A well-designed and maintained site will make workplace vehicle accidents less likely.

This section is useful for all extractives sites when designing roads and other vehicle operating areas.

For mining operations and A-grade quarrying and A-grade alluvial mining operations, this section will assist with the drafting of the principal hazard management plan (PHMP) for roads and other vehicle operating areas.

To determine what hazards may be present, consider what vehicle activities will take place on a road or other vehicle operating areas.

Hazards associated with roads and other vehicle operating areas include:

• vehicles rolling over or going over edges
• trays flipping over on articulated dump trucks
• ground failure onto or below vehicles
• collisions between vehicles and between vehicles and pedestrians
• uncontrolled movement of vehicles
• vehicles coming into contact with overhead power lines or other structures.

On this page

• 8.1 Appraisal of roads and other vehicle operating areas
• 8.2 PHMP for roads and other vehicle operating areas
• 8.3 Design and layout of roads
• 8.4 Traffic management plan

8.1 Appraisal of roads and other vehicle operating areas

For mining operations, A-grade quarries and A-grade alluvial mining operations, the responsible person must carry out an appraisal of the operation to identify principal hazards.

To determine if roads and other vehicle operating areas are a principal hazard, the responsible person should consider:

• how a road or other vehicle operating area could fail (for example, collapse or slips) and the likely consequences of a failure
• the type of vehicles using the road or other vehicle operating areas
• the activities that take place and the consequence of any interactions between vehicles and pedestrians, structures or other vehicles, for example:
  • vehicles carrying passengers
  • light and heavy vehicle interactions
  • travelling under overhead power lines
  • loading over a cab where a driver may be present
• how a vehicle may lose control and the likely consequences (for example, driver falling asleep, mechanical failure or tip over)
• the hazards on the road or other vehicle operating area (for example, sharp corners, steep gradients or large drop-offs)
• any other hazard involving vehicles.

The responsible person should consult a competent person for technical input and advice as required when considering whether a principal hazard exists.

A risk assessment must be completed for the roads and other vehicle operating areas principal hazard. A description of how you will conduct the risk assessment, as well as the results of any risk assessments completed, must be included in the roads and other vehicle operating areas PHMP.

8.2 PHMP for roads and other vehicle operating areas

Where an appraisal has identified a principal hazard, the responsible person must make sure there is a PHMP.

What the responsible person must include in the PHMP

The PHMP must contain the general PHMP requirements listed in Section 2.6 of these guidelines and Regulation 68 of the MOQO Regulations. Before drafting the PHMP, the responsible person must take into account:

• the characteristics of the vehicles and other mobile plant to be used
• the conditions of the road or other vehicle operating areas at the operation (including time of day, visibility, temperature and the effects of the weather).

For a full list of requirements for roads and other vehicles, see Regulation 80 of the MOQO Regulations.

The responsible person should develop the PHMP in the context of the entire HSMS. This will help identify gaps and overlaps when putting control measures in place for roads and other vehicles.

There will likely be some similarities between this PHMP and your mechanical engineering control plan.

8.3 Design and layout of roads

Every site is different and likely to present different hazards and risks. However, a well-designed and maintained site with suitable separation of vehicles and people will make vehicle accidents less likely.

You must eliminate risks so far as is reasonably practicable. If the risks cannot be eliminated, you must minimise them, so far as is reasonably practicable. The risk of pedestrians and vehicles interacting should be eliminated and, if not reasonably practicable, minimised. The most effective way to achieve this is to provide separate pedestrian and vehicle routes and, where practicable, keep light and heavy vehicles separate.

The life of the operation and future extraction designs should be considered when determining durability, size and maintainability of the roads. Locating roads in places that will not be impacted by future activity avoids rebuilding costs.

Terrain and geotechnical considerations

When designing and establishing roads, consider the terrain and geotechnical issues. They will affect the type of operation, the mobile plant used, and where infrastructure can be located.

With a geotechnical report and advice from a competent person, you can determine the best locations for roads, extractions and processing areas.

Operational parameters

Before construction, consider how operating parameters affect the design, layout, materials and maintenance requirements of the road. These parameters include:

• the vehicle manufacturer’s recommendations for the use of each vehicle
• the characteristics of the vehicle and the type of load that will use the road
• expected traffic volume
• operating hours
• setting vehicle operating speed limits in conjunction with windrow design
• gradients (including super-elevation)
• road camber
• materials available for road construction and maintenance
• typical weather conditions.

