Why is traffic management important?
Traffic on mine sites needs to be managed to reduce the risks associated with vehicle and pedestrian movements, especially interactions between light and heavy vehicles, and pedestrians and vehicles, and to maintain cost-effective and efficient traffic flow.
Managing the risks
Traffic management plan
To achieve and maintain a safe traffic system, a traffic management plan should be developed to manage the risks present in mining operations. It should address items such as:
- road and intersection design factors such as gradients, road surface material, visibility, type and volume of traffic
- common and specialised traffic signage, markings, delineators and barriers
- site or company policies or protocols for functions such as speed limits, overtaking, road rules (e.g. give way), communication and parking
- the management of human factors and fitness for work (e.g. fatigue prevention and management)
- vehicle design, modification and maintenance strategies
- schedules of inspections and auditing
- when the plan is updated and by whom
- change management.
Wherever practicable, engineering solutions should be sought to reduce the potential risks associated with road user behaviour or operator error.
Some strategies for traffic management are discussed below.
A code of practice for safe mobile autonomous mining in Western Australia is under development and may assist when developing a traffic management plan for autonomous operations.
Working with or near large mobile plant
The size, inertia, weight and power of mobile machinery used in mining present significant hazards to people and equipment in their area of operation.
In particular, the operator’s restricted view of the surroundings and the extensive range of vision shadows or blind spots can mean that people and objects are hidden from sight. All mobile equipment has blind spots. The people most commonly at risk are supervisors, spotters, and service and grade control personnel.
Develop a traffic management plan based on a risk assessment. Where practicable, minimise or eliminate:
- the need for reversing of large mobile equipment
- light and heavy vehicles interaction by reducing the number of pit permits or providing segregated transport routes.
Pedestrians and walking are part of every journey and are present on all sites. Walking is an effective and practical transport mode but it also involves the most vulnerable road users, which means the interaction with vehicles or other road users should be managed carefully.
Risk factors include:
- interaction with other road users
- no separation from vehicular traffic
- pedestrian infrastructure that does not match the desire lines (preferred pedestrian access routes based on convenience of travelling from one location to another)
- poor communication protocols
- hazard delineation
- access control for hazardous areas.
There is also the need for:
- the provision of escape routes
- awareness of
- site rules
- personal hazards
- behavioural issues and risk taking
- appropriate use of personal protective equipment (PPE)
- health or fitness limitations.
In order to address the risks associated with pedestrians and maximise the benefits associated with walking, a comprehensive pedestrian management strategy should be developed.
Pedestrian needs should be considered for the various stages of a project. Addressing pedestrian requirements during the design stage is always the preferred option as it increases opportunities and negates the needs for more expensive retroactive measures to be implemented in the future.
The goal of speed management is to minimise risks associated with driving at speeds that are inappropriate for the prevailing conditions.
This can be achieved by establishing appropriate and safe speed zones together with developing measures for ensuring compliance with speed limits on mining operations. Where practicable, create a traffic environment as similar as possible to conditions that drivers encounter on the public road network. Drivers have been trained and conditioned to follow the rules and regulations that apply on public roads and therefore behave and respond better to traffic inputs that are familiar.
Special consideration should be given to areas with high levels of interaction between pedestrians and vehicles, such as car parks, administration areas, workshops and processing plants.
In terms of speed management overall, factors to be considered include:
- setting appropriate speed limits taking into account
- where possible, limiting the number of speed limits to three or four (e.g. 10, 20, 40, 60 km/h)
- preparing speed zone maps
- monitoring and enforcing compliance
- responding to changing environments
- unsealed roads (e.g. dust, rain, wind)
- driving to conditions.
A comprehensive speed management strategy is only partly achieved if there are no effective measures in place to ensure compliance with the requirements.
Site management can implement a number of measures to work towards lowering the risks associated with speeding and unsafe driving behaviour, and encourage compliance with the applicable road rules. Such measures include procedures, engineering modifications and behavioural modification. Examples of compliance measures are described below.
Use to physically slow traffic (e.g. narrowing sections of roads, installing speed humps, using in-vehicle speed monitoring systems).
Undertake regular activities to promote the importance of compliance with speed limits and raise awareness of the serious consequences associated with speeding.
Establish realistic and simple speed zones that are easy to comply with.
Speed checks can be used to modify road users’ behaviour, either as random handheld radar checks or by using portable speed radars with variable message signs to give feedback to drivers about their speed.
Enforcement and disciplinary actions
Should be used as a last resort measure to show management considers speeding to be an unnecessary risk-taking behaviour that will not be tolerated.
For its part, mine management should ensure that:
- vehicles provided are fit for purpose
- roads and road infrastructure are constructed and maintained in a safe condition
- there are no unsafe or impractical speed limits in place
- there are no work pressures that would require drivers to speed
- the road environment is forgiving to those who make genuine mistakes and lose control of their vehicles.
Signage is an important part of the road network as it advises drivers about all kinds of rules or potential hazards. Intersection and speed signs are most commonly used. However, signage at mine sites is commonly not addressed centrally and consistently. The use of roads within the mine site can change, and the signing needs to be updated to reflect current road conditions.
There should also be a signing maintenance program or central point for ordering signs to ensure that they conform to the basic standards of:
- appropriate size
- adequate reflectivity
- being fit for purpose
- being easy to read and understand
- where possible, conforming with Australian Standards.
Where possible, traffic signs on mine sites should be installed in accordance with Australian Standard AS 1742.2 Traffic control devices for general use.
Road users usually best respond to traffic controls that they encounter in normal circumstances. The use of non-standard signs should be restricted to those applications where the required message cannot be adequately conveyed with a standard sign.
Australian Standards are available from Standards Australia.
A four-part audit for mobile equipment is available, including Part 1 on traffic management.
Autonomous mining operations are not covered in the audit.
Please refer to related information below:
Main Roads Western Australia has a section on road and traffic engineering that includes traffic management.
Austroads has a number of publications including a Guide to road design.
The Unsealed roads manual - Guideline to good practice is available for order from ARRB Group.