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Information Circular 8758 

Design of Surface Mine Haulage Roads - A Manual 

By Walter W. Kaufman and James C. Ault 

UNITED STATES DEPARTMENT OF THE INTERIOR

Cecil D. Andrus, Secretary

BUREAU OF MINES 

WMC Resources Ltd have the expressed permission of the "National Institute for Occupational Safety and Health" to 

replicate and present this document in Full for use by its employee's.

This document was kindly supplied by the:

National Institute for Occupational Safety and Health 

Pittsburgh Research Laboratory Library 

P.O. Box 18070 

PITTSBURCH, PA 15236-0070 
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CONTENTS 

ABSTRACT .....................................................................................................................................................4

INTRODUCTION.............................................................................................................................................4

HAULAGE ROAD ALIGNMENT ..........................................................................................................................4

Stopping Distance--Grade and Brake Relationships .......................................................................................5

Sight Distance ............................................................................................................................................8

Vertical Alignment ......................................................................................................................................9

Maximum and Sustained Grades..............................................................................................................9

Vertical Curves .....................................................................................................................................11

Horizontal Alignment ................................................................................................................................13

Superelevation Rate..............................................................................................................................13

Superelevation Runout..........................................................................................................................14

Sharp Curve Design--Widening on Curves ..............................................................................................15

Combination of Horizontal and Vertical Alignment.......................................................................................17

HAULAGE ROAD CROSS SECTION .................................................................................................................17

Sub base..................................................................................................................................................17

Surface Materials......................................................................................................................................20

Asphaltic Concrete................................................................................................................................22

Compacted Gravel and Crushed Stone ...................................................................................................23

Stabilized Earth ....................................................................................................................................25

Haulageway Width....................................................................................................................................25

Cross Slope ..............................................................................................................................................27

Conventional Parallel Berms ......................................................................................................................27

Traffic Signs.............................................................................................................................................29

Speed Limit Signs .................................................................................................................................29

Stop Signs............................................................................................................................................29

Curve and Intersection Warning Signs ...................................................................................................30

Culvert Crossing Markers.......................................................................................................................30

Traffic Control Signs .............................................................................................................................30

Limited Access Designators ...................................................................................................................30

Safety Access Indicators .......................................................................................................................30

Drainage Provisions ..................................................................................................................................30

Ditch Configuration and Location...........................................................................................................30

Ditch Capacity and Protection................................................................................................................31

Culverts ...............................................................................................................................................32

Location...........................................................................................................................................32

Type and Size ..................................................................................................................................33

Placement........................................................................................................................................34

Inlet-Outlet Controls .........................................................................................................................34

Typical Haulageway Sections.....................................................................................................................36
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ROAD MAINTENANCE CRITERIA....................................................................................................................38

VEHICLE MAINTENANCE CRITERIA ...............................................................................................................39

RUNAWAY VEHICLE SAFETY PROVISIONS .....................................................................................................41

Runaway Vehicle Collision Berms...............................................................................................................42

Escape Lanes ...........................................................................................................................................44

Entrance ..............................................................................................................................................44

Deceleration.........................................................................................................................................44

Stopping ..............................................................................................................................................45

CONCLUSIONS .............................................................................................................................................46

Appendix......................................................................................................................................................48
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Design of Surface Mine Haulage Roads – A Manual 

By 

Walter W. Kaufman and James C. Ault 

ABSTRACT

This Bureau of Mines manual for design of surface mine haulage roads covers such aspects of haulage road 

design as road alignment (both vertical and horizontal), construction materials, cross slope, and drainage provisions. 

Traffic control and design of proper lane widths to promote safe vehicle movement are included, as are suggested criteria 

for road and vehicle maintenance and for runaway vehicle safety provisions. The aim of this publication is to provide 

those involved with surface mine haulage road design with a complete manual of recommended practices that, if 

implemented, will promote safer, more efficient haulage routes. 

INTRODUCTION

During the past 30 years, surface mine haulage equipment has developed from trucks capable of moving 20 tons 

of material to vehicles that transport as much as 350 tons. Unfortunately, the design of roads this equipment must 

traverse has not advanced at the same rate. In many areas, road-building technology appropriate to vehicles of three 

decades past is still being practiced today. As a result, numerous unnecessary haulage road accidents have occurred 

every year. A number of these mishaps can be attributed to operator error. However, far too many are caused by road 

conditions that are beyond the vehicle's ability to negotiate safely. With this history of haulage related problems in mind, 

the Bureau of Mines undertook a project to produce a design manual that would ultimately guide surface mine road 

planners toward safer, more efficient haulage systems. Such a manual did not exist prior to the conclusion of this project. 

This manual was produced under a contract let by the Bureau of Mines to Skelly and Loy Engineers and Consultants. 

Information relating to the content of the manual was gathered through contacts with mining companies and 

equipment manufacturers across the country. Review of mining practices in some foreign countries also provided input. 

Literature sources relevant to good road design methods were reviewed and listed where appropriate in the text. 

It is the purpose of this document to identify the performance limitations of modern haulage equipment and to 

examine the impact of haulage road design on vehicular controllability. Based on these evaluations, haulage road design 

criteria that will promote continuity and safety throughout the haulage cycle were established. 

Time allocated for this project prohibited a detailed investigation of mechanical design for every type of haulage 

road user. However, safe road design criteria should be sufficiently comprehensive to allow application to all machine 

types. 

This complication required that design criteria be based on the one type of surface mining equipment that 

exhibits the lowest safety potential. Research of engineering data for all major types of surface mine machinery revealed 

that large off the road haulage trucks had the smallest margin of safety due to their great size and weight, characteristic 

use, and control components. Thus, designing haulage roads to accommodate these vehicles leaves a wide margin of 

safety for all other surface mining equipment. 

Extensive engineering data for all makes and models of large off-the-road haulage vehicles was solicited from 

manufacturers. Information was tabulated to identify specifications for width, height, weight, tire track, wheel base, type 

of braking system, steering ability, retarded performance, speed and range on grade, and numerous other factors for 

each truck model. Various models were then grouped into four weight range categories, and minimum, mean, and 

average specifications were identified for each weight category. 

Design guidelines for each weight category, including velocity stopping distance curves, vertical curve controls, 

haulage way widths, curve widening, and spacing of runaway devices, are presented in this report. 

The haulage way designer may utilize the Contents section of this report as a checklist to assure that all elements 

of design have been considered in planning the haulage road. 

HAULAGE ROAD ALIGNMENT

As far as is economically feasible, all geometric elements of haulage roads should be designed to provide safe, 

efficient travel at normal operating speeds. The ability of the vehicle operator to see ahead a distance equal to or greater 
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than the stopping distance required is the primary consideration. This section of the study addresses the effect of speed, 

slope, and vehicle weight on stopping distance, as well as design criteria for vertical and horizontal alignment. 

Stopping Distance--Grade and Brake Relationships 

From a safety standpoint, haulage road grades must be designed to accommodate the braking capabilities of 

those vehicles having the least braking potential which will most frequently traverse the haul route. In the majority of 

cases, rear, bottom, and side dump trucks, by virtue of their function within the mining operation, are the most frequent 

haulage road users. Due to their extreme weight and normally high operating speeds in relation to other equipment, their 

ability to decelerate by braking is lowest of the constant haulage road users. The design of routes that accommodate the 

braking systems of haulage trucks should leave a sufficient margin of safety for other equipment less frequently used, 

such as dozers, loaders, scrapers, graders, etc. 

Most truck manufacturers' specifications for brake performance are limited to an illustration of the speed that can 

be maintained on a downgrade through use of dynamic or hydraulic retardation. Although retardation through the drive 

components is an efficient method of controlling descent speed, it does not replace effective service brakes. In the event 

of retardation system failure, wheel brakes become the deciding factor between a halted or runaway vehicle. 

Unfortunately, very few, if any, truck manufacturers define the capabilities of their service and emergency 

braking systems in terms of performance. They are usually described by lining area, drum or disk size, method of 

actuation ' and system pressure. Thus, an operator does not know whether the brakes of the vehicle will hold on a 

descent grade in the event of a retardation failure. Because of the possible need to utilize service brakes as the sole 

means of halting or slowing a truck, their performance must be defined and taken into consideration in the design of safe 

haulage road grades. 

The Society of Automotive Engineers (SAE), realizing the need for effective brake performance standards, has 

developed test procedures and minimum stopping distance criteria for several weight categories of large, off highway, 

truck’s. SAE recommended practice J166 delineates the following values as maximum permissible service brake stopping 

distances from an initial velocity of 20 mph, on a dry, level, clean concrete surface: 

While the Majority of haulage truck manufacturers equip their products with brake systems that meet or exceed 

these criteria, there is no indication of how brake performance may vary with changes in grade, road surface, or initial 

speed. However, the stopping distance limitations set forth provide the basic data from which performance under 

different conditions may be mathematically deduced. 

 The stopping distance curves (figs. 1-4) depict stopping distances computed for various grades and 

speeds in each SAE test weight category. The points for each of the various curves have been derived using the formula 
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With the t and u min values identified, it is possible to use equation 1 and arrive at values illustrated in the 

stopping distance curves for different grade speed operating conditions. This formula, however, does not allow a 

determination of the distance at which constant brake application will result in excessive heat build-up and, consequently, 

cause fade or complete brake failure. 

Since it is unrealistic to assume that brakes can remain applied without fade for excessive periods of time, heat 

build-up must be considered. Unfortunately, factors influencing the ability of a brake system to dissipate heat vary to 

such an extent that accurate mathematic simulation is virtually impossible. In fact, there appears to be no definite 

conclusion as to the maximum temperature a brake system can withstand before negative effects are noticed. The 
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obvious need to limit stopping distances to prevent excessive brake heat, combined with the inability to realistically 

simulate thermal characteristics, presented a problem. 

Resolution of this difficulty was achieved through the acceptance of empirical test data from the British Columbia 

Department of Mines and Petroleum Resources. ('Dawson, V. E. Observations Concerning On Site Brake Testing of Large 

Mining Trucks. Pres. at Earthmoving Industry Conf., Central Illinois Sec., SAE, Warrendale, Pa. Apr. 15 16, 1975, 33 pp.) 

This organization has conducted more than 1,000 haulage truck stopping distance tests at active mine sites in British 

Columbia. The variety of truck makes and models included in the testing program present a representative brake 

performance cross section for many of the vehicles currently marketed. 

Information supplied by V. E. Dawson, who coordinated this testing, indicated that to preclude fade, a 200 foot 

braking distance should be considered the maximum allowable. Although some tested vehicles were able to exceed this 

limitation and still execute a safe, controlled stop, statistics indicate that a 200 foot restriction permits a reasonable 

margin of safety. Each stopping distance graph illustrates this 200 foot maximum braking distance as a vertical line 

increasing with velocity. Increases of distance for speed reflect footage consumed by driver perception and reaction time, 

factors not considered during actual tests. 

Inclusion of this stopping distance restriction completes the stopping distance graphs. Maximum operating speed 

and descent grade can be found for a known truck weight by reading vertically along the maximum permissible stopping 

distance limitation line. At grade curve intersections, read left to find velocity. An example is given on the graph for less 

than 100,000 pound trucks (fig. 1). 

Figures 1 through 4 have been based primarily on mathematic derivations. They do not depict results of actual 

field tests, but are presented simply to offer an indication of the speed and grade limitations that must be considered in 

designing a haulage road for a general truck size. Actual field testing has proven that many haulage vehicles can and do 

exceed theoretical capabilities. This empirical data, however, does not encompass a wide range of speed and grade 

situations. Therefore, use of this information would not permit sufficient design flexibility. 