Autonomous mining equipment

Careful planning is needed when using autonomous equipment, particularly the interaction between machines, people and the environment.

For more information, see the ISO 17757 Earth-moving machinery and mining standard. The following guidelines from Global Mining Guidelines Group may also be useful Guideline for the Implementation of Autonomous Systems in Mining – Version 2 – Global Mining Guidelines Group(external link)

Design of roads

Design roads that are:

• adequate for the number, type and size of the largest vehicles that may use them
• suitable for various driver positions including height and cab position (for example, right, left or centre position).

Roads should:

• be constructed with suitable material to provide firm surfaces, adequate drainage and safe profiles to allow for safe vehicle movements
• be clearly signposted including speed limits and radio telephone call point areas
• where appropriate, have edge protection and road markings (for example, sealed roads) or delineators showing the right of way
• have speed limits and speed control measures specific to site conditions and the types of vehicles using the route
• have adequate protection against rockfalls (for example, a catch ditch, catch bench or suitable barrier)
• be clearly delineated when it is dark, by using lighting, reflective marker pegs or similar devices, or have suitable access restrictions to hazards (for example, ponds or other water-filled hazards or steep drop-offs)
• allow for back break of the bench crest during the life of the road, as this may cause risks to stability near the crest. The amount of back break will depend on the geotechnical characteristics of the bench
• use one-way systems and turning points to minimise the need for reversing
• accommodate the turning circles of vehicles likely to use the road.

Also consider:

• access to the site including weight restrictions on bridges and narrow roads
• height limitations for traversing under overhead structures
• where distribution points will be (for example, processing areas, weighbridge locations, load covering areas, loading areas, points of sale to the public)
• the impact of land adjacent to the road (for example seepage from adjacent wetlands).

Where reasonably practicable, haul road design should avoid:

• office facilities and parking areas for light vehicles
• unstable areas
• hazards such as excavations, ponds, structures, fuel or chemical storage areas, underground working or voids, and overhead power lines
• steep gradients and tight bends
• one-lane two-way routes.

You may need to consult a specialist traffic engineer for complex traffic flows, especially at sites with large processing operations.

Road widths

The width of a road should be based on the size of the largest vehicle in use. The larger the vehicle, the more clearance is needed.

Each lane of travel should be at least 1.5 times the width of the widest vehicle or mobile plant that would normally use the road. For a two-lane road, the width should be at least three times the width of the largest vehicle. Provide extra room for drains, windrows or centre windrows. See Figure 17 for an example of this.

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If it is not reasonably practicable to have two-lane roads, provide adequate passing bays and turning points. One-lane roads and turning points are not recommended on haul roads.

It may be appropriate to use turning bays to allow vehicles to turn and drive forwards most of the time. Turning bays would ideally be a roundabout or a ‘banjo’ type, although ‘hammerhead’ and ‘stub’ arrangements may be acceptable, see Figure 18 for examples.

Where reasonably practicable, interactions between light and heavy vehicles should be eliminated. Do this by providing segregation of light vehicle on roads also used by off road dump trucks.

Where elimination is not reasonably practicable, minimise interactions between light and heavy vehicles using the following control measures:

1. Separation (different haul road).
2. Segregation (bund separation on the same haul road). See Figure 19.
3. Administrative control measures (for example, traffic lights or boom gates).

Consider the interactions of light and heavy vehicles when entering and leaving haul roads.

Bends on haul roads should be designed wider than the straight stretch to allow for the overhang of vehicles using it.

Switchbacks or other areas on haul roads requiring sharp curves should be designed to take into account the minimum turning radius of the haul trucks.

Road gradient

Important aspects of the steepness or grade of a roadway include:

• compatibility with the braking capabilities of the vehicles (with a factor of safety)
• compatibility with the performance capabilities of the vehicles
• effect on a vehicle’s stopping distance
• ability of a vehicle to operate safely in wet conditions
• speed around bends, which is affected by super-elevation.

DETERMINING THE GRADE OF A ROAD

The steepness of a road is normally expressed as a ratio which is determined by measuring the distance travelled along the road in relation to the vertical height change (see Figure 20). For example, a road with a 1m vertical change over a travelling distance of 10m has a ratio of 1:10.

