#81 Area-wide vulnerable road user (VRU) treatments (part 1)

Vulnerable road users (VRU) can be broadly defined as road users at a significantly elevated risk of injury in the event of a crash when compared with other road users (i.e., occupants of cars, trucks, buses). Their vulnerability is often exacerbated by high exposure to crash risk in some environments, typically where traffic conflicts are frequent and/or infrastructure is poorly designed or maintained. Pedestrians and cyclists are the two main road user groups addressed in relevant VRU reports and guidelines, although much research historically has also included motorcyclists as VRUs due to their lack of physical protection. Additionally, with the recent proliferation of e-bikes and e-scooters, the traditional line between bicycles and motorcycles is increasingly blurred, presenting further challenges for both planners and regulators.

The current series of briefs looks at VRU treatments as part of an area-wide approach, drawing substantially on the Austroads (2020) report titled Integrating Safe System with Movement and Place for Vulnerable Road Users[1]. Indeed, an area-wide approach to VRU safety must be intrinsic to Safe System implementation, Network Safety Plans, and the application of Movement and Place and related principles. The series is structured in four parts, including:

• Part 1: Introduction to the series (current brief)

• Part 2: Cyclist safety measures

• Part 3: Pedestrian safety measures

• Part 4: Motorcyclist safety measures

Guiding principles

As indicated above, area-wide safety measures for VRUs should be consistent with Safe System principles and related frameworks such as Movement and Place. Austroads (2020, p.8) acknowledges that:

… road users will inevitably make mistakes, and when they do, they should not be penalised with death or serious injury, it follows that road designers and operators have a shared responsibility to take appropriate actions to ensure that road crashes do not lead to fatal or serious injury outcomes.

One of the critical keys to Safe System implementation is the application of low speeds, especially where mixed use of travel modes occurs. Of course, it is always better to prevent a collision than to reduce its consequences, but both objectives can be met with appropriate speed limits. For vulnerable road users (excluding motorcyclists), 30 km/h is cited as the ‘aspirational’ operating speed where a collision with a motorised vehicle is possible. While estimates vary on the thresholds for fatal and serious injury risks, they are largely consistent with the chart reproduced in Figure 1.

Figure 1: Relationship between collision speed and the probability of a fatality (Source: AP-R611-20)

Measures for pedestrian and cyclist safety and their alignment with Safe System principles for different (non-intersection) location types are summarised below in Table 1. Treatments for intersections are separately identified in Table 2. These treatments will be looked at in further detail in parts 2 and 3 of the series.

Table 1: VRU safety measures (non-intersection) and alignment with Safe System principles

(Source: AP-R611-20)

Table 2: VRU safe intersection measures and alignment with Safe System principles

(Source: AP-R611-20)

Key references for further reading

• Integrating Safe System with Movement and Place for Vulnerable Road Users (Austroads, 2020)

• Speed Zoning Policy and Technical Guidelines (Victoria, 2025)

[1] Austroads (2020). Integrating Safe System with Movement and Place for Vulnerable Road Users (AP-R611-20). Sydney, Austroads.