Collisions between vehicles, and between machines and people on foot, are among the leading causes of serious injury and death in mining. Training, signage and traffic rules reduce the risk, but they all depend on people noticing a hazard in time.
Proximity detection adds an engineered layer that does not rely on the operator's line of sight. This guide explains how it works, how the main technologies compare, and how to deploy it so operators trust it.
Why engineered controls matter
Safety professionals rank controls by effectiveness. Eliminating the hazard comes first, then engineering controls, then administrative controls such as procedures and training, and finally protective equipment. Traffic plans and speed limits are administrative controls, which depend on human behaviour every time. Proximity detection is an engineering control, so it still works when someone is tired, distracted or cannot see.
The main technologies compared
- Electromagnetic field systems, such as Strata's HazardAvert, generate a field around the machine. A tag worn by the worker detects the field, so both the worker and the operator are warned. They work without a line of sight, including in dust, darkness and around blind spots.
- Tag-based radio ranging systems estimate the distance between a machine and tags carried by people or fitted to other vehicles. Performance depends on the radio environment and how the system is configured.
- Camera and AI systems, such as SafeSITE HazardAI, use machine vision to detect people and objects. They can identify what is in view, but they need a clear view of the hazard.
No single technology suits every machine and every environment. Many sites combine them, for example electromagnetic detection on haul trucks and cameras on machines with large blind areas.
Designing warning and stop zones
Zones are the part of the design that decides whether operators trust the system. Typical systems use at least two: a warning zone that alerts the operator and the person, and a stop zone that can slow or stop the machine.
- Size zones for the machine type, speed and stopping distance, not for convenience.
- Avoid nuisance alarms. If operators hear alarms for people who are not at risk, they begin to ignore them.
- Tune zones on site during a pilot, with operators involved, and record the settings.
How it fits Ghana's traffic control requirements
L.I. 2182 contains several provisions that a proximity detection programme sits alongside:
- Regulation 99: a written traffic control plan covering maximum speeds, routes, vehicle priority, barriers and restricted areas, emergency procedures and training.
- Regulation 84(3): signs and other devices to control the speed and movement of vehicles on mine roads.
- Regulation 104: audible warning devices on motor vehicles where clear vision is not available, and an automatic reverse-gear warning device.
- Regulation 159: vehicles must have an unobstructed view in the direction of travel, or guidance from authorised persons giving suitable signals.
- Regulation 465(4): in opencast mines, transport rules posted conspicuously and given to all drivers and operators.
Proximity detection supports these controls with an engineered layer of protection. It does not replace the traffic control plan.
This is a plain-language summary for general information, not legal advice. Regulation numbers refer to L.I. 2182. Always check the current regulation text and Minerals Commission guidance for your operation.
Rolling out proximity detection
- Survey the fleet, haul roads, intersections and work areas, and identify the highest-risk interactions.
- Choose the technology for each machine type and agree zone sizes.
- Install and commission on a pilot group of machines, with operator involvement.
- Train operators and ground workers on what the warnings mean and how to respond.
- Review alarm data after the first weeks, adjust zones, then scale to the full fleet.
Questions to ask a supplier
- Which certifications apply to my application, for example for underground coal or hazardous areas?
- How does the system integrate with vehicle telemetry and fleet management?
- How are tags managed, charged and replaced across shifts?
- Who provides local installation, calibration and spares?
Frequently asked questions
Is proximity detection required by law in Ghana?
L.I. 2182 requires traffic management controls such as a written traffic control plan (regulation 99) and warning devices on vehicles (regulation 104). It does not prescribe a specific proximity detection technology, but it is a recognised engineered control that supports those duties.
Does proximity detection work in the dark and in dust?
Electromagnetic systems do not rely on a line of sight, so they continue to work in darkness and dust. Camera-based systems depend on visibility, which is why many sites use more than one technology.