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Information in vehicle manuals about braking and performance abilities on slopes may be provided as a grade percentage (see Figure 21).

The steepness of a road should be measured using surveying equipment. The grade should be determined over a portion of the road where the grade is constant. Where the steepness varies, the grades should be determined for different segments.

GRADE AND VEHICLE COMPATIBILITY

The grade of a road should be compatible with road conditions, the type of road surface and the vehicle capability. Vehicle brakes should be able to stop in the worst-case scenario without losing control of the vehicle. Particular attention should be paid when loads are moved downhill.

Different vehicles with different performance characteristics will use the roads. Roads should be designed to allow all vehicles to operate within their safety parameters. Road grades should never be designed to the maximum climbing or descending capacity of the vehicles that use them.

It is important vehicles are not overloaded as brake or retarder performances depend on the grade and the vehicle’s total weight (see Section 14.6).

GRADE SITUATIONS TO AVOID

Avoid road alignments that result in a sharp bend near the top of a grade. These are hard to see at night, when headlights tend to shine up into the darkness. If this cannot be avoided, the bend should be defined, for example, by using extended reflective markers.

Also avoid sharp bends near the bottom of a grade. Here, vehicles tend to pick up momentum, making it more difficult to maintain control around the bend. If you cannot avoid a sharp bend, a safe speed for descending the grade should be posted and adequate restraining measures such as large windrows or runaway provisions should be used.

SUPER-ELEVATION

Super-elevation is the banking of the road pavement at bends. It can assist vehicles to manoeuvre safely around corners. It allows the vehicle taking the corner to counteract forces towards the outside of the bend, by directing the vehicle’s weight towards the centre, or radius, of the bend. The amount of super-elevation on a bend is directly related to the radius of the corner and the desired vehicle speed through the corner.

Table 6 is a guide for providing the super-elevation necessary to reduce lateral forces. The maximum super-elevation should be regarded as 1:20.

Super-elevation is an important design consideration for switchbacks on haul roads as they typically have a small turn radius. On switchbacks, which have the centre of the bend located on the up-side of the road, a well-chosen superelevation rate prevents material being spilled from laden trucks and improves vehicle control.

As with changes in grade, transition into and out of super-elevated bends should be smooth so vehicles can be eased into corners. Super-elevation transition lengths depend on the cross-fall change and the design speeds. The larger the change in road alignment, the longer the transition should be. Transition lengths should be applied so that one-third is on the bend and two-thirds are on the tangents (see Figure 22). Table 7 outlines the recommended lengths.

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Sight distance

Sight distance is how far along the road a driver can see ahead of their vehicle (see Figure 23). Roads should be designed to give drivers a sufficient distance of clear vision ahead to avoid unexpected obstacles. At intersections, consider the windrow design to ensure good visibility. A basic rule of safe driving is that, at all times, a driver should be able to stop the vehicle within their sight distance. If a driver sees a problem, such as a boulder on the road or a stalled vehicle, they should be able to stop in time to avoid it.

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Roads should be designed with viewing distances and alignments. This ensures that a vehicle rounding a bend, cresting a hill, descending a grade, or approaching a junction can stop in time to avoid an obstacle or another vehicle pulling onto the road (see Figure 24). Consider the seated height of a driver in different vehicles.

SIGHT DISTANCE IN BAD WEATHER OR AFTER DARK

Sight distance can be reduced during inclement weather such as rain, snow or fog. In these conditions, drivers should slow down enough to stop within the available sight distance. Effective headlights, flashing beacons and spotlights improve the ability to see and be seen.

When driving after dark, sight distance can be defined by the distance illuminated by the vehicle’s headlights. Drivers should reduce their speed so they can bring the vehicle to a stop within the illuminated distance. This distance will vary with the type of headlight. To be most effective, headlights should be kept properly aimed and clean. Speed should be reduced at night because drivers typically have reduced depth perception, peripheral vision and reaction times.

There is often little contrast in brightness between the background and other objects at an extractives site, especially in snow. Roadside reflectors should be installed to help define the roadway and intersections. Vehicles used at night should have lights that can be seen from the side of the vehicle, as well as the front and rear.

