Operational requirements often dictate that mining activities take place in different areas of mines. This requires mining fleets to move to different areas and use different haulage roads. It is important that risks associated with a changing road environment are recognised and appropriately managed. Mining operators should engage in a proactive management of their road networks and road closures, temporary or permanent, should be part of the mine operator’s toolbox.
For example, due to blending requirements, a specific type of ore may be sourced from one pit and then a different ore type needs to be mined in another pit. On some mines these changes take place every few months while on others, mining activities change location during a single week.
These changes can result in mining road networks consisting of numerous roads, intersections and accesses to areas that are not used for either short or long periods of time. Sometimes, access to these ‘inactive’ areas is not delineated, sometimes it is only demarcated, and sometimes access is prevented by installing hard barriers.
There are a number of safety and operational implications with extensive road networks and vehicles inadvertently accessing inactive areas, such as:

• increased demand for road maintenance
• vehicles accessing roads or areas that are not maintained
• uncontrolled access into hazardous areas
• complex networks with numerous intersections that can be confusing for drivers
• drivers can make mistakes if unfamiliar with changed road layouts
• roads affected by inclement weather conditions.

Ideally, a mining operation should have a robust (and practical) change management procedure in place. This procedure should differentiate between low risk and high risk changes (identified through a formal risk assessment). Based on the level of risk and the duration of the change, appropriate closure and delineation methods should be implemented.
For example, areas or roads that are not likely to be used for longer periods of time (e.g. seven days or more) should be barricaded off by using windrows preventing all access. A gap in the windrow can be provided if access is required for authorised vehicles (e.g. dewatering team, geotech, etc.).

Short term access restrictions (e.g. less than seven days) can be achieved by using witches hats or bollards and signage – unless a risk assessment demonstrates the need for a more robust barrier due to a specific risk in that area.

Witches hats, bollards and chains are sometimes used for all closures. These are not effective measures as they are not easily discernible, can be damaged or displaced and are easier to breach. On the other hand, windrows are a more robust, effective and defendable delineation measure for mining road closures.