It is recommended that the operational limitations depicted in these illustrations be used to make general 

determinations in the preliminary planning stage of design. Before actual road layout begins, manufacturers of the 

vehicles that will ultimately use the road should be contacted to verify the service brake performance capabilities of their 

products. In all cases, verification should reflect the capabilities of wheel brake components without the assist of dynamic 

or hydraulic retardation. 

The discontinuity between theoretical and empirical results substantiates the need for intensive and 

comprehensive brake evaluation programs. With the exception of British Columbia and possibly a few manufacturers, 

testing has been restricted to the somewhat idealistic SAE procedures. It is anticipated that continuing demands for 

larger equipment and the increasing safety consciousness of mine operators and employees will eventually make 

intensive testing programs a reality. 

Sight Distance 

Sight distance is defined as "the extent of peripheral area visible to the vehicle operator." It is imperative that 

sight distance be sufficient to enable a vehicle travelling at a given speed to stop before reaching a hazard. The distance 

measured from the driver's eye to the hazard ahead must always equal or exceed the required stopping distance. 

On vertical curve crests, the sight distance is limited by the road surface. Figure 5, case A, illustrates an unsafe 

condition. The sight distance is restricted by t17e short vertical curve and the vehicle cannot be stopped in time to avoid 

the hazard. Case B shows a remedy to the dangerous condition. The vertical curve has been lengthened, thus creating a 

sight distance equal to the required stopping distance. 

On horizontal curves, the sight distance is limited by adjacent berm dikes, steep rock cuts, trees, structures, etc. 

Case C illustrates a horizontal curve with sight distance restricted by trees and steep side cut. Case D shows that by 

removing the trees and laying back the slope, the sight distance can be lengthened to equal the required stopping 

distance.
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Vertical Alignment 

Vertical alignment is the establishment of grades and vertical curves that allow adequate stopping and sight 

distances on all segments of the haulage road. A safe haulage environment cannot be created if grades are designed 

without consideration for the braking limitations of equipment in use. The same is true for situations where hill crests in 

the road impede driver visibility to the point that vehicle stopping distance exceeds the length of roadway visible ahead. 

Design practices relevant to the foregoing parameters are presented in the following subsection. 

Maximum and Sustained Grades

Theoretical maximum allowable grades for various truck weight ranges in terms of emergency stopping situations 

have been defined in the stopping distance curves (fig. 1-4). Defining maximum permissible grades in terms of stopping 

capabilities alone, however, is somewhat misleading in that no consideration is given to production economics. If, for 

example, a road were designed to include the maximum grade a truck weighing between 100,000 and 200,000 pounds 

(category 2) can safely descend, speed at the beginning of that grade must be reduced and sustained for the duration of 

descent. By the same token, ascending equipment would require frequent gear reductions and similar speed losses. This 

changing velocity means lost production time, additional fuel consumption, component wear, and eventually, 

maintenance. 

Figure 6 is a performance chart similar in composition to those supplied by a majority of equipment 

manufacturers. Although the graph reflects performance characteristics for a specific make and model of haulage vehicle, 

it shows a representative impact of grade on performance. Two different symbols have been superimposed to delineate 

attainable speed as it is influenced by a vehicle operating on a 5% and 10% grade under loaded and unloaded 

conditions. 
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It is apparent from the chart that a reduction in grade significantly increases a vehicle's attainable uphill speed. 

Thus, haulage cycle times, fuel consumption, and stress on mechanical components, which results in increased 

maintenance, can be minimized to some extent by limiting the severity grades. 

By relating the 10% to 5% grade reduction to the stopping distance charts in the previous section, it can be seen 

that safety and performance are complementary rather than opposing factors. To demonstrate this fact, a reproduction 

of the stopping distance chart for vehicles in the 100,000-to-200,000 - pound category is presented in figure 7 for 

reference. As indicated by superimposed lines on the graph, a 5% grade reduction translates to a descent speed increase 

of 6 mph without exceeding safe stopping -distance limitations. 

The described benefits to production neglect consideration of construction economics. In the majority of cases, 

earthmoving to construct flatter gradients will incur greater costs. Moreover, design flexibility at many operations is 

curtailed by limited property ownership and physical constraints such as adverse geologic and topographic conditions. To 

recommend one optimum maximum grade to suit all operations, therefore, would be unfeasible. It must be the 

responsibility of each operator or road designer to assess the braking and performance capabilities of his particular 
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haulage fleet and, based on this data, determine whether available capital permits construction of ideal grades or 

requires steeper grades at the sacrifice of haulage-cycle time. 

The only guidelines that can definitely be set forth for maximum grade criteria are the laws and/or regulations 

currently mandated by most major mining States. Presently, a few States allow maximum grades of 20%. However, the 

majority of States have established 15% as the maximum grade. 

Length of sustained gradients for haulage road segments are yet another factor that must be considered in 

vertical alignment. Many mine operators have found optimum operating conditions reflected on maximum sustained 

grades no greater than 7% to 9%. Also, many State laws and regulations establish 10% as a permissible maximum 

sustained grade. However, this does not mean that vehicles cannot be safely operated on more severe downgrades. 

Significant improvements have been made in controlling downhill speed through hydraulic and dynamic 

retardation of drive components. Charts similar' to figure 8 are available for most modern haulage equipment and 

illustrate their controllability on downgrades. As indicated by the example, this particular vehicle is advertised as being 

capable of descending a 15% grade at 8 mph if geared down to second range. Thus, the vehicle can be kept to a speed 

that is within the safe emergency braking limitations. The chart does not, however, specify the retardation limits in terms 

of time or length of sustained grade. 

All retardation systems function by dissipating the energy developed during descent in the form of heat. In 

hydraulic systems, this is accomplished through water?cooled radiators; the dynamic method generally relies on aircooled 

resistance banks. It is possible to overheat either system if the combination of grade and length is excessive. 

Considering the foregoing factors, it is reasonable to accept 10% as maximum safe sustained grade limitation. 

Vertical Curves

Vertical curves are used to provide smooth transitions from one grade to another. Their lengths should be 

adequate to drive comfortably and provide ' ample sight distances at the design speed. Generally, vertical curve lengths 

greater than the minimum are desirable, and result in longer sight distances However, excessive lengths can result in 

long relatively flat sections, a feature that discourages good drainage and frequently leads to "soft spots" and potholes. 

Curve lengths necessary to provide adequate sight distance were computed as follows:
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The object height used in computing crest vertical curves was 6 inches. Although there is some support for an 

object height equal to the vehicle taillight height, we believe the relatively small increase in vertical curve length is 

warranted to cover such possibilities as a prostrate figure, an animal, or dropped gear on the road surface. 

To illustrate use of the vertical curve charts, first select the graph that indicates the lowest driver's eye height for 

vehicles in the haulage fleet. Then, from the stopping distance charts (fig. 14), find the required stopping distance for the 

appropriate operating speed, vehicle weight, and grade. Use the steeper of the two grades to take into consideration the 

most critical situation. Read right to intersect the appropriate algebraic difference and down to find vertical curve length. 

An example is given in figure 9 for a stopping distance of 200 feet and an algebraic difference of 16 (A 16) to give a 

required curve length of 325 feet. 

Horizontal Alignment 

Horizontal alignment during haulage road design and construction deals primarily with the elements necessary for 

safe vehicle operation around curves. Far too often turns are created without considering proper width, super elevation, 

turning radius, or sight distance. Correct horizontal alignment is essential to both safety and efficiency throughout a 

haulage cycle. The following subsections discuss the parameters prerequisite to correct horizontal alignment and how 

they affect road design. It must be emphasized that recommendations are based on the premise of providing maximum 

safety without taking construction economics into account. Due to the physical constraints particular to many mining 

sites, the cost of construction may increase significantly. Safety, however, should allow no tradeoffs, and any alterations 

to design criteria should be accompanied by a compensatory reduction in operating speed. 

Superelevation Rate

Vehicles negotiating short radius curves are forced radially outward by centrifugal force. Counteracting forces are 

the friction between the tires and the road surface, and the vehicle weight component due to the superelevation. The 

basic formula is 
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Theoretically, owing to superelevation, the side friction factor would be zero when the centrifugal force is 

balanced by the vehicle weight component. Steering would be effortless under these conditions. 

There is a practical limit to the rate of superelevation. In regions subject to snow and ice, slow travelling vehicles 

could slide down the cross slope. Regions not subject to adverse weather conditions can generally have slightly higher 

superelevation rates. However, even in these regions, the driver of a vehicle negotiating a curve at a speed lower than 

the design speed would encounter some difficulty holding the proper path. He would experience an unnatural 

manoeuvre, steering up the slope, against the direction of curve. 

Another consideration in establishing the cross slope rate is the high percentage of load carried by the inner 

wheels of a truck stopped or moving slowly on the curve. 

As shown by the formula, there are two factors counteracting the centrifugal force: The superelevation rate and 

the side friction factor. Much experimentation has been done to determine side friction factors. Several authorities 

recommend a factor of 0.21 for speeds of 20 mph and less. The American Association of State Highway Officials (AASHO) 

has plotted the results of several studies on vehicle speeds at short radius curve intersections. Logically, the average 

running speed decreased as the radius decreased. And, as the speed decreased, the side friction factor increased, 

producing a factor of 0.27 at 20 mph on a 90 foot radius curve, and a 0.32 factor at 15 mph on a 50 foot radius curve. 

Neither demonstrates a need for a superelevation rate in excess of the normal cross slope. 

This data, plus the recognized fact that sharper curves are shorter in length and afford less opportunity for 

providing superelevation and runout, lead to the derivation of table 1. 

Superelevation Runout

The portion of haulage way used to transform a normal cross slope section into a superelevated section is 

considered the runout length. The generally slower speeds at mining sites make the positioning of the runout less critical, 

but the purpose remains the same--to assist the driver in manoeuvring his vehicle through a curve. States vary in their 

methods of applying superelevation runout. Some apply it entirely on the tangent portion of the haulage way so that full 

superelevation is reached before entering the curve. Most States, however, apply part on the tangent and part in the 

curve. For design criteria herein, one third shall be in the curve and two-thirds on the tangent. 

Runout lengths vary with the design speed and the total cross slope change. Recommended rates of cross slope 

change are shown in table 2. 
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To illustrate the use of this table assume a vehicle is travelling at 35 mph on tangent with normal cross slope 

0.04 fpf to the right. It encounters a curve to the left necessitating a superelevation rate of 0.06 fpf to the left. The total

cross slope change required is 0.10 fpf (0.04 + 0.06). The table recommends a 0.05 cross slope change in 100 feet. 

Total runout length is computed as 200 feet [(0.10 / 0.05) X 100 = 200]. One third of this length should be placed in the 

curve and two thirds on the tangent. 

Sharp Curve Design--Widening on Curves

Switchbacks or other areas of haulage ways requiring sharp curves must be designed to take into consideration 

the minimum turning path capability of the vehicles. Figure 17 illustrates the turning radius of vehicles in each weight 

classification. The radii shown in the accompanying table are the minimum negotiable by all vehicles in each 

classification. Responsible design dictates that these minimums be exceeded in all except the most severe and restricting 

conditions. Figure 17 also illustrates the additional roadway width needed by a turning truck. Widths required by vehicles 

in each weight category vary with the degree of curve. Tables 3 and 4 recommend haulage way widths for curving 

roadways up to four lanes. 

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Combination of Horizontal and Vertical Alignment 

In the design of haulage roads, it is important that horizontal and vertical alignments complement each other. 

Poorly designed combinations can accent deficiencies and produce unexpected hazards. 

Although the alternatives available to a haulage road designer are limited, it would be prudent to consider the 

following potential problem conditions. . 