SIGHT DISTANCE AT INTERSECTIONS

Sight distance is important at intersections. A driver should be able to see oncoming vehicles far enough away to safely turn onto or cross the road. Ideally, drivers should be able to pull onto the road, or cross the road, without requiring approaching vehicles to slow down. The main factors in the safe sight distance at intersections are the acceleration ability of the vehicles pulling onto the road and the speed of the oncoming traffic.

Because of the limited acceleration ability of trucks, especially when laden, ample sight distance should be provided. The higher the speed on the road, the longer the sight distance should be.

Avoid locating intersections near hill crests or sharp curves. In these situations, sight distance will be limited. Intersections should be kept as flat as possible and sight distance should be considered in all directions.

In laying out intersections, consider the effect of the large blind spot to the right or left side of haulage trucks (depending on the position of the driver’s seat). Intersections where trucks need to stop or give way to other vehicles should be angled to optimise the driver’s ability to see vehicles coming from both the right and left sides (see Figures 25 and 26).

For roads used by haulage trucks, avoid roads that intersect at an angle of less than 90° on the opposite side of the driver. Alternatively compensating measures should be taken (for example, convex mirrors, reduced speed zones, communication systems or on-board cameras).

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When using ‘give way’ controls at an intersection, there should be visibility clearance of 1.2 times the priority road speed limit, 9m back from the intersection (see Figure 27). Where this is not possible, a ‘stop’ control should be used that requires vehicles to come to a complete stop (see Figure 28).

Drainage

Having good drainage systems will:

• prolong the life of the road
• reduce maintenance costs on roads and vehicles
• minimise downtime
• minimise adverse health effects on drivers
• improve tyre life.

Drainage is generally provided using the following:

CROSS FALL (OR CROSS SLOPE)

Surface drainage is designed to cause the water to leave the road as shallow, non-erosive sheet flow in a way suited to the road material, slope and terrain. To promote drainage, either the road surface should be sloped from one side to the other, or the road should be crowned (or raised) in the centre.

Typical cross-falls for unpaved roads in New Zealand are 3.5% to 4% and 2% to 4% for paved roads. On haul roads, a cross-fall between 2% and 4% is preferred. Steeper crowns can increase tyre wear and metal fatigue in trucks. Cross-falls should not be carried around a bend. Instead, there should be a transition zone between the normal cross-fall road and the start of the super-elevation of the bend.

FREE-DRAINING ROAD MATERIALS

These allow water on the road surface to drain down and out.

ROADSIDE DITCHES

These collect drainage from the road surface and intercept runoff from adjacent hillsides.

CULVERTS

Culverts carry runoff under the road surface to a drainage course. They vary in size from 300mm concrete or corrugated metal pipes to large shapes 3m or more in diameter. The inlets and outlets for the larger sections usually have concrete headwalls and wing walls to reduce erosion. The smaller pipes usually have bevelled end sections for the same reason.

Culverts should be buried deep enough to prevent them being crushed by vehicles passing over them. Manufacturers can provide information about suitable depth.

Unless the culverts lead to additional diversionary ditching, provide water run-outs to reduce the velocity to where the water is non-erosive. On shallow slopes (less than 10%) with limited water flows (<0.5m/s), this can be done with vegetated outflow areas. Energy dissipaters (riprap or tipped rock) may be required where flow rates are higher.

Provide and maintain good drainage to make sure low water levels in the road fill in areas of a naturally occurring high water table (for example, swamps or watercourses).

Temporary in-pit roads with high ground water levels can be improved by placing gravel or rockfill over the area, or by installing pumping wells to lower the water table. Pumping wells may be cost effective if they also reduce the water level in, and improves the stability of, the working area.

Make drainage features large enough, and space them apart so they can handle the greatest expected demands on them.

During or right after rain is a good time to check that drainage is working properly.

Road pavement

Surface and drain all roads adequately to make sure vehicles can be driven safely.

The materials that make up the road pavement and road base should provide:

• adequate traction
• support for vehicles without excessive sinking or rutting.

TRACTION

A road pavement of gravel or crushed stone is preferred. While some other materials provide better traction when dry, a gravel road pavement offers good traction in wet and dry conditions.

