Implications of Road Freight Vehicle Weight Legislation in South Africa


1. Introduction  

In South Africa there has been protracted debate about the rapid increases in the volumes of road freight and the effects on the roads of the country. There is widespread deterioration that is particularly noticeable on the major rural roads that are used for bulk mineral and agricultural commodities.

The expansion of road haulage is in part due to the policy decisions taken in 1980s to deregulate road freight transport and to permit open competition between road haulage and the state-owned railways. The road hauliers targeted high value rail cargoes over distances of up to 500 kilometres on the major corridors and bulk commodities on shorter hauls between point of production and processing. In addition there has been very rapid expansion of shorter-haul distribution traffic around and within urban areas until the estimated volume of road transport is about 1.4 billion tons per year.

The situation with road condition has been aggravated by the fact that over the last 20 years there has been a reprioritisation of government funding which has seen a reduction in the amounts available for road maintenance and rehabilitation, to the point where the backlog is estimated to be somewhere between R20 and R40 billion.

An aspect of the usage of road usage  that is frequently quoted as a major factor contributing to road deterioration is the overloading of freight vehicles beyond the Legal Axle Mass Load (LAM) prescribed in the Road Traffic Act. The lack of a holistic matrix of statistics makes this contention difficult to prove or disprove, but as shown in later sections of this paper the contention may not be correct.

The purpose of this paper is to document  some of the known facts about the situation, to identify various other frequently ignored factors that have contributed to the demise of the roads and to provide a basis for evaluation of appropriate strategies to improve the sustainability of the road transport industries in Southern Africa. 

2. Road Usage and Wear

Roads are built to different standards and depending on the design and construction, have totally different costs and usable life. It is an accepted fact that roads do not last forever and must be constantly maintained as they are “consumables” in the overall provision of the transport system of the country. A variety of factors can have impact on the usable life of road pavements as discussed in the following sections.

Road authorities and governmental agencies in most countries monitor a range of aspects of road traffic and transport that are the major contributory factors  causing  accelerated deterioration of road pavements.  In South Africa there are current problems with road deterioration, and it is safe to say that  the  overall “rate of consumption or usage” of the pavements is greater than the ability of the authorities to rehabilitate the roads, so as to maintain them in satisfactory condition.

It is important to identify and quantify the factors that have contributed present conditions, as the present situation is unsustainable and there is urgent need to address the problem which is increasing exponentially with time as remedial actions are delayed.

In the  following sections of this report the various factors that influence the “usage” of roads are described, as well as the  interactions between the unsustainable road freight transport system and the other modes of land transport.

The major factors that have contributed to the greatly increased  usage of roads over the past 20 years can be readily identified and described.

2.1 Numbers of Vehicles

During the past 40 years there has been a steady increase in the use of road haulage and in the past 20 years since the deregulation of the road freight industry there has been a massive surge in the numbers of road freight vehicles all over the country. The volumes on the main road freight corridors have almost doubled in the past 10 years. An example of these increases is shown in the graph of traffic volumes at Mooi River on the N3, below, for the period 2003 – 2009. Traffic volumes are recovering in 2011 after the recessionary dip in 2009-2010.

The current volumes are more than 10 times the traffic flows of heavy goods vehicles contemplated by the road engineers when the N3 national road was designed in the 1950s, and the vehicles are much bigger, faster and impose much higher axle loads.

2.2 Design Standards and Life Expectancy

Roads in South Africa were almost all built for 8200 kg axles, low-speed heavy vehicles, crossply tyres (inflated to about 480kpa), and estimated traffic levels that would give an approximate pavement life of  20 years between major rehabilitation activities.

2.3 Axle Loads

The definitive series of experiments conducted in USA by the AASHTO [American Association of State Highway and Traffic Officials) in the 1970s quantified the understanding that road surfaces are progressively deteriorated [degraded and worn out] by the passage of loaded axles in direct relation to the weight imposed by the wheels on the road surface. The AASHTO experiments showed that increasing axle [wheel] weights caused exponentially progressive damage to the road in relation to increased weight [measured in E80s in South Africa i.e. 80 kN equivalent base axle load standard] (1000 kgs of weight exerts a force of 1kN at sea level): NB: South African literature refers to “mass” not “weight” and for present purposes the terms are used interchangeably.