Avoid introducing sharp horizontal curvature at or near the crest of a hill. The driver has difficulty perceiving the 

curve, especially at night when the lights of his vehicle shine ahead into space. If a curve is absolutely necessary, start it 

in advance of the vertical curve. 

Avoid sharp horizontal curves near the bottom of hills or after a long sustained downgrade. Trucks are normally 

at their highest speed at these locations. 

If passing is expected, design sections of haulage road with long tangents and constant grades. This is especially 

important in two lane operations. 

Avoid intersections near crest verticals and sharp horizontal curvatures. Intersections should be made as flat as 

possible. Consider the sight distance in all four quadrants. 

HAULAGE ROAD CROSS SECTION

Sub base 
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A stable road base is one of the most important fundamentals of road design. Placement of a road surface over 

any material that cannot adequately support the weight of traversing traffic will severely hamper vehicular mobility and 

controllability. Moreover, lack of a sufficiently rigid bearing material beneath the road surface will permit excessive 

rutting, sinking, and overall deterioration of the travelled way. Thus, a great deal of maintenance will be necessary to 

keep the road passable. 

Surface mine operators often elect to forego the use of sub base materials and accept infringements on mobility 

in the interest of economics. In other words, it may be less expensive to permit the existence of some segments of the 

road that hamper, but do not prohibit, vehicular movement. rather than incur the cost of constructing a good road base. 

Although this appears economical at the onset of road construction, the eventual results will nearly always be 

undesirable. 

If the road surface is not constantly maintained, rutting will occur and create haulage intervals where vehicles 

must slow their pace to negotiate the adverse conditions. Over a period of time this will represent a considerable time 

loss to the production cycle. More importantly, these adverse conditions pose a serious threat to vehicular controllability 

and create unsafe haulage road segments. Therefore, it is important that stability of the haulage way be guaranteed 

throughout its length. 

In many surface mine operations, the road surface is underlain by natural strata capable of supporting the weight 

of any haulage vehicle. For example, in the case of bedded stone formations, it is sufficient to place only the desired road 

surface material directly on the bedded stone. However, the bearing capacity of other subsurface materials must be 

defined to determine if they can adequately support the weight of vehicles intended for use. 

Defining the bearing capacity of soils is a detailed procedure that should be accomplished by a qualified soils 

engineer. Only in this manner can the capacity of a particular soil be determined. However, general information is 

available on the bearing capabilities of various soil groups. 

The information in table 5, when compared with vehicle tire loads in pounds per square foot, identifies soil types 

that are inherently stable as road base and those that must be supplemented with additional material. The tire loading 

for most haulage vehicles filled to design capacity, with tires inflated to recommended pressure, will rarely exceed 16,000 

psf. Although the tire loading may be somewhat less, depending on the number of tires, their size, ply rating, and 

inflation pressure, and overall vehicle weight, this 

figure can be utilized when determining sub base requirements. Any subgrade that is less consolidated than soft 

rock will require additional material in order to establish a stable base; therefore, the designer must determine the 

amount of additional material that should be placed over the subgrade to adequately support the road surface. 

 

 

One of the most widely used methods of making this determination is through the use of curves commonly 

referred to as CBR (California Bearing Ratio) curves. This system, originally developed in 1942, continues to be used by 

highway designers for evaluating sub base thickness requirements in relation to subgrade characteristics. To be 

completely accurate, it necessitates CBR tests to precisely determine the bearing capabilities' of both subgrade and sub 

base materials. These tests can be conducted by a soil testing laboratory at relatively minimal cost simply by submitting 

samples of the subgrade and sub base materials. 

 
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The curves of figure 18 depict sub base thickness requirements for a wide range of CBR test values. To serve as 

a general indication of the sub base thicknesses required for various subgrade soil types, ranges of bearing ratios for 

typical soils and untreated sub base materials are included at the bottom of the graph. It must be emphasized that these 

ranges are extremely vague. Actual test results may prove the bearing ratios for a specific soil group to be considerably 

better then the low value depicted on the chart. Although it is not a recommended practice, the CBR ranges reflected by 

the graph may be utilized in lieu of actual test results if only general information is desired. In this approach, the lowest 

possible CBR value presented for a given soil type should be used. 

As shown by the curves, final sub base thicknesses are determined by vehicle wheel loads as well as soil type. 

Wheel loadings for any haulage vehicle can be readily computed from manufacturers' specifications. By dividing the 

loaded vehicle weight over each axle by the number of tires on that axle, the maximum loading for any wheel of the 

vehicle can be established. In every case, the highest wheel loading should be used for the determinations. When a 

wheel is mounted on a tandem axle, the value should be increased 20%. 

To provide a readily available indication of the wheel loading characteristics of currently manufactured vehicles, 

the chart is divided into three categories. Each category represents the range of wheel loadings, under fully loaded 

conditions, that may be anticipated for vehicles in a given weight class. Classifications do not represent the higher wheel 

loads that will be incurred by tandem axles in each weight range. 

After wheel loading and CBR values have been established, the chart may be employed to compute sub base 

requirements, as illustrated by the following example. It must be noted that the graphic plot for any wheel load never 

reaches zero. This "open" dimension is the depth allocated for the placement of final surface material. When the 

recommended thicknesses for various surfaces (as prescribed in the Road Surfacing section) fail to consume the open 

dimension, remaining space must always be filled with a sub base having a CBR of 80 or greater. Crushed rock is 

preferred. 
Page 20 of 49 

Example: A haulage road is to be constructed over a silty clay of medium plasticity with a CBR of 5. The 

maximum wheel load for any vehicle using the road is 40,000 pounds. Fairly clean sand is available with a CBR of 15 to 

serve as sub base material. Road surface is to be constructed of good gravel which has a CBR of 80. 

Step A. The 40,000 pound wheel load curve intersects the vertical line for a CBR of 5 at 28 inches. This means 

that the final road surface must be at least this distance above the subgrade. 

Step B. A clean sand CBR of 15 intersects the 40,000 pound curve at 14 inches, indicating that the top of this 

material must be kept 14 inches below road surface. 

Step C. An intersection of the 80 CBR for gravel and the 40,000 pound wheel load occurs at 6 inches. Since this 

will constitute the final surface material, it should be placed for the remaining 6 inches. Completed sub base construction 

for the foregoing conditions is described in figure 19. 

 

 

Following the determination of sub base depth requirements, proper placement procedures must be 

implemented. Regardless of material used, or depth, the sub base should be compacted in layers never exceeding 8 

inches. To insure stability of the final surface, sub base materials should exceed the final desired sur face width by a 

minimum of 2 feet and must always be compacted while moist. Proper compaction equipment usually consists of heavy 

rollers. However, few surface mine operators include rollers in their vehicle fleet. When rolling equipment is not available, 

an alternative such as heavy tracked equipment may be employed. Each 8-inch layer must be subjected to repeated 

passes of the compacting equipment until it fails to compress under the weight of the vehicle. 

Surface Materials 

The authors of this report have visited over 300 mining operations throughout the United States. At many of 

these mine sites, especially small coal mining and quarry operations, little consideration appeared to be given to the 

construction of a good haulage road surface. In fact, development of the haulage way is frequently accomplished by 

simply clearing a path over existing terrain. 

While this practice is undoubtedly the most economical means of road construction in terms' of initial cost, the 

benefit is seldom long lived. Failure to establish a good haulage road surface will result in increased vehicle and road 

maintenance costs and will severely retard the ability of a vehicle to safely negotiate the route. These difficulties are 

usually greatest on earth and bedded rock surfaces. Greater vehicle maintenance is required on rock surfaces as a result 

of excessive tire wear. It is virtually impossible to construct a bedded rock surface free of jagged edges. Thus, the tires of 

traversing vehicles are continually cut by scuffing. 

Earth roads, unless thoroughly compacted and stabilized, may cause both vehicular and road maintenance 

difficulties. Dust problems are frequent during dry seasons and, if not controlled, the dust can contaminate air filtration 

components, brakes, and other moving parts, making frequent replacement of these items necessary. Moreover, dust 

represents a major safety hazard to the vehicle operator in that it can become so dense that visibility is severely reduced. 

Eliminating the dust problem requires continual wetting of the surface, which represents yet another maintenance 

expenditure. When subjected to heavy wetting, non stabilized earthen roads become extremely slick and severely 
Page 21 of 49 

defaced by erosion. Thus, reduced vehicular controllability from a slippery surface creates a safety hazard, and 

maintenance must be increased to eliminate erosion gullies. Jagged rock and unconsolidated earth surfaces should 

always be avoided in a safe haulage road design. 

Many of the available road surfacing materials may be used to maximize safety and reduce road maintenance 

requirements. However, the field can be narrowed considerably by determining those which are most appropriate for use 

in haulage road construction. This determination is based on the road adhesion and rolling resistance factors 

characteristic of different surface types; that is, the resistance factors acting between the road and tire. Road adhesion 

coefficients play an important role in determining a vehicle's potential to slide. Since the principal concern is haulage road 

safety, primary emphasis should be placed on these characteristics. Table 6 shows coefficients of road adhesion, 

determined through years of research. for various surfaces. It must be noted that as the values decrease, the potential 

for a vehicle tire to begin sliding increases. 

A beneficial side effect of selecting a road surface that has a high coefficient of road adhesion for safety is that 

operational efficiency will increase as well. Rolling resistance has a direct effect on vehicular performance. It is commonly 

defined as "the combination of forces a vehicle must overcome to move on a specified surface." This factor is usually 

expressed in pounds of resistance per ton of gross vehicle weight caused by the bearing friction losses resulting from 

tires sinking in loose material. For the majority of road surface materials, an increase in coefficient of road adhesion can 

be directly related to a reduction in rolling resistance. Table 7 illustrates this point by presenting the rolling resistance 

values associated with several road surface materials and their road adhesion characteristics. The data in table 7 indicate 

that a good road surface will, in many cases, decrease operational costs by reducing resistance to travel. Thus, safety 

and economics, again. work together. 

Asphaltic concrete, crushed stone or gravel, and stabilized earth are the most practical construction materials for 

developing a haulage road surface that will insure maximum safety and operational efficiency. Because each of these 

materials has merits that are applicable to specific haulage situations, they are discussed separately in the following 

pages. 
Page 22 of 49 

 

Asphaltic Concrete
Page 23 of 49 

From a safety standpoint, asphaltic concrete appears the most desirable road surface material. It offers a high 

coefficient of road adhesion and creates a surface that reduces dust problems. In addition, the characteristic stability of 

this material creates a*smooth haulage surface that can be travelled with little fear of encountering deep ruts of potholes 

that would impede vehicular controllability. If potholes or ruts do appear, they can be readily corrected by patching. 

These surfaces are equally attractive from a production standpoint. While an increasing number of operators are 

beginning to utilize asphaltic concrete because of lower road maintenance costs, the smooth surface also allows haulage 

vehicles to travel safely at greater speeds. This speeds up the production cycle. 

A seasonal disadvantage to using this composition, however, is revealed during the first snow or freezing rain. 

The characteristically smooth surface of asphalt offers little resistance to development of an ice or snow glaze. Thus, the 

roadway can become extremely slick and remain so until corrective measures are employed. This could constitute a 

serious threat to operational safety in mining areas where rapid and frequent freeze conditions prevail. 

If asphaltic concrete is the chosen surface material, it must be applied within the constraints of good engineering 

practice. In order to be stable, it must be composed of asphalt binder, aggregate, and asphalt cement. The exact mixture 

for available material in a given locality may be obtained from State Highway Departments or local general paving 

contractors. 

Prior to placing the asphalt, a sufficient sub base must be established, followed by an additional layer of base 

course. Base course is a term designating the layer of stable material that must lie directly beneath asphaltic concrete. 