You may have to import gravel or crushed stone if it is not available on site. Alternatively, if all weather pavements are not practicable and roads become untrafficable due to weather or underfoot conditions, you should have procedures that outline when operations should stop and restart. For example, a Trigger Action Response Plan (TARP). You should base these procedures on technically sound risk assessments.

The forces required for accelerating, turning, or stopping vehicles are caused by the friction generated between the tyres and the road pavement. The amount of friction available varies with different road pavements and is indicated by a friction coefficient, which is a measure of how well the tyre grips the road pavement.

The friction coefficient indicates how much of the total weight of the vehicle can be generated as a force between the tyre and the road pavement. The higher this force, the better the grip on the road and the more control the driver has in climbing, steering and stopping.

Table 8 shows some typical friction coefficients for different road pavements. Notice the significant differences in values, varying from concrete (0.9) down to ice, which can be practically zero. The value of 0.9 for rubber tyres on concrete means 90% of the weight on a tyre is available as braking force (assuming the brake components themselves can provide this much braking force).

The different values show how important it is that drivers adjust their speed to suit the road conditions. All other factors being equal, it will take a longer distance to stop when traction is low. If the friction coefficient is reduced by half, the stopping distance is doubled once the brakes are applied. Friction values also affect steering ability. Reduce speed when traction is low.

The road pavement coefficients given in Table 8 are the maximum values for the indicated conditions. Maximum tyre grip occurs when the tyre is still rolling and just before the tyre would lockup and slide. Once a tyre locks up and goes into a skid, the available friction is reduced. This reduction can be as much as 50% under poor road conditions. This is why antilock brakes are so beneficial. They help prevent tyres from locking up, so the available friction remains high. Brakes stop the wheel, but it is the grip between tyre and road pavement that stops the vehicle.

SUPPORT

Rutting of a soft pavement can create a hazard by affecting a driver’s ability to control their vehicle and exposing them to rough or jarring conditions. Rutting occurs when tyres sink into the pavement because the road pavement does not offer adequate support. Fine-grained soils, even when well-compacted, may not support the tyre loads imposed by large haul trucks, especially in wet conditions.

To eliminate or minimise rutting, a road base material should have sufficient strength to support tyre loadings. A layer of gravel or crushed stone, for example, has higher bearing strength and will distribute the tyre loadings over a larger area. A layer of geotextile can help provide a road base with good support for tyre loadings. If a road base is not strong enough to support tyre loadings, the road will need a lot of maintenance to keep it in good condition.

Roadside edge protection

Edge protection helps protect drivers and others at risk if a vehicle leaves the road.

Provide adequate windrows or guardrails where there is a change of level, drop, pond or any other hazard.

Roadside windrows are a common safety feature along elevated roadways. Windrows help:

• the driver see the edge of a roadway
• give the driver a sense of contact if the vehicle makes contact with them
• restrain an out-of-control vehicle, allowing the driver to regain control and keep it from leaving the road
• keep a vehicle away from the edge of the roadway by a distance equal to at least the width of the windrow.

Windrows on roads should be of sufficient height and width, constructed with suitable material, and be steeper on the roadside.

EARTHEN WINDROWS

Windrows are often built of earthen material and need to be designed and constructed to a pre-determined standard to be effective. Their suitability depends on factors such as height, width (or thickness) and firmness.

In some cases, windrows that are half the wheel height of the largest vehicle may be too low to prevent certain vehicles from going off course. For example, an articulated dump truck travelling 30km/h may require a windrow at least 66% of its wheel height to be redirected back onto the intended route (see Figure 29). The shape and width of the windrow also plays a crucial role (see Figure 30).

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Windrows that are too low or have curved slopes can act as ramps, making them ineffective. Before installing or constructing windrows, consult a competent person for advice.

When designing windrows, consider:

• the type of vehicle, for example rigid or articulated
• the mass of the vehicle
• the operating speed of the vehicle
• the size of the tyres
• where the vehicle is required to operate
• the type of material available to build the bund.

Windrows can deteriorate due to weathering and should be regularly inspected and maintained to make sure they continue to be effective. This should be done as part of the manager’s daily site inspection.

