Highway Projects - Common Health & Safety Hazards, Risks and their Mitigation Measures during Design and Construction Phases

Hazard identification and risk assessment are both a legal requirement and a critical step for ensuring safe delivery of highway projects. Wherever possible, hazards should be eliminated at source, and residual risks must be controlled before they can cause harm. Effective risk management also leads to significant cost and time savings by preventing accidents, delays, and rework.

Designers have a duty to consider risks not only during construction, but also throughout the asset’s future maintenance, operation, and eventual demolition. They are responsible for recording and communicating risk-related information through drawings, specifications, and the Design Risk Register, enabling safe planning at every stage.

Construction teams are responsible for implementing safe systems of work, including compliance with method statements, permits-to-work, and control measures. They must also provide training, personal protective equipment (PPE), and competent supervision. Regular site inspections, toolbox talks, and enforcement of safety rules form part of their duties. Additionally, they are required to report near-misses, investigate incidents, and update control measures to ensure continuous improvement.

In the following a summary of the key health and safety hazards and risks in highway projects has been presented, together with potential mitigation measures during both the design and construction phases.

1. Unidentified Underground Services

Risks:

• Striking buried utilities during excavation.

• Service disruption, electrocution, gas explosion, or flooding.

• Project delays and legal liabilities.

 Potential Mitigation Measures at Design Stage:

• Commission comprehensive utility surveys (e.g., Ground Penetrating Radar, EML scanning).

• Consult statutory undertakers’ asset records.

• Include as-built utility drawings in the design pack.

• Provide trial pits in design phase where uncertainty exists.

• Incorporate safe working distances and protective measures in method statements.

 Potential Mitigation/Control Measures During Construction Phase:

•  Pre-excavation scanning with GPR and cable locators.

• Use permit-to-dig system with sign-off.

• Hand-dig trial holes before machine excavation.

• Mark utilities on ground and keep exclusion zones.

• Coordinate with utility owners for isolation where possible.

 2. Discovery of Asbestos-Containing Materials (ACM)

 Risks:

•  Inhalation of asbestos fibers leading to long-term health issues.

• Project stoppage due to regulatory compliance needs.

Potential Mitigation Measures at Design Stage:

• Conduct asbestos surveys for any structures or pavements that may pre-date asbestos bans.

• Specify in tender documents that ACM removal requires licensed contractors.

• Prepare an asbestos management plan and location register.

• Design for possible alternative methods if ACM is discovered mid-project.

 Potential Mitigation/Control Measures During Construction Phase:

•  Stop work immediately and isolate area.

• Confirm ACM presence via sampling.

• Use licensed asbestos removal contractors.

• Implement controlled wet removal to prevent fibre release.

• PPE: disposable overalls and P3 respirators. 

3. Discovery of Hazardous Materials

Risks:

•  Exposure to toxic substances (e.g., hydrocarbons, heavy metals).

• Environmental contamination.

• Regulatory enforcement.

 Potential Mitigation Measures at Design Stage:

•  Undertake Phase 1 & Phase 2 Environmental Site Assessments.

• Include contingency provisions in project budget and schedule.

• Design containment, encapsulation, or safe removal plans.

• Liaise with environmental agencies early.

 Potential Mitigation/Control Measures During Construction Phase:

•  Stop work, cordon off area.

• Engage environmental specialist to classify waste.

• Use bunded containment for spills.

• Provide PPE (chemical-resistant gloves, suits, respirators).

• Arrange licensed disposal.

 4. Discovery of Unknown Protected Species

 Risks:

•  Breach of wildlife protection laws.

• Project delays awaiting relocation or Potential Mitigation Measures Measures permits.

 Potential Mitigation Measures at Design Stage:

•  Commission ecological surveys (breeding birds, bats, badgers, reptiles, amphibians).

• Build potential mitigation measures into design (wildlife underpasses, timing restrictions).

• Obtain necessary wildlife licenses in advance.

• Plan works to avoid breeding/nesting seasons.

 Potential Mitigation/Control Measures During Construction Phase:

•  Halt work, contact ecologist.

• Implement temporary exclusion zones.

• Relocate species under licence.