Although any material with a CBR of 80 or greater may be used for this purpose, crushed stone is recommended. Depth 

of base required will be entirely dependent on subgrade conditions and may be determined with some degree of accuracy 

by using the curves shown previously in figure 18. The example given in the figure illustrates that the final clean sand 

layer of subbase had to remain 14 inches below the final road surface. This is the dimension that must be filled by the 

combination of base course and asphaltic concrete. Thus, 10 inches of base course and 4 inches of asphalt are required. 

Unfortunately, the high cost of asphaltic road surface severely restricts its feasibility on roads of short life. Due to 

the extreme weight on the wheels of vehicles that constantly travel the haulage road surface, a 4 inch layer may be 

accepted as the minimum required in most cases. The cost of constructing a 4 inch thick layer ranges from $46 to $5 7 

per square yard for labour, equipment, and material. Using the higher figure for a 5 mile road 30 feet wide would 

necessitate an expenditure of $440,000 for paving alone. 

The placement of asphaltic concrete surface is an extremely detailed process that is dependent upon many 

variables. Temperature of the mix, compaction procedures, wetting, joining, and density control are only a few of the 

critical elements that must be considered during construction. Unless the mine operator is thoroughly familiar with all 

elements of asphalt placement or wishes to follow procedures outlined in State Highway Construction Manuals, a 

reputable paving contractor should be retained to do the work. Before construction of the road, asphaltic concrete should 

be tested on a small plot to note its adaptability to normal environmental and travel conditions in the area of intended 

application. 

The required base course is also an expense to be considered in the total construction cost. Many operators are 

capable of performing this operation with their own labour, materials, and equipment, thus minimizing its cost. 

Because of the relatively high cost of asphaltic concrete surfaces, each operator must determine if the benefits of 

increased speed and reduced road maintenance will offset the investment. In most cases, the determining factors will be 

the length of haul and required life of roadway. If roadway life is relatively short, an asphalt surface may be difficult to 

justify. If, on the other hand, the haulage road is to be considerably long and in service for a number of years, the 

placement of asphaltic concrete may be quite feasible. 

Compacted Gravel and Crushed Stone

A great number of surface mining operations throughout the country are presently utilizing gravel and crushed 

stone surface haulage roads. When constructed and maintained properly, both materials offer a stable roadway that 

resists deformation and provides a relatively high coefficient of road adhesion with low rolling resistance. The greatest 

advantage of gravel and stone surfaces is that safe and efficient roadways can be constructed rapidly at a relatively low 

cost. In areas where the haulage route is subject to relocation or must accommodate heavy tracked vehicles, it would be 

impractical to use a permanent surface such as asphaltic concrete. 

Determination of the depth of material to be placed follows the same procedure outlined for asphaltic concrete. 

The depth from surface required for the final subbase material used, as shown in figure 19, determines the thickness of 

gravel or crushed stone necessary for base and surface. 
Page 24 of 49 

In some cases, the base and wearing surface may consist of the same type of materials. For example, a crushed 

stone wearing surface may often overlay a crushed stone base. However, while base materials may consist of particles as 

great as 4 inches in size, the surface must be much more refined. The following specifications in table 8 present an 

example of a stone wearing surface that has proven suitable on mine haulage roads. Any crushed stone or gravel that 

meets or exceeds the specifications presented in the illustration will qualify as an adequate surface composition.

Bank gravel, which is a mixture of pebbles and sand, frequently exists at many mine sites and thus is usually a 

low cost surfacing material. Care should be taken, however, to remove boulders, cobblestones, vegetation, and other 

undesirable material before the gravel is spread. Other similar materials suitable for surfacing are fine blasted rocks, 

scoria, disintegrated granite and shale, cinders, volcanic ash, mill tailings, and slag. 

The percentage of fines in the gravel will affect surface stability in freezing or hot, dry weather. Therefore, roads 

that are subject to freezing should not have more than 10% fines to prevent muddy, sloppy conditions when thawing. 

Those subject to hot, dry weather should not have less than 5% fines in order to prevent drying and loosening. 

If proper subbase and base are established prior to placing top material, the depth of surface material need not 

exceed 6 inches. To achieve a uniform layer, placement should be accomplished with a motor grader or an equivalent 

piece of equipment. Following placement, the material must be thoroughly compacted to a 6 inch depth. It is 

recommended that either rubber tired or steel rollers be used for compaction. Heavy rubber tired vehicles can be 

employed when rollers are not available. However, rubber tired vehicles must be run repetitively to cover the entire road 

width, and compaction will not be quite as good. The following typical section (fig. 20) illustrates a haulage road cross 

section utilizing a crushed stone wearing surface for a wheel load of 40,000 pounds.

After a haulage surface is constructed with materials of this type, frequent road maintenance is required. Most of 

this maintenance will consist of periodic grading to remove small ruts and potholes that will inevitably be created by 

passing traffic. The exact maintenance schedule required will depend greatly on traffic, and it must be developed to 

accommodate conditions at each individual location. In some cases, traffic may be heavy enough to realize benefits from 

a continuous maintenance schedule. 

In most stone quarry operations, both gravel and crushed stone are readily available from the stockpiles of 

finished products. At other surface mining operations, crushed stone is often available from the blasting and excavation 
Page 25 of 49 

of rock overburdens. As a result, it is difficult to derive an exact construction cost. However, the expense of constructing 

gravel or crushed stone roadways is always considerably less than that of asphaltic concrete. 

Stabilized Earth

Stabilized earth is defined herein as any soil that, through special procedures or additives, has 

been transformed from a naturally unconsolidated state to a degree of stability that will ' accommodate 

the weight of haulage vehicles. Achieving this level of stabilization involves incorporating soil binders such 

as cement, asphalt, calcium chloride, lignosulfates, or hydrated lime. 

Although these materials will not create a sufficient haulage road surface, they can significantly 

reduce the quantity of base material required. In fact, often the various soil binders can be mixed directly 

with subgrade sol to create a platform for the road surface, making the construction of a subbase 

unnecessary. At other times soil binders will reduce the amount of subbase or base material required. The 

potential of a specific binder to reduce or make unnecessary subbase or base material depends on the 

inherent strength of the material with which it is to be incorporated and the weight of vehicles that will 

use the haulage road. Final determinations of feasibility must be made by a qualified soils engineer who 

has evaluated the effects a binder will have on the subgrade or base material at a particular haulage road 

location. The application of various additives can be discussed in general terms, however. 

Asphalt impregnation and soil cementing, by virtue of their somewhat higher costs, should be 

utilized primarily for permanent haulage roads. On occasion, they may prove beneficial in areas where the 

subgrade is extremely weak and would require large quantities of offsite subbase for stabilization. In 

these instances, the addition of asphalt and portland cement to small quantities of fill material can create 

a stable base. 

Calcium chloride, lignosulfates, and hydrated lime are more economical than asphalt impregnation 

and soil cement, but are not nearly as effective. These substances are best employed to supplement 

crushed stone or gravel bases to increase their mechanical stability. Although the construction of any 

haulage road will benefit from the use of these additives, they are most applicable for road segments that 

are subject to constant relocation. 

If the operator wishes to use any of the materials previously described, two publications 8 may be 

consulted to determine the type and volume required for a particular situation. 

Haulageway Width 

The haulage road designer must be very concerned about the road width. Sufficient room for manoeuvring must 

be allowed at all times to promote safety and maintain continuity in the haulage cycle. Unlike passenger and commercial 

vehicles which have somewhat "standardized" dimensions, surface mine machinery varies drastically in size from one 

production capacity rating to another. Thus, requirements have to be defined for particular sizes rather than for general 

types. Complicating the problem is the need to specify additional widening for straight road to curve transitions. 

Because of the large number of influencing variables, the following guidelines for determining width are 

separated into individual categories. Recommendations presented are values for the size of travelled lane to be provided 

and do not take into consideration the additional dimensions necessary for subbase outslopes, drainage facilities, berms, 

etc. These items are discussed separately, and their dimensions must be added to those of the lane to determine the 

total roadway width. 

Width criteria for the travelled lane of a straight haul segment should be based on the widest vehicle in use. 

Designing for anything less than this dimension will create a safety hazard due to lack of proper clearance. In addition, 

narrow lanes often create an uncomfortable driving environment, resulting in slower traffic, and thereby impeding 

production. 

Rules of thumb for determining haulage road lane dimensions vary considerably from one reference source to 

another. Many of the guidelines specify a constant width to be added to the width of the haulage vehicle. This method is 

sufficient for smaller vehicles, but it is not advisable for computing lane spans to accommodate larger machines. To 

compensate for the increase in perception distance created by greater vehicle width, the space allocated for side 

clearance should vary with vehicle size. 

A practical guideline for establishing the vehicle to lane width ratio is contained in the 1965 AASHO Manual for 

Rural Highway Design. The AASHO Manual recommends that each lane of travel should provide clearance, left and right 
Page 26 of 49 

of the widest vehicle in use, that is equivalent to one half the vehicle width. Adding credence to this recommendation is 

the fact that a number of the larger surface mines base their haulageway spans on this criterion. By incorporating this 

guideline, both safety and efficiency will be enhanced. 

Table 9 and figure 21 illustrate the recommended widths that should be provided for various lane configurations 

based on the design vehicle dimension, along with a typical section depicting how multiple lane dimensions accrue.

Data presented in this chart is*intended to serve as guiding criteria for primary haulage road users. Special 

consideration must be given to road segments that may have to accommodate larger equipment such as shovels, 

draglines, drills, etc. A safety hazard will exist if the design road width is less than that necessary for the movement of 

such equipment. Prior to selecting a final design width, make the following assessments, and establish a dimension 

sufficient for all possible users: 

1. Define the width of all equipment that may have to travel the haulage 

2. Solicit dimensional data for any anticipated new machines. 

3. Determine the overall width of any equipment combinations that may be involved in a passing situation. 

4. Delineate the location of road segments requiring a greater than normal width. 

In cases where the passage of unusually wide machinery is occasional, there is no reason to establish additional 

lane width equal to half that of the vehicle. Although in most instances table 9 will serve as an excellent guide for the 

road designer, there are exceptions for single lane construction that must be acknowledged. 

The lane widths illustrated in the table for one lane construction apply only when the stopping distance of the 

haulage vehicle is exceeded by sight distance. On haulage segments where the opposite is true, a single lane span 

equivalent to 2 112 times the vehicle width is advisable. This will allow sufficient space for moving vehicles to avoid 
Page 27 of 49 

collision with others that might be stalled or otherwise incapacitated on the haulage route. Haulage road planners must 

also consider the fact that the minimum width recommendations for single lane roads, even when sight distance is 

adequate, do not allow sufficient room to pass. If a vehicle should become inoperable on the road, it would restrict the 

movement of any vehicle equal in size. To prevent this occurrence it is recommended that a minimum of 4 feet of 

additional lane width be provided over the entire haulage route. 

Cross Slope 

Cross slope, the difference in elevation between the road edges, must be given consideration during haulage 

road design and construction. From the standpoint of reducing a driver's steering effort, a level surface would be most 

beneficial. Adequate drainage, however, requires that a cross slope be created. To accommodate both drainage and 

steerability, balance must be established between a level and sloped configuration. The rate of cross slope that will allow 

a rapid removal of surface water without adversely affecting vehicular control must be determined. 

Both the theoretical and practical aspects of initiating a constant drop across the breadth of roadways have been 

studied and documented for years.10 Although the majority of this work has been conducted in relation to urban and 

rural highway design, the criteria developed are equally applicable to surface mine haulage roads. In nearly every 

published reference, the recommended rate of cross slope for surfaces normally constructed on mine haulage roads is a 

1/4 inch to 1/2 inch drop for each foot of width. 

