Heat Stress and Traffic Controllers: Summer Safety on the Road

Heat stress is one of the most predictable risks for traffic controllers. They stand on dark bitumen in full sun, absorbing heat from the road and passing vehicles for hours without shade. Managing it means planning the shift, rotating and relieving controllers, providing shade and water, and knowing the warning signs of heat illness before they become an emergency.

This guide covers why road crews are especially exposed, how to recognise heat illness, and a practical summer plan for operators, supervisors and controllers. It is general information, not medical or safety advice. In an emergency, call 000.

Why traffic controllers are at high risk of heat stress

Most outdoor workers deal with heat. Traffic controllers have a particular combination that makes it worse:

• Radiant heat from the road. Asphalt absorbs sunlight and radiates heat back up, so the air at body height on a road can feel much hotter than the forecast.
• Heat from traffic. Engines and exhausts add heat, especially in slow queues at stop/slow points.
• Little or no shade. Controller positions are chosen for visibility, which usually means open ground.
• Limited ability to leave. A controller cannot walk off the bat when they feel unwell without stopping traffic or arranging relief.
• Clothing. Long-sleeve hi-vis protects against UV but holds heat.
• Standing still. Long periods standing in one spot, sometimes after early starts and long drives.
• Working alone. Pedestrian or side-road controllers may be out of sight of the rest of the crew.

Fatigue makes all of this worse. A worker who slept badly after a late finish is more likely to struggle in the heat, which is why heat and fatigue management in traffic control should be planned together.

Warning signs of heat illness

Heat illness ranges from mild to life-threatening and can progress quickly. Everyone on the crew should know these signs and what to do. This table is a general guide; follow first aid training and medical advice.

Controls that work: following the hierarchy

Heat is a WHS hazard like any other, so the controls follow the hierarchy: eliminate or reduce exposure first, then engineering and administrative controls, and PPE last. Safe Work Australia and the state regulators publish guidance on working in heat; start with Safe Work Australia and check your own regulator, such as WorkSafe Queensland, where summers are long and humid.

Reduce exposure

• Schedule around the heat. Where permits and road occupancy conditions allow, move works to early mornings or nights. This needs to be planned with the client and the approval authority, sometimes weeks ahead.
• Use devices instead of people where the plan allows. Portable traffic signals or other approved devices can remove a controller from the hottest position, but only if the traffic guidance scheme provides for them.
• Shorten exposure. Split long tasks so no one stands in one hot position for the whole shift.

Shade and cooling on site

• Shade umbrellas or small structures at controller positions, secured against wind and truck draught, placed so they do not block sight lines.
• A shaded rest area, which may be the air-conditioned ute cab, away from the traffic.
• Cool water in insulated containers within reach of every position, not just at the ute.
• Cooling towels or neck wraps, if the crew finds them useful.

Relief and rotation

This is the control most often missed, because it costs labour. On hot days, the crew needs enough people to relieve controllers regularly. Two controllers running stop/slow with no relief cannot take proper breaks. Build extra relief into the quote and roster when the forecast is hot, and agree the rotation at the briefing rather than leaving it to "when traffic eases".

Acclimatisation

People new to the job, returning from leave, or coming from cooler work are more vulnerable in the first days of hot weather. Give them lighter or shorter exposure at first, pair them with an experienced controller, and check on them more often.

PPE and clothing

• Lightweight, breathable hi-vis that still meets the requirements for the job
• Broad-brim hat or hard hat brim and neck flap, as the site allows
• Sunscreen, reapplied through the day
• Safety sunglasses suitable for the conditions
• Sweat-wicking layers under hi-vis

PPE protects against UV and helps a little with heat, but it does not replace relief, shade and water.

Planning for heat in quotes and rosters

Heat controls cost money, so they have to be planned before the job is won, not argued about on the day.

• Quote for relief. If a summer job needs an extra controller to rotate positions, say so in the quote and explain why. Clients generally accept a clear safety reason given up front far more readily than a surprise on the invoice.
• Talk to the client about timing. A builder who wants a 10 am start in January may be happy to start at 6 am if asked. Where the road occupancy or council permit fixes the hours, raise heat early so an earlier window can be requested.
• Roster with heat in mind. Avoid putting a controller who has just come off a run of night shifts onto an exposed afternoon shift in a heatwave. Fatigue and heat compound each other.
• Spread the hard positions. If one site has a long, unshaded stop/slow position, rotate who gets it across the week rather than giving it to the same person every day.
• Have a stop-work trigger. Decide in advance who can pause work when conditions become unsafe, and make sure crews know they will be backed up when they raise it.

Humidity, wind and the north

Air temperature alone does not tell you how hard the heat will be on the body. High humidity stops sweat from evaporating, so a humid 32 degrees in the tropics can be harder going than a dry, breezy day that is hotter on paper. Crews working in Queensland, the Northern Territory and northern Western Australia face long hot seasons with high humidity, and need heat planning for much of the year, not just a few weeks in January.

Building heat into your SWMS and pre-start

Heat should not be a surprise on the day. Name it as a hazard in the SWMS for traffic control, with the controls you will actually use and who is responsible for them. Then make it part of the daily routine:

• Check the forecast the day before and flag hot shifts to the allocator and supervisor.
• Add a heat question to the traffic control pre-start checklist on hot days: water on site, shade available, relief planned, everyone feeling well.
• Agree at the briefing who watches for heat symptoms and how a controller asks for relief.
• For anyone working alone or out of sight, set regular check-ins, and follow up immediately if one is missed.

Summer heat checklist for traffic control crews

Print this and keep it in the ute from November to March, or longer in the north.

Before the shift (office and allocator)

• Forecast checked and hot shifts flagged
• Crew size includes relief for regular breaks
• Start time moved earlier where permits allow
• Newer or returning workers paired with experienced controllers
• Shade umbrellas, water containers and ice loaded

At the briefing (supervisor)

• Heat signs and first aid reminded
• Rotation and relief times agreed
• Check-in plan for lone or remote positions
• Location of the nearest shaded rest area confirmed
• Site address and access point known for an ambulance

During the shift (everyone)

• Drink water regularly, before feeling thirsty
• Reapply sunscreen
• Watch your crewmates, not just yourself
• Ask for relief early rather than late
• Report symptoms immediately

What to do when a controller is affected

1. Relieve them from their post safely. Hold traffic if needed; the plan can wait.
2. Move them to shade or the air-conditioned ute.
3. Remove excess clothing, cool them with water and airflow, and give sips of water if they are alert.
4. If they are confused, collapse or are not improving, call 000.
5. Stay with them. Never send someone unwell to drive themselves home.
6. Report it, record it, and review the controls for the rest of the shift and the next day.

Heat sits alongside vehicles, fatigue and public abuse as one of the recurring hazards covered in our traffic controller safety guide.

Next steps

Get your heat plan into the SWMS and the pre-start before summer starts, and price relief into hot-weather jobs. If you run a traffic control company, TrafWise puts SWMS sign-off, pre-starts and lone-worker check-ins in the crew app, so heat controls are confirmed on every shift.