considered as there is often a point at which residents begin to experience traffic as a problem. This understanding is informed through community feedback and LATM investigations across the City of Unley.
In addition, the role and function of a street is an important consideration. For example, streets near schools may experience higher traffic volumes during peak times.
Based on the definitions for three levels of warrants outlined in the Austroads Guide to Traffic Management, as well as an understanding of community perceptions and expectations, the City of Unley has developed the table below to guide when further investigations may be warranted for local streets.
This table shows the City of Unley traffic warrants for deciding whether further investigations or action is required.