Mine operators should consider one quarter to one half inch per foot as the limiting criteria for design. Special 

consideration must be given to determining when to use the maximum and minimum rates since the applicability of each 

depends on surface texture. 

Cross slopes of one quarter inch per foot are applicable to relatively smooth road surfaces that can rapidly 

dissipate surface water. In most cases, minimum slope is best suited to surfaces such as asphaltic concrete. However, 

there are conditions which warrant the use of 1/4 ipf criteria for surfaces of lesser quality. When ice or mud are constant 

problems, excessive cross sloping can cause vehicles to slide. This possibility is especially pronounced at slow operating 

speeds on grades of more than 5%. Therefore, where an ice or mud problem cannot be feasibly eliminated, cross slopes 

should be limited to the minimum value. Road maintenance should insure that the road surface is kept smooth and drains 

properly. 

In situations where the surface is relatively rough or where ice or mud is not a problem, a 1/2 ipf cross slope is 

advisable. The greater inclination permits rapid drainage and reduces the occurrence of puddles and saturated subbase, 

which can weaken road stability. On well constructed gravel and crushed rock roads, the 1/2 ipf criteria is preferable. 

Of equal importance to the degree of slope is the direction it should take in relation to various road 

configurations. Since the placement of high and low lane edges determine slope direction, it is necessary to define the 

circumstances under which the left edge should be higher than the right or vice versa. In the case of multiple lane 

construction, both sides of the final pavement may be equal. with a high point or "crown" at one of the intermediate lane 

edges. 

The cross slope direction for single lane construction is governed by adjacent land features. In cases where the 

haulage road is cut into existing ground, the high lane edge may be placed on either side. However, on fill sections, the 

highest lane edge should be nearest the most severe outslope. 

For two , three , and four lane surfaces, a crown is appropriate. On dual and four lane roads, the cross slope 

should be constructed to provide a constant drop at the recommended rate from the centre point of the roadway. The 

location of crown on three lane haulage roads must insure a continuous drop across two lanes in one direction and the 

same slope across the other in the opposite direction. The two lanes sloping toward the same edge of road should be 

lanes for vehicles travelling in the same direction. 

Conventional Parallel Berms 

The use of berms has long been accepted as a standard safety feature in areas where a haulage vehicle could 

accidentally run over the outslope of a haulage road. The applicability and effectiveness of berms were analysed to 

establish governing criteria for their design and placement in a typical haulage road operation. 

During an exhaustive literature search into similar investigations conducted in the interest of highway safety, 

many variables were found to govern the response of a vehicle to encountering a berm. Studies have shown the 

interaction of vehicular dynamics and berm characteristics determine whether a vehicle will impact a berm, deflect off it, 

or mount and climb over it. All relevant areas of primary research dealt with passenger cars encountering conventional 
Page 28 of 49 

berms at highway speeds. No information was available on vehicles with the characteristics of those normally found in 

surface mine operations. It is this lack of information in the area of large vehicles that restricted the development of this 

phase of the project . 

The adaptability of available berm information is doubtful in view of the basic differences in vehicle design. Table 

10 illustrates the typical relationships between an intermediate size passenger car and large haulage vehicle. 

Using this and other accepted data as a basis for rationalization, various conjectures can be made concerning a 

haulage vehicle's response to a berm. The enormous weight of a typical haulage vehicle is a major consideration. 

The weight would have significant deformational effect upon the berm resulting in a reaction pattern that would 

be an atypical response to the normal berm cross section. The high centre of gravity in combination with a 

disproportionately narrow width of the wheel track make haulage vehicles more susceptible to overturn than passenger 

cars. The differences in tire size and steering mechanism reduce the tendency of haulage vehicles to redirect themselves 

when encountering a berm. Other factors such as inertial characteristics, sprung mass ratio differences, and suspension 

characteristics indicate significantly different response patterns for haulage vehicles when compared with those of 

passenger cars. 

Assuming that a haulage vehicle would respond in a similar manner to a passenger car in a microscale situation, 

a proportionally sized berm would be approximately 20 feet high for the average haulage vehicle shown in table 10. It is 

not possible for such a berm to be economically constructed and efficiently maintained. For a normal berm sideslope of 

1.5:1, the additional bench alone necessary to accommodate a berm of this size would be 60 feet. 

It was determined from the literature review and analysis that a simplified approach to sizing haulage road berms 

that does not take into consideration vehicular dynamics would require substantial field testing. An alternative approach 

would involve an in depth investigation of haulage vehicle dynamics and a subsequent computerized simulation model 

analysis. This approach would allow the predictive analysis of a variety of vehicle and berm interactions and require only 

sufficient testing to verify the modelling procedure. 

Since the level of endeavour necessary to adequately define the response of a haulage vehicle to a berm is far 

beyond that originally conceived in the scope of this project, current berm sizing and placement were investigated and 

documented. This approach allows the standardization of practices that are currently in use, and also permits qualitative 

discussion of the supporting logic and experience upon which berm rationale has been, and is being, based. 

Information gathered during pertinent field investigation provided substantial insight into berm configurations 

and applications that have met with a degree of success in present haulage operations. In addition, data regarding berms 

was gathered from Canadian and other international sources. 

There are two principal berm designs that are in common use. One is the typical triangular or trapezoidal berm 

formed typically from unconsolidated, relatively homogeneous material obtained during overburden removal or from 

material obtained as a result of the haulage road construction itself. The effectiveness of this type of berm in redirecting 

a vehicle is dependent primarily on the natural angle the berm construction material assumes after being deposited. The 

steeper the side slope of berm, the more effective the berm is at redirecting the vehicle, all other factors remaining 

equal. The inherent tendency of these berms to redirect rather than impact and deflect is a definite advantage in terms 

of potential vehicle damage in the event of an encounter. It should be emphasized, however, that the redirectional 

effectiveness of berms is reduced as the angle of incidence is increased, and that this type of berm would tend to 

overturn the trucks if the wheels continued to climb the berm. Also, maintenance of these berms can be troublesome if 

the berm material is subject to erosion. 

The other most common berm consists of large boulders lining the haulage road with an earthen backing 

material. This type of berm presents the impacting vehicle with a near vertical face that deflects the vehicle for slight 

angles of incidence. Although more difficult to build, this type of berm offers distinct advantages in terms of berm 

maintenance. The basic limitations imposed by this configuration are (1) substantial damage to the vehicle can result 

from its use, (2) the vehicle would tend to impact the berm at sharp angles of incidence (possibly injuring the driver), 

and (3) the local geologic and topographic characteristics of the mining area must accommodate construction of the 

berm. 
Page 29 of 49 

Height is the main factor to be considered in designing berms. For conventional berms, the rule of thumb 

regarding height is that for a berm to possess any measurable tendency to redirect a haulage vehicle, its height must be 

equal to or greater than the rolling radius of the vehicle's tire. At moderate vehicle speeds, this height allows sufficient 

time for the driver of the vehicle to apply corrective measures before the truck either overturns or mounts the berm. 

Additionally, for the natural angle of normal berm building materials, this height of berm does not require a large amount 

of additional bench. As a result, it offers basic economic advantages. Berms lesser in height than the rolling radius of the 

vehicle * tire do not allow the driver sufficient response time before the truck mounts and straddles the berm or overruns 

the berm entirely. Additionally, small berms do not have adequate lateral resistance to effectively assist in redirecting a 

haulage vehicle. 

 For boulder faced berms, the height of the berm should be approximately equal to the height of the tire of the 

haulage vehicle. This allows an encountering vehicle to impact the berm at a point sufficiently high on the chassis to 

reduce the potential for overturning, while also improving the deflectional tendencies of the berm as a whole. 

The placement of berms on a haulage road must be based on the topographical characteristics of the mining 

area as well as on common sense. Whenever the potential exists for an accident that could be avoided by the existence 

of a berm, the initial cost of constructing and extended cost of maintaining a berm is small in comparison to alternative 

safety features. If the berm is successful once in preventing a potentially serious accident, it has more than paid for itself 

in relation to the costs of haulage equipment replacement as well as in lost production time. 

In summary, the contribution of a berm to the overall safety of a haulage operation depends upon a multitude of 

factors. A poorly designed or badly maintained berm could conceivably be worse than no berm at all. If a berm is to be 

built, the mine operator must consider the purpose for which it would be used, the available materials and technology 

that can be economically applied to its construction'. and its long term advantages from both a safety and an economic 

standpoint. 

As well as being a safety factor for haulage vehicles, berms serve many other useful purposes; for example, as 

marking devices for the edge of haulage roads; as drainage channelling devices preventing the uncontrolled erosion of 

out slopes, as fixed points of reference for haulage vehicle operators, and as effective safety devices for smaller 

maintenance vehicles that use the haulage road.

Traffic Signs 

Every road in the United States that is publicly maintained uses signs to delineate stopping points, curves, speed 

limits, street names, intersections, etc. Through years of practical application, these devices have proven to be extremely 

effective in accident prevention. 

The installation of warning and instructional signs can be equally as effective in promoting safety on surface mine 

haulage roads. However, unlike conventional roads, haulage routes experience traffic from vehicles that are controlled by 

the same operators day after day. Thus, the drivers are usually thoroughly familiar with all, aspects of the roads they 

travel. As a result, designers can be much more selective in their placement of traffic signs. In the surface mining 

environment, these safety devices should be viewed as reminders rather than as first warning measures. 

A number of signs that should be considered for use along surface mine haulageways are discussed in the 

following sections. 

Speed Limit Signs

Speed limits should be posted on segments of the haulage route that require slower than normal rates of travel 

to safely negotiate a hazardous condition. Some of the more advantageous locations for posted speed limit reductions 

include road segments that precede 

Changes in descending haulage road grades; 

Entrances to congested areas, such as pit, crusher, maintenance areas, overburden dumping points, vehicle 

crossings, etc.; 

Unusual road alignments, such as severe vertical and horizontal curves, narrow lanes, and areas of restricted 

sight distance; and 

Areas subject to material spills or other frequent obstructions. 

Stop Signs
Page 30 of 49 

From a production viewpoint, it is best to avoid interruptions in the .haulage cycle; however, this may not be 

compatible with road safety. Although vehicle stopping points along the haulage route should be kept to a minimum, they 

must be considered necessary for safety in some cases. Areas where the placement of stop signs should definitely be 

considered are as follows: 

Any secondary access road at the point it intersects with the main haulage way; 

Intersections where sight distance does not exceed vehicle stopping distance for the recommended travel rate; 

and 

Haulage road intersections with public roads. 

Curve and Intersection Warning Signs

These signs can provide the driver with a warning of upcoming situations where he should exercise caution. 

These devices are best restricted to positions in advance of the most critical curves and heavily travelled intersections. 

Culvert Crossing Markers

Whenever a culvert headwall or outlet is encountered beside the road, it should be marked with a standing 

reflector. 

Traffic Control Signs

A sign must be provided at all points in the haulage cycle where the driver is required to perform a special 

manoeuvre (Keep Right, One Way, No Left Turn, Do Not Pass, Sound Horn, Blasting Turn Off 2 Way Radios, etc.). 

Limited Access Designators

Private Property, Keep Out, or other signs of this nature are required at all haulage way and public road 

intersections to keep passing motorists from inadvertently wandering into the operation. The small size of passenger 

vehicles combined with the limited sight distance of many large haulage trucks constitutes a safety hazard. 

Safety Access Indicators

The location of all safety features such as escape lanes and median barriers should be signally depicted well in 

advance of their position. In addition to indicating the immediate entrance to these facilities, distances should be marked 

along the haulage road at minimum intervals of 250 feet. 