• Adjust work programme to avoid sensitive breeding periods.

 5. Unexpected Ordnance

 Risks:

•  Injury or death from unexploded ordnance (UXO).

• Work stoppage and legal implications.

 Potential Mitigation Measures at Design Stage:

•  Conduct historical desk study for previous military activity.

• Engage UXO risk assessment specialists.

• Include UXO clearance procedures in pre-construction phase plan.

• Allow for stand-off zones in design.

 Potential Mitigation/Control Measures During Construction Phase:

•  Stop work, evacuate area.

• Call UXO specialists; follow exclusion distances.

• Train workforce in UXO recognition.

• Maintain no-dig policy in suspected areas until cleared.

 6. Dust, Noise, and Vibration

Risks:

• Health impacts to workforce and public.

• Nuisance complaints, regulatory fines.

 Potential Mitigation Measures at Design Stage:

•  Include dust suppression and noise barriers in design.

• Specify low-vibration equipment and methods.

• Position haul routes and noisy works away from sensitive receptors.

• Set performance limits in contract specifications.

Potential Mitigation/Control Measures During Construction Phase:

• Water suppression for dust.

• Noise barriers near receptors.

• Use low-vibration equipment.

• Schedule noisy works at acceptable hours.

• Provide hearing protection.

 7. Falling Objects

 Risks:

•  Injury to workers or public from dropped tools or materials.

 Potential Mitigation Measures at Design Stage:

•  Design to minimize working at height where possible.

• Incorporate edge protection and debris netting in temporary works designs.

• Ensure lifting plans account for safe load securing.

• Provide exclusion zones in layout. 

Potential Mitigation/Control Measures During Construction Phase: 

• Install debris netting and toe boards on scaffolds.

• Use tool lanyards at height.

• Exclude personnel below lifting zones.

• Maintain controlled load lifting and lowering. 

8. Confined Spaces

Risks: 

• Asphyxiation, toxic gas exposure, restricted escape. 

Potential Mitigation Measures at Design Stage: 

• Identify and record all confined spaces (manholes, culverts, chambers).

• Design for elimination of confined space entry if possible (e.g., remote inspection ports).

• Include rescue provisions in method statements. 

Potential Mitigation/Control Measures During Construction Phase:

•  Permit-to-work system with air quality monitoring.

• Forced ventilation in confined areas.

• Trained rescue team with retrieval equipment on standby.

• Continuous gas detection. 

9. Working Near Live Traffic 

Risks: 

• Vehicle collisions with workers or plant. 

Potential Mitigation Measures at Design Stage: 

• Design for offline construction where possible.

• Prepare traffic management plans with segregated zones.

• Include safe crossing points and temporary barriers.

• Stipulate reduced speed limits in work zones. 

Potential Mitigation/Control Measures During Construction Phase: 

• Implement traffic management plan (cones, signs, temporary barriers).

• Use high-visibility PPE.

• Employ traffic marshals and crash cushions.

• Night works only with adequate lighting. 

10. Working in Close Proximity to Live Overhead Services 

Risks: 

• Electrocution from contact with power lines.

• Service outages.

 Potential Mitigation Measures at Design Stage:

•  Identify all overhead lines via utility surveys.

• Design to avoid proximity or specify safe clearance distances.

• If unavoidable, incorporate protective barriers or isolation arrangements.

• Include warning signage and exclusion zones in design. 

Potential Mitigation/Control Measures During Construction Phase: 

• Maintain minimum approach distances.

• Use insulated plant and spotters.

• Where possible, request line isolation from utility provider.

• Warning signage and physical barriers. 

11. Working Near to Deep Water 

Risks: 

• Drowning, vehicle/machinery submersion. 

Potential Mitigation Measures at Design Stage: 

• Avoid siting works directly adjacent to water where possible.

• Include barriers, guardrails, and designated safe access points in design.

• Plan for rescue equipment and training in construction phase. 

Potential Mitigation/Control Measures During Construction Phase: 

• Install guardrails or barriers along edges.

• Provide life rings and rescue poles.

• Train workers in water rescue and lifejacket use.

• No lone working near water.