CONSTRUCTING WINDROWS

One way for a windrow to provide restraint is by deflecting the tyre and redirecting the vehicle back onto the road. To do this, make the windrow material firm, and the inside slope as nearly vertical as possible (a slope greater than 40° is recommended). When cutting the inside slope to steepen the windrow, make sure enough material is initially placed so, once the windrow is acute, the base width is still adequate. Make the base width at least the width the windrow would have been if both its outside and inside slopes were at the material’s angle of repose. Maintain a full base width to serve the function of keeping vehicles back from the edge.

Windrows constructed of broken rock mixed with bonding materials will normally provide restraint due to the interlocking and frictional resistance of the rock pieces. If a windrow is too loose, it will provide little restraint, and the vehicle may plough straight through it. If a windrow is firm, but is not steep on the roadway side, the vehicle could ride up and over it.

A windrow can also impede the passage of a vehicle by a combination of the tyre sinking into and raising up as it climbs the windrow material. The vehicle may get bogged down as it ploughs through. To effectively impede a vehicle in this way, a windrow should generally be larger than axle height. In general, when finer materials are used, less effort is made to compact and shape a windrow, so the windrow should be larger to provide similar restraint.

If there is significant risk that mobile plant could breach windrows, consider having more substantial windrows. For example, the typical axle-height berms might not be enough to stop large and heavy vehicles. Windrows much larger than axle-height are required to completely stop a vehicle for all possible conditions of speed and impact. For vehicles under 85t, windrows should be constructed to a height three times the axle height. For vehicles over 85t, windrows should be constructed to a height four times their axle-height. This is based on a vehicle contacting the windrow at 48km/hr at a 30° angle of contact.

The amount of restraint offered by a windrow depends on the conditions under which the vehicle hits it. The greater the vehicle speed, or the more head-on the vehicle contacts the window, the larger the windrows have to be. Use larger than typical windrows in areas where it is reasonable to expect more adverse conditions, such as where vehicles would have more speed or would contact the windrow head-on. For example, where there is a curve at the bottom of a grade. In these cases, increase the windrow size or consider other provisions, such as runaway lanes or double windrows.

Make roads wide enough so windrows are constructed on a firm foundation that is level with the roadway (see Figure 31). If the road width is inadequate and a portion of the windrow extends over the hillside, the windrow will be more likely to give way when hit and offer little restraint.

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Leave gaps in the windrow or other drainage systems provided where necessary, to allow drainage of surface water (see Figure 32). Make sure any gaps are not wide enough for a vehicle to pass through. Design them so a vehicle’s wheel cannot be trapped at an angle leading away from the travelling direction.

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Boulder windrows

Sometimes a continuous row of boulders is used to form a windrow. When a vehicle hits a boulder windrow, the restraint comes from the frictional forces involved in sliding the boulder ahead of the vehicle.

Boulders cannot be placed right at the edge of the drop off because there has to be a distance available for the vehicle to push the boulders. This distance will depend on the size of the boulders and the size and speed of the vehicle.

For that reason, stone blocks or tyres placed individually along the edge of a road, which can be easily pushed out of the way by a vehicle or increase the risk of injury to the driver, are not suitable for windrows (see Figure 33).

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Blocks of stone or tyres may be used, provided you heap materials (such as scalpings) between the blocks or tyres so they can safely absorb the impact of a vehicle and will not be easily pushed (see Figure 34).

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Guardrails

When using guardrails instead of windrows, they should:

• clearly indicate the edge of the road
• give the driver a sensation of contact if they accidentally hit the guardrail
• deflect the vehicle back onto the road
• prevent the vehicle from driving over the edge.

Consult a qualified engineer with suitable experience to determine the adequate design and construction of guardrails.

Because of the large size and mass of haul trucks, guardrails generally need to be higher and stronger than those typically used on public roads.

Embed guardrails deep enough to provide adequate resistance. Guardrails should be strong enough to stop or deflect the vehicle back onto the roadway.

Installation and use should not exceed the manufacturer’s recommended limits in respect to vehicle type, size and weight.

Keep guardrails easy to see by adding reflective material. This helps drivers spot them at night and recognise them as edge barriers.

Control measures for runaway vehicles

Safety features should be incorporated into road design to control runaway vehicles. Typical edge-of-road windrows alone should not be relied on to stop a large haul truck. Other methods such as centre berms and escape lanes can bring a runaway vehicle to a safe stop and prevent a more serious outcome.