The preceding brief discussion of signs is intended to illustrate the traffic signs that should receive primary 

consideration. Each surface mine haulage road exhibits its own peculiarities and may require more or less signal 

definition. In any case, proper care must be taken to insure that all signs installed are at a height and location that is 

within the eyesight of drivers operating vehicles with the most restricted visibility. 

Drainage Provisions 

Soil erosion by water is a common problem that can plague the operation of safe and workable haulage roads. 

Erosive action on haulage roads can cause ruts and washouts, and can saturate the soil, causing instability. The proper 

use of drainage facilities can alleviate this problem, resulting in safer, more efficient haulage roads. 

Ditch Configuration and Location

Many factors influence final ditch configuration, including soil type, depth of road base, storm design frequency 

local restrictions, percent of grade, and predicted runoff from contributing land areas. However, general 

recommendations may be made to provide the operator with basic design concepts. V ditches are recommended for 

nearly all applications, owing to the relative ease of design, construction, and maintenance. 
Page 31 of 49 

The ditch cross slope adjacent to the haulageway should be 4:1 or flatter except in extreme restrictive 

conditions. In no case should it exceed a 2:1 slope. 

The outside ditch slope will vary with the material encountered. In rock it may approach a vertical slope; in less 

consolidated material, a 2:1 slope or flatter. 

The ditch should be located in undisturbed earth or rock; avoid placing ditches through fill areas. 

In a cut fill section, slope the haulageway toward the high wall. Carry drainage in a single ditch. 

In a total cut section, carry drainage on both sides. 

In fill sections, protect the toe of slopes with parallel interceptor ditches. 

Ditch Capacity and Protection

Ditches must be designed to adequately handle expected runoff flows under various slope conditions. The 

primary consideration is the amount of water that will be intercepted by the ditch during a rainstorm. Various methods to 

determine runoff flows are described in a separate section. 

After runoff flows are calculated, ditch design becomes a function of percent of grade, V configuration (4:1, 2:1, 

etc.), and depth of flow. In the V ditch, as well as other configurations, depth of flow depends on percent of grade and 

the texture of material lining the ditch. Loose and porous linings and low percentage grades reduce flow rates and 

increase depths; smooth, impervious linings and steeper grades create the opposite effect. To alleviate excessive erosion 

that may result from high flow velocities, certain ditch lining materials must be incorporated as the grade increases, 

except when the ditch is in nonerodable material. Some general rules to be followed for various grades in erodable soils 

are designated below. Please note that these are "general rules" and are by no means recommended to supersede State 

or local regulations. 

At a 0% to 3% grade, the ditch may be constructed without benefit of a liner except in extremely erodable 

material such as sand, or easily weathered shales and silts. 

At a 3% to 5% grade, the ditch should be seeded and protected with jute matting until a substantial grass lining 

can be established. 

At grades over 5%, the lining should consist of dumped rock placed evenly on both sides to a height no less than 

0.5 foot above the computed maximum depth. 

Following this section are simplified charts that depict the depth of water that may be anticipated in various ditch 

configurations depending on the contributing flow in cubic feet per second, the percent of grade, and the type of material 

utilized as a liner. To determine the runoff flow that may be anticipated for a given ditch segment, the operator should 

first consult his State or local agencies for preferred methodologies to be used in estimating runoff. If no specific 

guidelines are given by these sources, the necessary information may be obtained from chapter 2 of the Engineering 

Field Manual for Conservation Practices." This manual outlines the procedures for estimating runoff and contains all the 

data necessary to compute runoff volumes for all regions of the country. 

When utilizing the Soil Conservation Service Engineering Field Manual to develop peak flow rates, the 10 year, 24 

hour storm charts should govern. The rainfall intensity generated by a 10 year storm is recognized as the applicable 

standard for road drainage design by the American Association of State Highway Officials. Moreover, the volumes of 

water associated with this type of storm are well in excess of normal runoff conditions and necessitate the design of 

drainage facilities capable of handling extreme, rather than mean, rainfalls. 

In the event that a ditch grade must be altered to accommodate changes in topography, the depth of the ditch 

must be changed accordingly. Whether an increase or decrease in grade occurs, new volumes should be computed based 

on the flow in the preceding ditch segment and the volume of water generated by the contributing area contiguous to the 

new grade. 

By consulting table 11, the appropriate ditch depth needed to accommodate a specific volume of water may be 

derived. After determining the slope and finding the waterflow (in cubic feet per second), consult the corresponding ditch 

configuration table where the cubic feet per second is found. At the extreme left of this line will be the depth necessary 

to accommodate the flow for that ditch configuration. 
Page 32 of 49 

In some cases, additional depth may be required. In all cases where a subbase must be placed, the depth of the 

flow must not exceed the lower level of the subbase material. In cases where a freeboard is required, the depth of any 

ditch shall exceed the centreline depth of flow by a minimum of 0.5 foot. Where placement of a ditch lining material is 

recommended, it shall also be increased 0.5 foot on each side. 

It is important to note that the ditch should be kept free at all times of debris or any material that would alter 

design capacity. 

Culverts

Culvert sections are the most efficient and effective means of conveying free flowing drainage away from the 

haulage road, and must be incorporated to alleviate the potential of water overflows onto haulage road segments. Any 

accumulation of water on the haulage road can seriously impede vehicular control and promote road degradation. 

To achieve the most efficient drainage scheme, the designer must consider culvert location, sizing, placement, 

and inlet/outlet controls. Numerous factors affect each of these design considerations. Therefore, each parameter is 

discussed as a separate category on the following pages. 

Location 

Culverts should be located at all ditch low points unless natural water courses are present. 

A culvert should be installed at all road intersections and prior to switchback curves on the upgrade beginning of 

curvature. 

Whenever a haulage road segment requires a transition from a through cut to a cut fill, a culvert should be 

installed to intercept drainage p prior to spilling over an outslope. 
Page 33 of 49 

Culverts should be placed in natural watercourses intersected by the haulage road. 

In cut fill sections, culverts may be placed at various intervals along the ditch to intercept drainage and convey it 

to natural drainways below the fill slope. This procedure can significantly reduce the size of the ditch required by 

breaking runoff areas into small segments that contribute only to specific ditch segments. 

In some instances, culvert intervals will be the designer's option. However, spacing requirements 

are often specifically delineated in State or local codes of construction practice~ A typical example is the 

regulation imposed by the West Virginia Department of Natural Resources DivisionofReclamation.12 

This agency requires the spacing of culverts for ditch relief at various road grades as noted: 

Road grade, percent Spacing of Culverts, feet

2-5 300-800

6-10 200-300

11-15 100-200

The preceding illustration exemplifies the need to research all State or local standards prior to any design 

decisions. If there are no regulations regarding culvert spacing, the following is recommended: 

Spacing should not exceed 1,000 feet on grades from zero to 3%. 

Spacing should not exceed 800 feet on grades from 3% to 6%. 

Spacing should not exceed 500 feet on grades from 6% to 9%. 

Spacing should not exceed 300 feet on grades 10% or greater. 

Type and Size 

For the majority of haulage road culvert installations, corrugated metal pipe is most appropriate. Since this type 

of pipe is relatively light, high in strength, and usually readily available, it can be easily adapted to a variety of situations. 

Although other materials can be utilized, corrugated metal is currently used extensively throughout the surface mining 

industry. 

Regardless of material, the culvert must be able to accept the maximum runoff flow from the drainage ditch to 

be completely effective. Also the pipe diameter must be large enough to accept maximum flow without creating a backup 

at its inlet. Figure 22 may be utilized to determine pipe sizes for various flows. Flows in cubic feet per second on the left 

side may be read to their intersection with the diagonal graph line and then down to the corresponding minimum pipe 

diameter necessary to accept the flow. This minimum is indicative of a full flowing pipe without any water backup at the 

inlet. In some cases, however, it may be desirable to place a smaller, less expensive pipe and allow a small backup of 

water. The dashed lines on the chart (labelled '11rl) are included to depict how much head will be created behind the 

pipe if its size is restrictive. To determine the amount of head created by a given pipe size and cubic feet per second, 

read from the cubic feet per second column until the dashed line is intersected, then down. For example, a flow of 8 cfs 

intersects 2 feet of head at the 15 inch pipe diameter, thus 8 cfs of water at the inlet side of a 15 inch pipe will pond 9 

inches above the top of the pipe (2 feet minus 15 inches). However, it must be emphasized that the practice of creating 

an inlet head is discouraged. The most beneficial design requires that a pipe handle the entire volume of water without 

backup. If the example for cfs were to be followed without creating a backup, the intersection of the diagonal will show 

that a pipe diameter of approximately 21 inches is required.
Page 34 of 49 

Placement 

After the location and pipe size have been selected and the pipe is ready for placement, consideration must be 

given to depth of cover over the pipe in relation to the vehicles that will use the road. It is suggested that for support of 

vehicle weight under 100,000 pounds, a. minimum cover of 2 feet over the pipe be used. For support of vehicle weights 

over 100,000 pounds, minimum cover should be 3 feet 

In all cases, the fill should be hand tamped in 4inch layers from the bottom of trench to provide a stable, 

compacted base for the culvert. 

Inlet-Outlet Controls 

At all culvert inlets, a protective encasement or "headwall" consisting of a stable nonerodable material should be 

provided. 

Regulations specifying erosion and sediment control devices to be utilized at storm drain outlets have been 

developed by the U.S. Department of Agriculture, Soil Conservation Service. In addition, many States have adopted their 

own regulations for this purpose. By contacting one or both of these agencies in the region, the operator can determine 

the requirements that apply specifically to his operation. However, there are two rules of thumb to follow: 

Flow from ditches or culverts shall never be discharged over a fill outslope. In fill situations, the discharges must 

be conveyed away by pipes, flumes or ditches lined with nonerodable material. 

At any discharge point, where flow velocity exceeds the Soil Conservation Services recommended maximum for 

various soil types, erosion protection must be provided . Examples are shown in figure 23. 
Page 35 of 49 
Page 36 of 49 

Table 12 depicts the various treatments that may be anticipated for erosion control dependent on discharge 

velocity. Details are presented in figure 24 for the riprap and energy dissipater treatment techniques as a guide for 

proper construction. The lengths of these devices will be entirely dependent on slope lengths and must be determined for 

each individual situation.

Typical Haulageway Sections 

All of the criteria for proper haulage road cross section design are depicted in figure 25: design considerations for 

a typical cut section, a typical fill section, and a typical cut fill section. The type of section applicable to any particular

haulage road is, of course, dependent upon the contour of the original ground surface. However, figure 25 and the 

recommendations provided throughout this section of the report as a guide, all of the most important parameters that 

must be considered during design of cross sections will be covered. Particular attention should be paid to road cross 

slopes and drainage ditches since these will contribute greatly to good drainage and, therefore, more effective erosion 

control.
Page 37 of 49 

 

Key 

1 - Lane edge to centerline of ditch Dimension varies with centerline depth (6) and 

required slope (7). 

2 - Lane width Based on dimension of largest vehicle and numbers of lanes desired. 

3 - Typical cross slope for excavated subgrade and final surface Either 1/4 or 1/2 ipf, 

depending on surface material used. 

4 - Combined surface and subbase Depth varies with wheel load concentration. 

5 - Ditch outslope Natural angle of repose in rock, 2:1 in all soils. 

6 - Depth at centerline of ditch Required to be below subbase and deep enough to accept 

total volume of runoff from adjacent drainage area. 

7 - Ditch slope adjacent to roadway Varies from 4:1 to 2A. 

8 - Road widening to accommodate safety berm Dimension varies with berm size required. 

9 - Safety berm Constructed with a near vertical slope adjacent to lane edge, final height 

and outslope of berm depends upon the rolling radius of the largest tires that will traverse 

the haulage road. 