 12. High Embankments 

Risks:

•  Falls from height, slope instability, landslides. 

Potential Mitigation Measures at Design Stage:

• Conduct geotechnical stability analysis.

• Include retaining structures, berms, or safe batter slopes.

• Plan for staged construction to reduce risk of collapse.

• Include fall prevention measures in temporary works. 

Potential Mitigation/Control Measures During Construction Phase: 

• Install edge protection and slope stability monitoring.

• Control access to crest edges.

• Avoid overloading slope tops.

• Use MEWPs or scaffolds for slope works. 

13. Deep Excavation 

Risks:

•  Collapse of excavation walls, entrapment, falls. 

Potential Mitigation Measures at Design Stage: 

• Specify shoring, trench boxes, or slope angles in design.

• Avoid deep excavation by using alternative methods (e.g., piling).

• Conduct groundwater control and dewatering planning. 

Potential Mitigation/Control Measures During Construction Phase: 

• Benching, battering, or trench boxes to prevent collapse.

• Edge protection and ladder access.

• Dewatering systems for wet ground.

• Daily excavation inspections.

 14. Contaminated Ground

Risks:

•  Health hazards to workers, spread of contamination. 

Potential Mitigation Measures at Design Stage: 

• Identify contamination via intrusive investigation.

• Include remediation strategy in design.

• Select materials and methods resistant to contaminants.

• Segregate clean and contaminated spoil handling plans. 

Potential Mitigation/Control Measures During Construction Phase: 

• Segregate and store contaminated spoil.

• Use sealed haul routes.

• PPE for all personnel handling material.

• Avoid cross-contamination with clean areas.

 15. In-situ Concreting 

Risks: 

• Burns from wet cement, formwork collapse, heat stress.

 Potential Mitigation Measures at Design Stage: 

• Design formwork for stability and safe access.

• Specify mechanical handling for heavy pours.

• Provide curing methods that reduce manual handling near hazardous edges.

• Include safe washout areas in site layout. 

Potential Mitigation/Control Measures During Construction Phase: 

• Use stable, engineered formwork with regular inspections.

• PPE: gloves, goggles, waterproof clothing for cement contact.

• Safe access to pour areas.

• Designated washout areas. 

16. Vehicles on the road hitting deck and/or piers of overhead bridge 

Risks: 

• Vehicle impact on piers due to loss of vehicle control.

• Vehicle impact on bridge deck soffit

• Structural damage to bridge structure

• Risk to road users from the accident or from debris falling after impact

• Long-term operational disruption 

Potential Mitigation Measures at Design Stage: 

• Location of piers outside traffic lanes.

• Provision of adequate vertical clearance in compliance with DMRB

• Design to withstand accidental impact loads as per EN 1991-1-7

• Provision of VRS to protect bridge pier

• Provision of visibility of bridge as per DMRB

• Advance warning signs showing headroom clearance/height restriction boards 

Potential Mitigation/Control Measures During Construction Phase:

•  Traffic Management including full or lane closures with physical barriers around exposed piers

• Implementing speed reduction zones with enforcement measures

• Use of vehicle-activated signs or use of road diversion.

17. Working at Height

 Risks:

• Falls from scaffolds, formwork, bridges, retaining walls, lighting poles.

• Falling materials/tools injuring others below. 

Potential Mitigation Measures during Design Phase: 

• Minimize work at height by prefabrication at ground level where possible.

• Design safe access routes, guardrails, permanent anchor points. 

Potential Mitigation/Control Measures during Construction Phase: 

• Use proper scaffolding, mobile elevated platforms (MEWPs), and fall arrest systems.

• Implement permit-to-work system for height activities.

• Train workers in safe use of ladders and harnesses. 

18. Moving Plants and Vehicles 

Risks: 

• Struck-by accidents with dumpers, rollers, pavers, or delivery trucks.

• Vehicle overturns on uneven ground. 

Potential Mitigation Measures during Design Phase: 

• Plan for segregated haul roads and pedestrian walkways.

• Provide adequate space in design for vehicle movement/turning radii. 

Potential Mitigation/Control Measures during Construction Phase: 

• Enforce traffic management plans (signage, barriers, flagmen).