Centre berms are piles of loose granular material placed strategically along the centreline of the road (Figure 35). In the case of brake or retarder failure, the driver manoeuvres the vehicle in line with the berm, so the vehicle straddles the berm and is brought to a halt.

When installing centre berms, consider:

• the nature and size of the laden weight of the vehicle that might need to be driven onto or straddle the centre berm
• using material that provides sufficient drag on the vehicle
• positioning the centre berms so that vehicles have limited time to pick up speed
• allowing adequate space between berms so that the driver has time to position the vehicle.

When installing escape lanes, consider:

• the size and expected speed of a laden runaway vehicle that might enter the lane
• alignment of the lane and the road
• that the driver of the runaway vehicle should be able to steer it into the lane
• the size and length of the lane. The lane needs to be wide enough and long enough to allow vehicle access and time for it to slow and stop
• that the lane should be constructed of material that offers a high rolling resistance that will not compact (for example, loose gravel or crushed aggregate).

For examples, see Figures 36 and 37.

Parking areas

When establishing parking areas, consider:

• separating pedestrians, and light and heavy vehicles, including private vehicles (for example, workers’ cars)
• locating the parking area on flat ground if possible and avoid locations where buildings, such as offices, could be struck by vehicles
• using consistent design and layout
• using one-way systems to limit the need for reversing
• using stop blocks or spoon drains to prevent unintended vehicle movement
• having clear signs.

For more information see Section 14.5.

Tips or stockpiles

When establishing tips or stockpiles, think about the vehicle activities that will occur in these areas and set up control measures to manage the risks. For example:

• ensure sufficient room for vehicles to operate
• use one-way systems where possible
• manage stockpiles so they do not encroach on vehicle operating areas or restrict drivers’ lateral vision
• restrict access for light vehicles and pedestrians
• provide adequate lighting if operating at night.

For more information on tips and stockpiles, see Section 11.

Workshops and fixed plant areas

A vehicle collision with a pedestrian, machinery or another vehicle is much more likely in workshops and process plant areas due to the restricted vision around fixed plant and doorways. To reduce the risk of this occurring:

• provide specific parking areas
• restrict vehicle access as much as practicable
• have clearly marked pedestrian crossings and walkways
• install bollards or barriers to protect infrastructure close to roads
• set appropriate speed limits with clear signs
• locate workshops away from production areas and haul roads.

Ground instability hazards above and below roads

Road hazards can be created due to unstable material above or below the road. Rockfalls or slides of material onto the road could endanger passing vehicles.

Avoid constructing roads on unstable or weak ground (such as those constructed on fill areas) as they may not be strong enough to support the vehicles that use them. When building a road against a slope, plan for it to be wide enough to accommodate catch trenches or bunds that will protect workers from falling material.

Road design should account for the potential of slope failure due to water, slumping or erosion.

Pay attention to the stability of any area where water is seeping out of a slope – the presence of water tends to make slopes less stable. For more information on drainage and depressurisation and on slope hazards, see Section 6.7.

ROCKFALLS

Where roads are adjacent to any highwalls, slopes or tips containing large rocks, make sure vehicles are protected from potential rockfalls.

Rock slopes tend to become less stable over time due to factors such as weathering and the effects of water. Regularly check slopes for overhangs, open joints or other evidence of unstable rock. Unstable material should either be removed, supported, or the area isolated (for example, with catch bunds or rockfall fences) so drivers are not at risk of a potential rockfall.

Consider how high and how far out from the wall the structure must be if using catch bunds or rockfall fences. This will help prevent passing vehicles being exposed to the hazard by absorbing and dissipating the energy of the falling rock.

How far a piece of rock will fall from a wall depends mainly on the steepness of the wall and the presence and condition of any structures. With a vertical wall, a rockfall would tend to end up near the base of the wall. With a sloping wall, or a wall with benches that have a build-up of material on them, the falling material will tend to bounce and be propelled further out from the base of the wall.

Maintenance should include clearing slips or rockfalls that could reduce the catchment area if left to build up. For more information on ground support, see Section 6.8.

CUT AND FILL ROADS

Filled roads should be constructed in compacted, horizontal layers. When fill is placed on an existing slope, the layers should be tied in by first removing vegetation and cutting horizontal benches into the existing slope material. Any springs or seepage areas should be collected in a drain to prevent the fill becoming saturated. Repair eroded fill slopes before they become a risk to road users.