The impact of an axle on a pavement increases exponentially for every kN over the base axle load standard [the so called fourth power rule, that was established by the abovementioned AASHTO experiments], as shown in the formula below.

F =    (_P)n                                                                  


Where       n  =   relative damage exponent        [Normally 4, but depends on pavement design and condition]

F =    load equivalency factor [80kN is equivalent to 1]

P =    axle load in kN         [NB: In SA 90 kN should technically now be 1]

Road pavements in South Africa have been generally designed to handle an estimated number of vehicles [axles] of standard 80 kN weight over a design life of typically 20 years before they need extensive rehabilitation. The effect of the passage of larger numbers of overloaded vehicles is to deteriorate the road pavements to the point of destruction in much shorter periods of time. The heavier the axleloads the more rapid the deterioration. In extreme cases the passage of one or two greatly overloaded vehicles can do irreparable harm to a pavement due to the load equivalency factors.

The implications of the more rapid wear or deterioration of roads is that roads authorities are required to release funds for road rehabilitation more often, or in greater quantities than would be the case if all axle loads were within the design standards. Failure to repair the roads at the optimum point of the deterioration curve, due to lack of funds, aggravates the funding problem as this accelerates the destruction and increases the rebuilding costs. 

2.4 Life Cycle

It has been conclusively demonstrated that the activities performed to manage the life cycle of the road have a critical influence on the life and costs of the pavement. In South Africa, a large proportion of the major roads were built in the period 1950-1975 and are therefore 40 – 60 years old.

“Design life “is always dependent on the assumption that there will be routine maintenance procedures to obviate the obvious causes of road destruction. In most areas of South Africa, the roads have not been receiving the necessary levels of continued rehabilitation activity required to realise their full life cycle potential. The continual repair and resurfacing that is required to ensure that water is not allowed to destroy the sub-base is a critical activity which when neglected, causes the rapid collapse of the road structure. It is a tribute to the original designers and builders of these roads that they are still usable many years beyond their design life.

2.5 Tyre Characteristics

It must also be noted that the design standards for South African roads were based on the use of cross-ply tyres. There has been a complete change to steel belt radial tyres since the 1980s. The point loading effect of steel radials at 850-1000 kpa is approximately double that of cross-ply tyres at 480 -600 kpa carrying the same load. Modern road designs must therefore base the effects of wheel loading on the use of steel radials. (De Beer, Kannemeyer and Fisher).1  

2.6 Vehicle Dimensions and Weights

The size and weights of road freight vehicles and combinations have important implications for a number of aspects of the transport system, including the following;

–        dimensional specifications (length, height and width),

–        the maximum permissible mass of vehicles (Gross Vehicle Mass (GVM)

–        maximum permissible mass of combinations (Gross Combination Mass (GCM)

–        Legal Axle Mass Loads (LAM) of single, dual and tridem axle groups.

Decisions regarding these aspects of vehicle design and operation affect a range of different issues in the overall transport environment apart from road damage as discussed in later sections of this report.

2.7 Control of Overloading

In the design of pavements there is an assumption that load mass will be controlled and that overloading will be kept to a minimum. Design standards typically apply a safety factor to allow for some overloaded axles.

In many areas of South Africa there is ineffective control of overloading and even on the main corridors such as the N3 which has the most effective overloading controls in the country, the 10 heaviest loads recorded in 2009 were cross-border containers with gross combination mass of approximately 78 tons that had travelled 1000 kms on national routes, before being apprehended. There is no way of knowing how many such loads are moving around the country’s roads.

3. Historical Development of the South African Road Problem

The historical development of the present road problem in South Africa is the direct result of a series of policy decisions of omission and commission taken by government over the 40 year period from 1970 to 2010. The various decisions and their impacts are described in the following sections. 

