Real-Time Worker Tracking on Large Construction Sites

On a large construction program, the safety team often cannot say exactly who is on site at a given moment or where each person is working. Most sites still rely on a sign-in sheet at the gate, a contractor list prepared in the morning and radio check-ins during the day. This works reasonably well on a single building with one general contractor. It becomes unreliable when the program covers several work zones, many subcontractors and overlapping shifts.

The problem matters most during an emergency. If there is an injury, an evacuation or a worker who does not answer the radio, supervisors have to compare paper lists with radio calls to work out who is missing. That takes time, and during that time nobody is helping the person who needs it.

Why manual tracking is hard on large sites

Large programs, such as highway projects, industrial plants, campus construction and energy projects, have a few things in common that make manual tracking difficult:

• Work areas change often. Zones open and close from week to week, so a fixed list of who works where goes out of date quickly.
• Most of the workforce are contractors. Crews change during the day, and the general contractor is responsible for people it does not employ directly.
• The site is spread out. On a project that covers several miles, supervisors cannot see all of the work from one place.
• Each zone has different hazards. Excavations, energized equipment, confined spaces and areas with heavy equipment each have their own rules about who can enter and for how long.

OSHA identifies four leading causes of death in construction: falls, being struck by an object, electrocution, and being caught in or between objects. In each case, the risk depends on where a worker is in relation to the hazard. Training and protective equipment are still the most important measures. Knowing where people are in real time adds another layer of protection on top of them.

What real-time tracking gives you

A real-time system answers four basic questions immediately, instead of after someone has checked the paperwork:

Question	With paper and radio	With real-time tracking
Who is on site?	Gate sign-in sheet, checked at the end of the shift	Current headcount by zone, contractor and shift
Who is in a hazardous area?	What the supervisor remembers	Alerts when someone enters or leaves a defined area, and how long they stay
Does anyone need help?	Someone notices or calls on the radio	SOS button, fall detection and no-movement alerts, sent automatically to the right people
Has everyone evacuated?	Roll call at the muster point	Muster status within seconds, with the names of anyone not yet accounted for

The equipment needed for this is now practical and affordable. Each worker wears a badge that is handed out at the gate and returned at the end of the shift. GPS tracks location outdoors, and small Bluetooth beacons cover indoor or enclosed areas. The badge has an SOS button and can detect falls and lack of movement. The badges connect over LoRaWAN, a long-range, low-power wireless network. A few gateways can cover a large site, so there is no need to run cables or pay for a cellular plan for every device.

Plan who receives each alert

A common mistake is to set up alerts without deciding who will act on them. If a man-down alert appears on a screen in an empty site office, it does not help the worker.

Before the system goes live, the safety team should decide:

1. Who gets the alert first. This is usually the supervisor responsible for that zone.
2. What happens if nobody responds. After a set time, the alert should go to the site safety manager, and then to site management.
3. How the alert reaches people in the field. Workers outside rarely check email. Mobile push notifications, text messages and radio integration work better.
4. Who can change the rules. Zone boundaries, check-in intervals for lone workers and alert limits are decisions for the site's safety team. They should be able to change them as the project changes, without asking the software vendor.

The software should store these settings and apply them consistently across all zones and contractors. The safety team should decide what the settings are.

Other uses for the same data

Safety is usually the main reason a program adopts worker tracking, but the same location data is useful for other tasks that take up administrative time:

• Contractor hours on site, based on actual badge data instead of timesheets.
• Access rules by zone. You can confirm that only qualified crews entered certain areas and that they did not stay longer than allowed.
• Equipment location. You get an alert when tracked equipment leaves its assigned zone.
• Records of drills and incidents. The system logs where each person was, when they moved and how long the evacuation took. Each record is linked to a badge ID and timestamp, which is much easier to defend in an audit than a folder of paper forms.

Examples from current deployments

Senzary's WorkerIQ is used this way today. At ENI's Dos Bocas facility in Mexico, 160 badges cover 350 employees and contractors on every shift. The system provides real-time location, H₂S exposure tracking and evacuation mustering, and it replaced spreadsheets and radio-based monitoring. On construction programs, WorkerIQ tracks workers, vehicles and hazards across active work zones covering 125 miles, including headcount, time on site, crew rotation and alerts when equipment leaves its zone.

WorkerIQ does not replace a site's access control system. Most sites keep their existing badges for doors and turnstiles and use WorkerIQ to track where people are once they are inside and to manage emergencies.

How to get started

You do not need to cover the whole program at once. Projects that go well usually start small:

1. Choose the zone or activity with the highest risk, for example a deep excavation, confined-space work or a night shift with lone workers.
2. Decide the muster points and who receives each alert before the equipment arrives.
3. Run an evacuation drill in the first two weeks and compare the automatic muster report with a manual roll call.
4. Add more zones once supervisors are comfortable with the system.

Next steps

You can read more about how WorkerIQ handles mustering, lone-worker check-ins and gas exposure. If you would like to discuss a pilot for one of your sites, you can book a call with our team.