Speed limits are set in accordance with Victorian Speed Zoning Guidelines which are developed and applied by road safety experts and traffic authorities. They are based on international evidence-based best practice, engineering standards and guidance, state legislation and government policy.

Key factors considered in setting speed limits on a particular road or area include: crash history, road and roadside characteristics, road function and use, and the presence of vulnerable users. All of these factors are based on road safety risk but still consider the need of people to make journeys.