3.1 Period of Vacillation

In the period 1970-1980 there was increased emphasis on overload control by provinces, using the outdated equipment available to the traffic authorities. The calibration, operation and condition of much of the equipment was not effectively controlled, thereby giving rise to successful appeals and legal action by hauliers against inaccurate, obsolete, weighing equipment. This led to confrontation with traffic authorities and a series of challenges that made prosecution almost impossible. The problem of vehicle overloading was exacerbated by the irresolution of the authorities and the lack of a system of registration and control of road transport operators.

The road authorities did not respond with effective equipment, improved enforcement procedures and control of hauliers so that enforcement by provincial traffic officials became very dilatory [with the possible exception of KwaZulu-Natal].

A further disincentive to traffic officers during this period  was the continual debate with DOT fostered by the road transport industry, throughout the 1980s about proposals to increase permissible maximum axle loads in the interest of economic efficiency. The continued allowance of “tolerances” was seen to be further evidence of irresolution by the authorities.

Why prosecute for overloading if the LAM is going to be increased by the authorities ?

It must be noted that the rapid growth of road transport was at that time still relatively controlled by the terms of the Road Transportation Act, which inhibited the use of road transport for long haul transportation. 

3.2 Increased LAM

The ambivalence of the authorities was made more apparent when legal axle load (LAM) was increased from 8200 kgs to 9000 kgs in 1993, by the Department of Transport. This was done in spite of seven different studies that showed that this would have negative effects on the roads1. It was also noted in the studies that the increase in Legal Axle Mass [LAM] would be of most benefit to rigid vehicles and smaller short-haul combinations, not the long distance hauliers that were the primary motivators of the transport efficiency arguments.

Using the fourth power rule the additional wear introduced by the increased axle weight would amount to a 60% increase in the road loading for the same amount of traffic, if all axles were loaded to the maximum permissible. The impact of the change from 80kN standard to 90kN standard axle load is shown in the graph below.

Load Equivalence of Single Axle Mass Load for 8200 kgs and 9000  kgs

The blue [upper] line represents the load equivalency based on 90 kN per axle and the red [lower] line shows the equivalency based on 80 kN per axle. As shown, the change represents a deliberate official increase of 59% in permissible axle load equivalency.

The decision to increase LAM was taken in spite of the fact that most South African roads and bridges were originally designed for 8200 kg axle loads and are therefore universally under-specified for the 9000 kg axle weight. (Buses and coaches are permitted to operate with 10,200 kgs axle loads). 

3.3 Deregulation

The immediate effect of deregulation of road transport in 1984, was a rapid increase in the numbers of long distance freight hauliers entering the market. The removal of permit restrictions  rapidly led to oversupply and fierce competition for high value rail cargo and industrial bulk haulage. The road freight industry responded by making representations to the authorities for increased carrying capacity for road vehicles.

3.4 Increased Vehicle Dimensions

The increase in the permissible legal axle loads [LAM] was accompanied by further legislation to increase vehicle combination lengths [to 22 metres] and semitrailer length (from 12 to 14 metres), vehicle widths [2.5 to 2.6 metres] and vehicle height [4.1 to 4.3 metres]. The bridge formula was changed to permit the full use of the new dimensions, which permit a 62 ton gross combination weight [65 tons with 5% tolerance].

Then, allegedly at the request of the railways, in a belated attempt to cap the carrying capacity of the new vehicle dimensions, a limit of 56,000 kgs Gross Combination Mass [GCM] was introduced, [unrelated to bridge or axle load limits]. The effect on the biggest long haul combinations of capping the GCM at 56,000 kgs represents a restriction to  8000 kgs per axle for a 7-axle rig. 

3.5 Road-Rail Competition

As predicted by the Research Unit for Transport and Physical Distribution Studies [RTPS] at RAU2 , increasing the legally permissible axle mass loads would increase competition for long haul rail cargo. This is due to the fact that larger road vehicles can transport cargo at lower cost per ton kilometre than smaller vehicles. In fact the combination of deregulation, increased cubic dimensions and increased carrying capacity greatly enhanced the competitiveness of road haulage and caused a rapid expansion of the road transport industry into what was previously high value rail cargo [the extent of the modal switch was originally estimated to amount to about 35%].