Watch for signs that the ground below the road may be unstable (for example, tension cracks or settling). Slopes may become unstable as they absorb rainfall, become eroded, or are loaded by the weight of heavy vehicles.

8.4 Traffic management plan

Regardless of the size of your site, you should produce a traffic management plan that identifies the risks associated with vehicle movements on site and how to control them.

Traffic management plans usually show vehicle routes, flow, access points, parking areas and other vehicle control areas such as assembly points.

The plan should include roads and other key features of your traffic management system. It will form part of your roads and other vehicle operating areas principal hazard management plan (PHMP) if you are a mining operation, A-grade quarry operation or an A-grade alluvial mining operation.

Update your traffic management plan to reflect changes at your site and communicate these changes to all workers and visitors, for example, during induction or toolbox talks, or at sign-in.

For more information on traffic management plans, see our guidance Managing work site traffic

Traffic signs and markings

Use signs (including delineators) and line markings for drivers and pedestrians, consistent with those used on public roads (where a suitable sign or marking exists). This is to ensure instructions are easily recognisable to drivers and pedestrians.

Keep signs clean to make sure they continue to be effective. Maintaining signs should form part of your road maintenance programme.

Use illuminated or reflective signs, markings or delineators where driving is likely to be carried out in the dark.

Use delineators suitable for the size of the largest vehicle using the road.

Consider taller delineators (road markers) in areas that receive snow to make sure they are always visible where snow can drift or where graders may otherwise bury them.

Signs could be used to inform drivers or pedestrians about the routes to use and how to behave safely (for example, whether they should use protective equipment, and how). See Figure 38.

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Warning signs to show hazards along the way could also be appropriate. See Figure 39.

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Speed limits

Speed limits should be established based on a risk assessment carried out by a competent person. The assessment should consider the layout and condition of the roads, and the capabilities of the vehicles using the roads.

For any given section of a road, the speed limit should be the speed at which, under normal conditions, sight distances are adequate, curves can be safely negotiated, and any downgrades can be travelled without exceeding the vehicle’s braking capabilities. Speed should be consistent with the width and smoothness of the road so the driver can drive safely with a reasonable level of comfort and control.

Speed limits should be set at a level that allows for changeable weather visibility conditions.

SPEED ON DOWNHILL SECTIONS

The speed limit posted on downhill sections should take into account the braking capabilities of the vehicles using the road.

On haul roads, speed limits should be reduced in advance of a downhill section to account for the lag time involved before retarders are engaged (if fitted). Consult the vehicle’s operator manual to determine braking capability and retarder lag time requirements.

It is common to have different speed limits for uphill or downhill travel. Signs recommending gear selection may be required.

SPEED AROUND A BEND

Speed limits around bends can only remain the same as at the straight sections of road where the super-elevation and radius has been designed to allow this to happen. Where this is not possible, reduce speed limits. Speed limits will need to be sign-posted accordingly.

Lighting

Lighting an extractives site is more difficult than lighting a public road because of the uneven surfaces and the deceptive effects of shadows. Provide adequate lighting to enable workers to move safely around places of work.

In addition to vehicle-mounted lights, lighting should be provided:

• around plant, services and buildings
• on pedestrian routes
• where loading and unloading takes place
• at tip points
• at water bodies where access is required, for example to pontoons and pumps
• where practical, such as at important instructional signs.

A vehicle’s lights should be sufficient to enable it to be driven safely. Additional lighting may be required for manoeuvres such as reversing, dumping, or at intersections.

Position lights so they do not dazzle the driver when they come around a corner or drive over a crest. When using diesel- or petrol-powered lighting systems, make sure they:

• are positioned safely (for example, off road lanes)
• will last the shift without needing to be refuelled
• form part of your maintenance schedule.

Maintaining control over roads and other vehicle operating areas

Regardless of whether your operation has a PHMP or not, you should have identified control measures and implemented them to make sure that what has been planned will be carried out.

Put a structured programme of inspections in place to check and verify that your control measures for roads and other traffic areas are maintained. These should be inspected regularly by a competent person, with the reports reviewed by a supervisor or manager.

There may be times when inspection by a competent person, external to your business, is needed.