10 - Berm support Constructed to subbase material only; surface material ends at berm 

face. 
Page 38 of 49 

11 - Fill slope Descending at natural angle of repose, fill consists of material cut from 

existing ground of other excavated material from the mining operation. 

12 - Fill bench Required when original ground slope is 1:1 or greater, benches should be 

cut 8 feet~10 feet horizontally with an 8 to 10 foot vertical lift at 1/2:1; begin at toe of 

original ground slope and continue benching until road subgrade is reached. 

ROAD MAINTENANCE CRITERIA

Regardless of how meticulously a haulage road is planned and constructed, its surface is bound to be deformed 

by the constant pounding of haulage vehicles. Although deterioration may be controlled to a great extent by the type of 

surface material employed, the mine operator must still regard a road maintenance schedule as necessary to safety and 

economics. 

Dust, potholes, ruts, depressions, bumps, and other poor surface conditions can and will occur on any road 

surface. If left uncorrected, they may impede vehicular control and damage haulage machinery. 

When a rolling tire encounters a surface scar, there is a tendency to deflect from its normal direction of travel. 

Thus, the driver is forced to compensate for the abnormality by increasing his steering effort. If surface deformation is 

too great or if the driver is not aware of it before impact, complete loss of control may result. Often, even though the 

driver is able to negotiate a surface irregularity by steering, the tendency to overcompensate immediately after the 

danger has passed could again result in loss of control. 

In addition to degrading safety, road deterioration can be costly from a maintenance standpoint. Although 

surface mining equipment is designed to accept considerable abuse, its life can be increased if rough handling is kept to a 

minimum. The wear on virtually every component is increased significantly when a vehicle travels rapidly over a rough 

surface. If the vehicle must constantly brake to negotiate poor areas, unnecessary lining wear occurs as well. 

When machinery must operate in dusty areas, the maintenance problems are compounded. Dust may infiltrate 

brakes, air filters. hydraulic lifts, and other critical components. The abrasive effect of this fine material is apt to result in 

frequent and costly cleaning or replacement of these items. 

Essentially, the items related to deterioration of road surfaces are weather, haulage vehicles consistently 

following a similar path in the haulage lane. and spillage. Because these factors are definable, road maintenance should 

begin with an intensive effort to incorporate preventive rather than corrective procedures. 

Roadside ditches and culverts should be periodically inspected and cleaned to insure that no obstructions are 

present. If not cleared, the drainage facilities may overflow in wet weather and cause erosion of the road surface or 

saturation of subbase materials. Maintenance crews equipped with hand tools or machinery such as dozers, loaders, and 

scrapers should be deployed at predetermined intervals to see that all ditch flow lines are free of debris. 

If heavy haulage vehicles continue to use the same path in their respective haulage lanes, the concentration of 

load will eventually create ruts or furrows. To prevent this condition, mine operators should encourage drivers to use 

different areas of the haulage lane. 

Spillage of material from overloaded haulage vehicles is a significant problem at many mines. If spillage is not 

prevented or if the material is allowed en remain on the haulage route, unnecessary bumps or mounds will exist. 

Therefore, every effort must be made at the loading point to prevent equipment from being heaped beyond the limit that 

can be held within the containing vessel. 

During periods of dry weather, or in consistently dry environments, dust may become a problem, especially on 

gravel or crushed stone surfaces. To alleviate this situation, water trucks fitted with special sprinkler systems should be 

employed. If dust problems are severe, the operator should consider applying chemical additives. The incorporation of 

chloride salts with gravel or crushed stone surfaces will enhance moisture retention and eliminate the need for frequent 

road wetting. 

Adherence to the preventive measures discussed can significantly reduce haulage road maintenance problems. 

However, they are not a complete solution. Abnormal surface conditions will occur periodically that require additional 

road maintenance procedures. 

On more permanent surfaces such as asphaltic concrete, surface depressions should be corrected with asphaltic 

patches and either hand tamped or rolled into place. When severe, depressions occur on well packed gravel surfaces, the 

surrounding area should be scarified, filled, and recompacted to an even consistency. 

A motor grader should be used continually to maintain cross slopes, remove spills, and to fill and smooth surface 

depressions as they occur. Whenever the motor grader is used, care must be taken to avoid pushing waste into drainage 
Page 39 of 49 

facilities and the protective faces of safety berms. Accumulated material from the procedure should be removed to 

specially designated areas. 

Ice and snow, whenever they occur, must be completely removed from the haulageway using a motor grader or 

other appropriate equipment. Special attention to the removal of snow and ice is required on asphaltic concrete and other 

smooth surfaces. The close knit texture of these materials make them susceptible to rapid glazing in freezing weather. 

Consequently, they become slick and a definite hazard to vehicle controllability. Measures such as salting or cindering 

must be implemented immediately under these conditions. 

All areas where loose material is employed to increase rolling resistance and vehicle retardation (escape lanes, 

median berms) should be periodically checked for loose consistency. If these areas become compacted, a bulldozer 

equipped with scarifying equipment should be used to break the surface. 

VEHICLE MAINTENANCE CRITERIA

Mine haulage costs often represent up to 50% of total mining costs and sometimes as much as 25% of the 

overall operating, overhead, and other costs of the entire mining operation.13 An item of this magnitude deserves, and 

generally gets, the major share of maintenance attention. 

Most mining companies generally provide for regular, extensive maintenance inspections of their haulage 

vehicles. Some require daily inspection of such things as system pressures and integrity, tire pressure., fluid levels, 

electrical system continuity, belt tension, etc. Periodic maintenance (daily, weekly, or by hours of operation) is done to 

replace filters, change oil, grease fittings, clean air filters and breathers, clean and fill batteries, etc. Periodic inspection is 

required for brake systems pressure, brake linings, wheel bearings, cab controls and accessories, etc. Repair and 

replacement of components such as engine, transmission, rear end, axle, etc., is performed as required. Many companies 

require the truck drivers to file daily reports on vehicle condition. An example of a maintenance checklist is shown in the 

appendix. 

During maintenance checks, special attention should be given to all brake system components to see that they 

are properly adjusted to manufacturer's specifications. A vehicle with improperly maintained service brakes, or pressure 

leakage in the brake components, which causes activation of the emergency brake system, could result in unequal brake 

application and excessive heating of one drum. Because ignition of brake system components and flame propagation to 

other truck areas is not uncommon, fire extinguishers have become standard equipment. In addition, improper 

adjustment of one or more linings places total dependence on the others. If uncorrected, the brakes that are functioning 

properly will experience excessive and unnecessary wear. 

Although this checklist adequately covers those maintenance items that are to be checked on a 500 hour 

operating cycle, a daily log should be kept for each piece of equipment. This log book serves to record any difficulties or 

equipment anomalies experienced by each driver. Items that require repair or adjustment should be noted in the log 

book for the review of the next driver. If the maintenance item is of sufficient magnitude to affect the operating integrity 

of the equipment, a notation should be made in the log, and a notification filed with the maintenance foreman. Through 

this procedure, an operator starting the shift is made aware of the condition of the equipment and can check to see that 

repairs have been performed. After repairing any equipment malfunctions, the mechanic or electrician performing the 

work should be required to initial the log entry, and file an independent report to his foreman with a copy to the 

production foreman, if applicable. At the end of a specified period (1 to 2 weeks), the maintenance foreman should be 

required to review equipment log books to familiarize himself with minor problems being experienced by the operators. 

Log pages should be signed, dated, and filed within a master log kept for each piece of equipment. 

Any equipment maintenance program must be governed by the individual operation. The foregoing example 

indicates how the responsibility for equipment maintenance can be distributed to guarantee that adequate checks are 

conducted and responsive actions are taken. However, the ultimate responsibility for safe day to day operation of 

haulage equipment depends on the equipment operator. Since any deficiencies will affect safety, the driver should 

personally insure that his machinery functions properly before beginning work. 

Every mining company should initiate a program to educate drivers in the performance of preoperational 

equipment checks. For most types of haulage equipment, a preoperational check will require no more than 15 to 20 

minutes prior to each work shift. The preoperational check of machine components by the driver will be limited to items 

that are critical to safe operation, and the minimal time expenditure will be compensated by safer vehicle operation. 

A general indication of the manner in which a driver's maintenance program can be conducted is delineated by 

SAE recommended practice J153. However, the procedures set forth therein do not encompass the numerous component 

differences inherent to various types of large haulage vehicles. The precise manner in which preoperational checks should 

be conducted for each equipment type can be established through the manufacturer and maintenance foreman. 
Page 40 of 49 

Following is a list of items that should be considered essential to an effective preoperational safety check. This 

list may or may not apply to specific equipment types and is not entirely comprehensive. However, it does illustrate a 

majority of the primary steps required. 

I. Vehicle at rest--parking brakes engaged, wheels blocked 

A. Inspect visible body and chassis components for damage, integrity, and operation where 

applicable 

1. Windows 

2. Mirrors 

3. Wipers 

4. Lights (brake, parking, service drive, backup, and, turn) 

5. Doors (cab and compartment access) 

6. Guards (component shrouds, electric cable insulation. etc.) 

7. Wheels and tires (tread, rock ejectors, lock rings, mounting lugs, and tire pressure) 

8. Steering (control arms and stabilizer bars) 

9. Suspension (shock and spring mounts) 

10. Control lines (hydraulic, pneumatic, mechanical cables, and electric cables) 

11. Air tank moisture relief valves 

12. Connections at dynamic brake grids 

13. Face of engine radiator core 

14. Seat and seatbelt mounts 

B. Check all accessible reservoirs for proper fluid levels 

1. Brake 

2. Steering 

3. Fuel 

4. Radiator 

5. Engine lubricant 

6. Hydraulic retarder 

7. Transmission 

8. Batteries 

C. Clean cab of all debris and secure tools., fire extinguisher, roadside flares. etc. 

II. Engine running, transmission in neutral, parking brake engaged, wheels blocked 

A. Inspect visible chassis components for leaks 

1. Control lines (hydraulic, pneumatic, and electrical) 

2. Air tanks 

3. Hydraulic pumps 

4. Air compressors 

5. Exhaust transfer pipes 

6. Coolant lines 

7. Radiator(s) 

8. Dynamic braking grid blower 

B. Check operation of in cab gages and controls 

1. Temperature (oil and water) 
Page 41 of 49 

2. Pressure (air and hydraulic) 

3. Tachometer 

4. Airflow restriction indicators 

5. Ammeter 

6. Hydraulic servoacutators 

7. Accelerator 

8. Retarder 

9. Service brake 

10. Road condition switch 

11. All system engagement indicator lights 

12. Steering 

13. Horn 

14. Backup warning 

15. Engine shutdown 

16. Emergency engine shutdown 

17. Ground fault breaker 

III. Vehicle in motion on level surface at low speed 

A. Check for proper operation of primary controls 

1. Steering 

a. Under power 

b. Engine off to insure integrity of emergency assist 

2. Braking 

a. Retarder: 

b. Service brakes under power 

c. Service brakes with engine off 

3. Transmission 

B. Listen for unusual noises 

RUNAWAY VEHICLE SAFETY PROVISIONS

The large size of haulage vehicles precludes use of conventional vehicle arresting or impact attenuation devices 

to stop a runaway. In haulage operations with adverse grades, retarder failure has resulted in loss of life and substantial 

property damage. Some safety provisions should be incorporated into haulage road design to guard against the 

consequences of runaway vehicles. 