This trend was exaggerated by the rapid increase in the manufacture and import of the products of tertiary industries and the fact that a large proportion of industrial and domestic cargo “cubes-out” before reaching maximum weights [in USA 76%]. This means that the increase in vehicle cubic dimensions and the axle loads granted in the 1990s opened possibilities for reduced rates, and aggravated the transfer from rail to road, which has greatly exceeded the predicted  35% of general goods traffic then on rail.

This situation was exacerbated by the deregulation of railways and the policy revision that relieved it  from “public carrier “obligations and committed it as a parastatal monopoly to pursue profit and self sufficiency. This policy led to strategic actions taken by the railways to reduce costs and improve profitability by focusing on profitable operations. These actions included  closure of sidings and stations, scrapping of rolling stock and locos, introducing minimum consignment sizes, and a general withdrawal of services for general and industrial cargo.

In the period from 1983 to the present there has been rapid concentration of railway operations and reduction and scrapping of equipment and facilities; by 2007 the loco fleet has shrunk from 4000-5000 units to about 2300 units [of which about 1800 are believed to be fully operational], the wagon fleet has shrunk from 120 000 units to about 80 000 units. Staff numbers have only shrunk by 50% but the average length of service has dropped by 20 years. During the period the general cargo carried has reduced by more than  50% as shown in the graph below.

Annual Tons on Rail by Freight Category – 1949-2007

The overall demand for general freight transport has increased exponentially since 1980 but the railways has substantially reduced its levels of general cargo hauled (blue line). Overall railway capacity has in fact not expanded over the past fifteen years (red line) whilst the demand for industrial transport has  promoted the growth of road haulage to approximately 180 million tonnes of freight on the major corridors and main provincial routes (green line A-B) .

The number of Heavy Goods Vehicles [HGVs] on most major roads increased by over 100% in the period 1980 to 2005. The combined effect of transfer from rail and the increasing volumes caused by economic growth meant that road haulage has been  increasing at about 8% per annum. This is expected to reduce somewhat in the future and continue at about 4-5% i.e. at levels slightly higher than GDP.

 3.6 Reduced Maintenance

The period of rapid expansion of the road freight haulage industry has accelerated the deterioration of the roads, and this has been greatly exacerbated by the simultaneous reduction of government road maintenance funding and the diversion of the previously dedicated Road Fund derived from fuel taxes to meet other social objectives. In 2010 there is a very serious backlog of road maintenance all over South Africa, estimated by various authorities to be somewhere between R20 – R50 billion.

4. The Economics of Freight Transport

4.1 Incentives to Overload

From the perspective of the road transport operator there are two main issues in relation to the loads on vehicles. Firstly each vehicle or combination has a technical and legal load capacity that dictates the maximum permissible load weight; secondly, the load has to be positioned on the vehicles so as to avoid overloading specific axles and axle groups.

For some commodities the weight is known precisely e.g. pockets of cement, litres of diesel etc, and where the same products are loaded on the same vehicle combinations day after day there is no real reason why the loads cannot be precisely located to comply with the law.

For other commodities and mixtures of commodities the load weight is not precisely known e.g. loads of mixed hardware, and in some cases the load weight can only be estimated at point of loading, such as sugarcane, stone, timber etc.

The loading of vehicles is a daily routine function with the constant need to try to correctly distribute the load weights to comply with the law. The process of loading any transport vehicle with goods of unknown weight and varying dimensions is a challenge whether it be a plane, ship or truck and effective control is only possible with trained and competent staff.

It must be appreciated that failure to achieve the maximum possible [legal] load represents lost revenue to the transport operator so that there is always the tendency to load as close as possible to maximum, even if this sometimes means exceeding the legal limits.

Road freight vehicle specifications are such that the imposition of some extra weight has minimal effect on the operating costs or performance of the vehicle. Increasing the load weight by 10% increases fuel consumption by approximately  1-2 % and increases wear and tear by an almost imperceptible amount.