• Install reverse alarms, cameras, and flashing beacons.

• Mandatory PPE (hi-vis clothing, helmets, boots). 

19. Noise, Dust, and Vibration

Risks: 

• Hearing damage, respiratory issues, nuisance to nearby communities.

• Vibration damage to nearby structures. 

Potential Mitigation Measures during Design Phase: 

• Select low-noise equipment specifications.

• Optimize alignment to minimize community impact. 

Potential Mitigation/Control Measures during Construction Phase: 

• Use dust suppression (water spraying, covering trucks).

• Provide hearing protection, dust masks/respirators.

• Monitor vibration levels; limit night-time work near residential zones. 

20. Electrical Hazards 

Risks: 

• Electrocution from overhead lines or temporary site power.

• Fire due to faulty equipment.

Potential Mitigation Measures during Design Phase: 

• Route utilities carefully to avoid clashes.

• Specify residual current devices (RCDs) in temporary installations.

Potential Mitigation/Control Measures during Construction Phase: 

• Survey and mark underground/overhead services.

• Lockout–tagout procedures for electrical systems.

• Regular inspection of cables, generators, lighting towers.

21. Manual Handling

Risks:

• Musculoskeletal injuries (back strain, sprains). 

Potential Mitigation Measures during Design Phase:

•  Reduce manual lifting by designing for mechanized handling.

• Specify modular, lighter components where possible. 

Potential Mitigation/Control Measures during Construction Phase: 

• Provide lifting aids (hoists, cranes, dollies).

• Train workers in correct lifting techniques.

• Rotate tasks to avoid fatigue. 

22. Heat Stress and Dehydration 

Risks: 

• Heatstroke, fainting, dehydration, reduced concentration → accidents. 

Potential Mitigation Measures during Design Phase: 

• Plan work sequences to minimize peak heat exposure.

• Provide shelters and shaded rest areas. 

Potential Mitigation/Control Measures during Construction Phase: 

• Enforce hydration breaks and rest cycles.

• Provide cool drinking water and electrolyte solutions.

• Acclimatization programs for new workers. 

23. Falling Objects 

Risks: 

• Head injuries, fatalities, damage to property/equipment.

Potential Mitigation Measures during Design Phase: 

• Include toe boards, debris nets, protective canopies. 

Potential Mitigation/Control Measures during Construction Phase: 

• Enforce exclusion zones beneath lifting operations.

• Secure tools and materials at height.

• Mandatory helmets for all site staff. 

24. Confined Space 

Risks: 

• Asphyxiation, toxic gases, entrapment, difficulty in rescue. 

Potential Mitigation Measures during Design Phase: 

• Provide adequate access/egress and ventilation points.

• Avoid confined space requirements where possible. 

Potential Mitigation/Control Measures during Construction Phase: 

• Gas testing and ventilation prior to entry.

• Permit-to-work and rescue plans in place.

• Continuous atmospheric monitoring.

 25. Fire Risks 

Risks: 

• Fire during welding, fuel storage, hot works; spread to nearby vegetation. 

Potential Mitigation Measures during Design Phase: 

• Allocate safe zones for fuel and material storage.

• Specify fire-resistant materials where possible. 

Potential Mitigation/Control Measures during Construction Phase: 

• Hot work permits, fire extinguishers on site.

• Designated smoking areas.

• Training in fire drills and emergency evacuation. 

26. Handling Chemicals and Asphalt 

Risks: 

• Burns from hot bitumen, skin/eye irritation from solvents, inhalation of fumes. 

Potential Mitigation Measures during Design Phase: 

• Select less hazardous materials where alternatives exist.

• Provide adequate storage facilities and drainage to prevent contamination.

 Potential Mitigation/Control Measures during Construction Phase:

•  Use PPE (heat-resistant gloves, goggles, masks).

• Train workers on safe handling and spill response.

• Enforce proper storage/labeling of hazardous materials. 

These hazards require comprehensive risk assessments and the implementation of robust health and safety policies to ensure worker safety and compliance with legal standards. Regular training, monitoring, and updating safety measures are also crucial to adapt to changing conditions and emerging risks.