The primary design consideration for runaway vehicle protection is the required spacing between protective 

provisions. If a runaway situation should occur, the driver must encounter a safety provision before his truck is travelling 

too fast to manoeuvre. The top speed at which the driver can maintain control (steering) of a particular vehicle is 

designated "maximum permissible vehicle speed." A single velocity could have been identified as the recommended 

maximum for all safety provision entrances. However, the ultimate speed at which a driver can still maintain steerability 

and guidance of his vehicle varies according to manufacturer's design, road condition, and operator's experience. The 

speed to accept as a guiding criterion for the spacing of runaway protective devices can best be determined through a 

cooperative effort between the operators and management at each mine site. 

On tables 13 and 14, distances between runaway truck safety provisions are given for various road grades and 

maximum permissible velocities or terminal vehicle velocities. They apply to any type of runaway protection device, and 

delineate the distance in feet required between safety measure entrances for a truck to avoid exceeding the maximum 

permissible vehicle speed. 
Page 42 of 49 

The tables illustrate differences in spacing requirements as they are affected by initial downgrade speed at the 

time total brake system failure occurs. Initial truck speed at loss of braking and retardation was assumed to be 20 mph 

for table 13 and 10 mph for table 14. Although operating speeds may vary considerably depending on policies at each 

mine, 10 and 20 mph initial velocities constitute a sufficient range for the grades given. 

 

 

The following sections discuss two types of runaway vehicle safety provisions. Their spacing should be 

established in conformance with the recommendations set forth in the preceding discussion. 

Runaway Vehicle Collision Berms 

As research into berms and runaway truck protection progressed within this project, an innovative design from 

Australia was investigated and found to have considerable merit. Utilizing an intermittent triangular berm constructed in 

the middle of a haulage road, Australian mining companies have been able to almost eliminate problems with runaway 

vehicles. 
Page 43 of 49 

These runaway vehicle collision berms are constructed of non-consolidated screened fines and placed at crucial 

points within the haulage operation. If the brakes and retarder of a vehicle fail during operation, the driver aligns the 

vehicle so that it straddles the collision berms. and rides the vehicle to a stop. This type of median design is actually a 

simplified form of vehicle arresting device. The most critical design aspects of this type of berm are the spacing between 

the berm sections and the height of the berm in relation to the undercarriage of the vehicle. The spacing between berms 

must be sufficient to allow a runaway vehicle to align itself with the berm before impact. If properly aligned, the vehicle 

will shear off that portion of the berm above the undercarriage, expending energy through momentum transfer, rolling 

resistance, and frictional action until stopped. If improperly aligned, the vehicle could overturn. Accordingly, adequate 

space between berms must be maintained to allow the driver time to position his vehicle with respect to the berm. 

Typical sections of these berms with sizing and spacing criteria are shown in figures 26 and 27. 

A table is provided with figure 26 to show approximate sizing for various tonnage vehicles. Ranges are given 

rather than specific dimensions since each berm design must be governed by the height of undercarriage and wheel track 

of the vehicle for which the berm is designed. Where vehicles of different sizes are operating concurrently on a haulage 

road, the berm should be sized primarily according to the wheel track of the larger vehicle. since smaller vehicles will be 

stopped on the "entrance ramp" to the berm. The simplicity and economic attractiveness of this design lends itself well to 

practically any haulage operation. For haulage roads with less severe grades and associated fewer problems with 

runaway vehicles, collision berms may be located in critical areas only. 

A prerequisite to the use of berms is the ability to economically build a road of sufficient width to accommodate 

them. Another factor is the necessity of using screened fines in the construction. Depending upon the type of operation, 

a mobile crusher could be used to facilitate the construction and maintenance of the berm.

Median berms are most effective at reduced vehicle velocities. The drivers of haulage vehicles must be instructed 

in the proper use of the median berm and taught to rely upon it as a first line emergency manoeuvre and before the 

vehicle has accelerated beyond a reasonable speed. 

At one mine site in Australia with extremely severe grades (8% to 12%), these median collision berms have been 

in use for 3 years. Within that time, runaways have occurred on an average of once every 2 to 3 months. In all cases 

except one, the vehicles were safely stopped with usually only minor dam.. age to the undercarriage. In the one incident 

where the vehicle was not stopped, the berm slowed the truck to the point where the driver could safely steer into the 

cut side of the bench. 
Page 44 of 49 

Prior to incorporating this device in temperate climate areas, careful consideration must be given to required 

maintenance. The majority of surface mining States experience freeze conditions during winter months. If collision berms 

are not protected from solidification in these periods, a vehicle could be severely damaged in an encounter. If climate at 

the mine site has this potential, collision berms must be constantly checked, and where freezing occurs, the berms must 

be agitated to achieve their former unconsolidation. In cases where freezing and/or excessive rainfall is a constant 

problem, a protective covering of material such as polyethylene or an alternate safety provision is recommended. 

Escape Lanes 

Escape lanes for control of runaway vehicles have been used extensively on mountain highways in the United 

States. Relatively simple in design and successful in application, escape lanes are relied upon by highway designers for 

use on long, sustained grades. 

Escape lanes have good potential for intercepting and stopping runaway haulage vehicles. However. they may be 

expensive to construct and maintains depending on site conditions. Costs incurred in construction are primarily attributed 

to bench excavation and roadbed preparation. 

Emergency escape lanes have three basic areas of design and construction: entrance areas. deceleration areas. 

and stopping areas. Each of these will be discussed separately. 

Entrance

The entrance from the main haulageway is perhaps the most important design and construction consideration of 

an escape lane. Entrance areas must be spaced according to maximum permissible vehicle speed and percent grade of 

the main haulage road. Included within the entrance area are vertical curve transitions., horizontal curve development 

(including super elevation's), and lane development. Care must be taken that any horizontal curve can be negotiated by 

the runaway vehicle. Table 15 lists maximum horizontal curves as related to vehicle entrance speeds and super 

elevation's. Super elevations less than 0.06 fpf or greater than 0.10 fpf are not recommended due to difficulties with 

curve development and drainage. 

Another important element of proper entrance design is lane width. The lane must be wide enough to 

accommodate the vehicle but not so wide as to require excessive construction effort. Recommended minimum lane 

widths for escape lanes are presented in table 16 for various vehicle categories. 

Deceleration

The major contribution of an escape lane to deceleration of a runaway. vehicle is that of reverse grade. The 

greater the reverse grade of an escape~ way, the less length required. Table 17 relates escapeway lengths to vehicle 

entrance velocities and percent grade of the escape lane. The formula used in computing escapeway length is 
Page 45 of 49 

It is important to note that a coefficient of rolling resistance of 0.2 or 400 ppt (pounds per ton) was used to 

compute the distances. This value is the resistance offered by an unconsolidated surface material such as sand or loose 

earth. Escape lanes should not be a continuation of the main haulage road, and all normal road maintenance should 

cease at the end of the entrance area. Escape lanes are most functional when rolling resistance is high. Poorly 

compacted, deep, loose, granular materials are best suited for roadbed use in deceleration areas since these materials 

tend to retard vehicle movement. It should also be noted that distances given in table 17 are to be applied from the end 

of the entrance area; that is, at the end of the horizontal and vertical curves. Also, surface material characteristic of that 

used on the main haulage road should be employed to the end of these curves. 

In this manner, a safe transition from hard to loose surface can be achieved. 

Stopping

After a vehicle has been slowed through the deceleration grade and high rolling resistance roadbed, it becomes 

necessary to stop the vehicle and prevent its coasting back down the escape lane. Approximately three quarters of the 

way up the escape lane, provisions for stopping the vehicle should begin. Stopping or arresting techniques include the 

following: 

A level section of roadway at the end of the escape lane. 

Median Berm. Amedian berm., constructed on the escape lane. is one of the most efficient means for vehicle 

arrest. Using the same basis for design as that presented in the previous section, median berms are well suited for use in 

conjunction with escape lanes. 

Sand or Gravel or Mud Pits. After vehicle has been slowed down on the escape lane, a deep sand, gravel, or mud 

fitted pit will cause the wheels to become stuck., thus prohibiting further movement until assisted by another vehicle. 

This concept is very effective if properly maintained. 

Road Bumps. Road bumps, whether constructed by excavating trenches or establishing mounds across the lane, 

retard vehicle movement by trapping in "designed ruts." Mounds or bumps must be thoroughly compacted to insure 

integrity under the weight of a truck. 

Manual Steering. It is not practical or possible to do any of the foregoing, or if the runaway does not reach the 

"stopping area," when the truck comes to rest the driver should be trained to either engage the transmission in a "ParW' 

position, or set an emergency brake (if usable), or engage the transmission in the lowest possible gear and turn the 

wheels away from the escape lane berm. 

Figures 28 30 depict typical plan, profile, and section views of an emergency escape lane. 
Page 46 of 49 

CONCLUSIONS

Surface mining, regardless of mineral commodity being sought through its inception, is a highly competitive 

business and, like any other business, a beneficial cost to profit ratio must be maintained. It is important to insure that 

cost efficiency does not impinge upon the intangible aspects of mining such as operator safety and proper equipment 

utilization. From the sites selected as being representative of typical mining operations, it became apparent that in many 

instances haulage road construction is not considerate of operator safety; not as a result of disregard, but rather a lack of 

awareness of correct design principles. The most obvious disparity between existing haulage road construction practices 

and criteria recommended for safety lies in the areas of alignment and drainage. 

Sustained haulage road gradients at many eastern surface mines exceed the 10% maximum stipulated for safety 

in the Haulage Road Design Study. In most cases, the rationale for constructing a greater gradient is obvious to keep 
Page 47 of 49 

haulage distances as short as possible through steep mountainous terrain. Superelevation on curves, tangent roadway 

cross slopes, and vertical curves at grade crests are other design factors seldom applied. 

In general, application of adequate roadway drainage provisions are also lacking. Severely scoured and rutted 

road surfaces, roadside ditches eroded to excessive depths, water filled depressions in the roadway, and unstable or 

slippery road segments are common sights throughout the eastern surface mining region. 

As illustrated by table 18, costs associated with haulage road construction to remedy safety hazards such as 

those mentioned can be considerable. At the surface coal mine sites. for example, construction expenditures exceed 

$200,000. It must be noted, however, that the haulage roads of each of the surface coal mines were subjected to major 

design revisions; thus, costs far exceeded those for the quarry operation where only minor revisions to existing roadway 

were made. Also, the costs associated with study site roads were accrued as a result of changes to existing conditions. If 

the designs recommended herein had been incorporated during construction, the cost of the proposed roadways would 

have been little more than that of the roadways now being used. Of course, it would be unrealistic to assume that this 

situation will prevail at all mine sites; however, it does apply in a majority of cases.

The benefits to be derived from safe haulage road design and construction quite often lie unseen as the 

intangible factors of reduced accidents and injuries. However, in many cases, the incorporation of correct design 

principles can increase mine productivity. Table 18 illustrates this point for sites 1 and 3. Haulage road revisions at both 

of these mines will increase haulage rates and., in doing so, reduce operating costs. Moreover, increased haulage road 

safety will definitely reduce accident potential. If, for example, this increased level of safety prevents one accident that 

would have destroyed a $150,000, 50 ton haulage truck, road construction costs would be almost offset at the mining 

operations considered during this study. 

Perhaps the most relevant point to be made concerning safe haulage road design is that regardless of site 

conditions or economics. safety provisions can and must be incorporated. For example, on excessive gradients that 

cannot be feasibly altered, collision berms or escape lanes can be provided, through minor earthwork, to arrest runaway 

vehicles. Little time is required for a dozer to cut roadside ditches and trucks to provide dumped rock where erosion 

control is necessary. The creation of curve superelevation and tangent cross slope are always possible at little cost. If 

recommended road surface materials cannot be obtained, the best materials available can be applied together with a 

frequent road maintenance schedule to insure consistency and integrity. 
Page 48 of 49 

Appendix
Page 49 of 49 
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Title: Information Circular 8758 

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