If the operator is achieving a 10% return on his capital, the successful transport of a 10% overload without incurring penalties contributes 100% of extra revenue for the load.  As an example: for a 30-ton load of goods to be transported 500 kms at a rate of R10.00 per kilometre the revenue is R5000 [R166.60 per ton]. If 10% of the charge rate can be assumed to be mark-up the profit would be approximately R500.

If the load was increased to 33 tons and the cost remained at R5000, the cost per ton reduces to R 151.50 or, [in practise] the operator still charges R166.60 per ton and the revenue therefore increase to R5500, thereby doubling the profit for the load to R 1000.

If the operating cost increased by 4%, the 10% overload would still yield excess profits, as costs would rise to R 5200 and revenue to R5500, yielding increased profit of R 500 + R300 = R 800.

From the operator perspective; an interlink combination with 7 axles has a legal GCM of 56,000 kgs and a payload of about 38.0 tons; but it can be shown that 6 axles at 9000 kgs and one axle at 7700 kgs gives a GCM of 61,700 kgs and a potential payload of 43.7 tons [which amounts to a 15% overload] without exceeding the 9000 kgs axle limits. It is therefore argued that the current 56,000 kgs regulatory GCM limit cannot be shown to be solely motivated for protecting the roads or the bridges. In fact the 56,000 kgs limit is a reduction of LAM to 8000 kgs and is therefore obviously not related to control of road damage when the authorities have deliberately increased LAM to 9000 kgs [ + 5% tolerance = 9450 kgs] .

For the operator there is always the risk of apprehension for overloading. The actual risk can be shown to have 3 components; the risk of being weighed [not all vehicles are weighed]; risk of being fined [penalties are only imposed if weight exceeds tolerance levels] and; the amount of the penalty or fine. It is apparent that if the chances of apprehension for overloading are low, there will be a marked tendency for operators to take chances as the risk factor for any given load can be shown to be:

[(a) Risk of being apprehended x (b) risk of being fined x (c) R   amount of the fine] 

If (a) 10% x (b) 50% = 0.01% x (c) R 1000 then the risk per load is R50.00, which is not likely to be serious deterrent. It can also be demonstrated that where a transporter is pressured by excessive competition to quote rates at or below the cost of operating, the amount of revenue earned from overloading is often the factor that determines survival of the firm.

4.2 Road Condition and Operating Costs

The reducing quality of the road pavements is a major cause for concern to operators as badly maintained and potholed roads are having a significantly negative effect on operating costs, accidents and reduced operating efficiency.

In particular the damage to tyres and suspension is greatly increased by the presence of potholes, cracking, eroded shoulders, and corrugations. The steel radial tyre is primarily designed for operation on good smooth surfaced macadam roads with no sharp edges that can damage sidewalls and minimal high impact potholes and corrugations. The negative impact on chassis, suspension, steering  and superstructure of freight vehicles fitted with radial tyres, operating on rough roads,  causes breakage and increased costs and reduced safety and component life.

4.3 Road Provision and User Cost Recovery

As noted in previous sections of this paper, roads are consumables in the long term provision of transport and as such the cost of providing roads should be included in the cost of the transport service provided to the user. The authorities that provide the roads as a “public good” are faced with the problem of “road user cost recovery”. The allocation of costs is complicated by  the fact that the costs of various  operations performed in different time periods for all sections of contiguous roads are generally borne by various authorities. There is some difficulty in firstly, calculating the actual cost of the road usage for specific periods and secondly to devise an accurate apportionment of the costs to specific users.

In South Africa, many studies of road costs and user recovery have been performed by various teams of researchers , as noted in the bibliography to this paper. These include a study for the Department of Transport in 1989, a widely quoted  benchmark study of road costs and apportionment to heavy vehicle categories performed by Prof. P W Jordaan in 1995, a study of the full cost of externalities of road vehicles in 1999. Overseas studies by TRRL and World Bank over the same period also underscore the difficulties in devising specific recovery rates.

The complicated calculation of road costs must necessarily include assumptions regarding design characteristics, maintenance regime, and the value of investment in the road pavements and financial  costs of public funds. The costs to the user are usually expressed as  rates per kilometre for different vehicle configurations and assumed GCM, if the recovery of all road costs were averaged to all users the cost would be  10-18% of the overall vehicle operating cost.

Very rough calculations indicate that if additional charges were levied to achieve full recovery of road user costs from heavy goods vehicles it could increase the costs of road haulage by approximately 16%.

It must however be noted that from the perspective of the industrial end user of the road transport services, the imposition of secondary road user cost recovery charges such as  tolls, represent an element of double taxation. This so because the industrial concerns already pay, via the transporter, for a range of taxes and levies  on diesel, vehicles, income, etc.

In the whole debate about road user cost recovery it is relevant to make the final observation that whatever charges are levied on freight transport do get passed on to industrial users, which deduct the costs from income, thereby transferring the cost back to the government. The net effect is increased cost of goods paid for by consumers.

5. Responsibility for Control of Overloading

It is the legal responsibility of the transporter to ensure that vehicles are not overloaded.  This principle is applied in all modes of transport and is almost fundamental to the occupation of transport operator.

Recent development of the Administrative Adjudication of Road Traffic Offences (AARTO) legislation in South Africa includes proposals to  introduce the sharing of responsibility for overloading between consignor, consignee and transport operator.  This would appear to introduce several difficulties with enforcement, as it must be based on the presumption that the law is equitable regarding the relationship between consignors/consignees and transporters for all loads, under all circumstances, if the legal principle is to hold.  In practice there are so many different circumstances under which goods are transported that it is virtually impossible for a consignor or a consignee to be held responsible, and it is unlikely that the principle will be accepted without vigorous legal defences.

Many transport circumstances that are everyday occurrences make such allocation of responsibility almost impossible, such as divided loads, loads of mixed goods of unknown weight, consignments that are split between several consignees and in almost all circumstances the consignee and consignors defence would stand if it can be proven that the goods had not being weighed on a fully assized weighbridge.

In addition, enforcement would be dependent on proving that the consignor or the consignee [or his agent] was competent, capable and had in fact attempted to establish the legal payload of the vehicle concerned.  As the process of establishing the legal payload for multiple vehicle combinations is a very complex set of calculations, it is highly unlikely that a consignee could under most circumstances be forced to accept liability.

In several industries such as sugar milling, coal deliveries to power stations, and timber deliveries to mills and export chipping plants, programmes have been introduced to induce consignees to refuse to unload overloaded vehicles. The general premise for such programmes is that overloading of vehicles is deleterious to the roads and that the consignee may at some future time be held liable in terms of AARTO and is therefore entitled at the present time to refuse to unload vehicles which are deemed to be overloaded. The standards are usually defined in relation to the category into which the vehicles have been classified, not by calculation of individual vehicle capabilities. If this process were to be tested in law, there is a danger that a few simple calculations are likely to prove that the maximum load calculation being used for the programme is contestable due to the lack of accurate measurement of the specific vehicles in the combinations.

In addition, some of the load limitations included in the programmes include various aspects of the Road Traffic Act which have no relationship to the axle mass load, for example tractor engine power to mass ratio, proportional distribution of gross mass onto the steering axle, and the ratio between drive axle mass and the gross combination mass.

One of the potentially negative results of broad-spectrum application of theoretical maximum load mass is that the general tendency is to enforce under-loading by carriers to avoid time wastage.  Forced, or induced, under-loading increases the cost per ton of product delivered, increases the amount of fuel used and increases the need for additional vehicles to move the same tonnage. 

6. Voluntary Compliance

There is a prevalent opinion amongst both road freight operators and some road authorities that the allegation that overloading is a primary cause of road deterioration is incorrect, and that the major problem is misallocation of road taxation and reduced funding by government for road maintenance and rehabilitation, relative to current levels of road usage.

It is contended that there is in fact a high level of voluntary compliance with the legal axle mass loads and that the largest proportion of operators are responsibly aware of their duty to protect the roads. This position is reinforced by analysis of 185,544 loads weighed in KZN in 2006, as shown in the table and graph below.

Vehicle Weighing Data by Vehicle Configuration  (KZN 2006)

Source: Annual Report Overloading Control – KZN RTI – CSIR

In the above table the vehicle load data have been arranged in an approximately ascending order of numbers of axles and vehicle /combination carrying capacity. In the right hand column the maximum-recorded mass by vehicle category is divided by the number of axles to give an indication of the average axle loading for the heaviest axles in each category. The average axle weights of each category were not shown in the annual report and this information has not been supplied in the 2008 and 2009 reports.

In the graph below, the data is ranged from smaller to larger vehicle combinations and the average maximum axle load is plotted for each vehicle axle category [dark blue].

As shown above, for combinations with 6 axles or more, the average of the maximum recorded axle loads is below the 9000 kgs line [red]. The average axle loads are not reported but must logically be lower than the maximum loads shown in the above graph. Based on this analysis, the allegations that overloading is the major cause of road damage are not supported.

Analysis of the overloaded vehicles shows that 18% of vehicles were overloaded beyond the 56 ton GCM limit, but by approximately 3% of Gross Combination Mass (GCM), and are therefore generally well below the 9000kgs legal axle mass load.

From the above analysis it can be said that with effective overloading control, such as is the case in KZN, and the normal level of compliance by operators , the main cause of road deterioration not the fault of overloaded vehicles but is the result of deliberate transport policy decisions that have caused  large increases in road transport, combined with reduction of maintenance funding by the authorities and the deliberate increase in permissible legal axle mass loads [LAM].

There is an ever present temptation for operators to increase the loads on vehicles for the reasons described in previous sections of the report. It must therefore be conceded that there are operators that consistently overload by small amounts and others that deliberately ignore the authorities and try to bypass the control process with excessive overloads. This means that  irrespective of all initiatives to achieve voluntary compliance there will still be the need for effective monitoring, control and enforcement of the legal permissible mass of road freight vehicles.

The current situation regarding overloading control is not satisfactory in most parts of  South Africa as described in the following section.
7. Enforcement of Legal Load Standards

7.1 Weighbridges Operated by Traffic Officers

In all countries of the SADC / COMESA region the enforcement authorities for overloading control are either the traffic police or the police. The control of overloading in South Africa is the responsibility of the Road Traffic Inspectorates of the provincial governments [for provincial roads], municipal traffic police [for some of the larger cities] and on some national roads, and the toll road concessionaires.

In South Africa some weighbridges are operated by private-public-partnerships with the private  sector companies providing staff to perform the weighing and administrative functions and the officials handling the issue of enforcement documents.  This has been particularly effective where toll road concessionaires have been given control of the weighbridge operations.

The effectiveness of the overload control systems is highly variable by region, with widespread under-funding of staffing, vehicles and equipment so that the numbers of vehicles weighed is in many areas totally inadequate to exert effective control of operators. The major problems with the overloading control systems are:

  1. Insufficient trained traffic officers to cover extended periods of 24-hour weighbridge operation.
  2. General unwillingness of traffic officers to work shifts around the clock.
  3. Lack of funding at most provincial departments and agencies for adequate staffing, training, motor vehicle operating costs and back-up equipment.
  4. Lack of fully integrated data collection and management systems in many areas, resulting in ineffective record keeping and reporting.
  5. Lack of a properly designed national operator licensing system with a complete operator register through which to exert enforcement.
  6. Lack of detention facilities in many areas to enable impounding of overloaded vehicles in secure areas until loads are adjusted. Vehicles are released, thereby effectively cancelling the enforcement process.
  7. Excessive waste of traffic officer time in prosecuting offenders through inefficiencies in the justice system.
  8. General prosecution of drivers, not operators, by all weighbridge officials due the problems described in (e, f, and g) . This nullifies the enforcement process due to the difficulty in tracing drivers, and contributes to widespread abuse of forged licenses and ID documents. Operators remain unscathed by the enforcement process.
  9. Failure by magistrates to impose appropriate levels of penalties and the system’s inability to record, recall and adjust penalties for unpaid offences and continual contraventions. The AARTO system will address some of these issues but is unlikely to be able to keep track of all staff and vehicle transfers in the freight transport industry to link drivers and vehicles to operators in order to monitor operator performance.
  10. Limited management capability in many areas and lack of commercial capability to contend with operator pressures.
  11. In many areas there are suspect liaisons between traffic officials and hauliers leading to corruption and bribery.
  12. Some PPP weighbridge management contracts have failed to ensure management capability and to measure effectiveness of the enforcement process.
  13. At all weighbridges the level of efficiency is reduced due to the fact that overloading enforcement is often regarded as secondary to other traffic officer functions and officers are frequently withdrawn and deployed to other duties during weighbridge operations. Lack of legal authority to stop vehicles then closes the weighbridge down even if clerical staff is on site.
  14. Different levels of admission-of-guilt penalties between provinces and even between weighbridges.


7.2 Private-Public-Partnership Weighbridge Management

With all of the foregoing in mind there is serious motivation to review the effectiveness of the existing system and re-examine the public-private-partnerships (PPP) alternative. The benefits of commercialisation or public-private-partnerships (PPP) in weighbridge operations can be described as follows:

  1. a) Most traffic authorities suffer shortages of qualified staff, with increasing demands for service delivery, besides overloading control; traffic departments are also restricted in their ability to employ additional staff, by budgetary considerations and the rules of the Department of Public Administration.
  2. b) Traffic Officers must necessarily be trained in a wide range of duties as professionals in traffic management, not as clerical and computer system operators, whereas the private sector PPP supplies only the latter functions.
  3. c) Strict performance parameters can be applied to private sector contracts, and responsibility for staff performance relieves Metro Police management of this burden, to focus on their main professional responsibilities.
  4. d) Within the PPP concept the period of employment can be specified and staff levels can be adjusted at the end of any agreed contract period, which is not possible with public sector staff.
  5. e) With PPP contracts the commercial and systems management skills of the private sector company become immediately available to operate the weighbridge as a business unit.
  6. f) The defined monitoring and reporting processes that are an integral part of the PPP contract ensures that there are minimal opportunities for corrupt interactions between weighbridge staff and transport operators.
  7. g) For the private sector PPP operator the issues of insurance for public liability, professional indemnity, employee liability and cash guarantees are easily arranged compared with public sector agencies.
  8. h) For the private sector operation, employment contracts can be tailored to provide for overtime, irregular working hours, shift rotations, backup staffing and job grading systems that reward the key personnel.
  9. i) Provision of maintenance contracts, peripheral and backup equipment, and the provision of security systems such as camera surveillance are more easily arranged by the private sector.
  10. j) The provision of supporting management services by the professional consultants as associates of the PPP entity ensures the standards of the weighbridge operation.
  11. k) Selection, employment and training of the clerical and computer systems staff becomes a function of the contractor.
  12. l) Transport for weighbridge shift staff is a function of the contractor and is included in the terms of contract, thereby relieving the authority of the need for vehicles.
  13. m) The control of site service obligations such as maintenance, weighbridge assizing, computer backups, software upgrades, etc will become part of the defined functionality of the PPP.
  14. n) Weighbridge output is continually enhanced by the motivation provided by the terms of the contract, which should be designed to reward operational efficiency.


Literature References

  1. RTPS-RAU, An Evaluation of Contemporary Research into the  Implications of Increasing the Legal Axle Mass Loads of  Heavy Goods Vehicles in South Africa RTPS ;Rand Afrikaans University – May 1993
  2. RTPS-RAU,  A Marginal Cargo Impact Analysis of Rail Freight in South Africa, RTPS ; Rand Afrikaans University – May 1993
  3. KZN:RTI / CSIR, WEIGHBRIDGE REPORTS   2006,2008 and 2009
  4. CSIR, TRH 11 – Policy on Abnormal Loads in South Africa,  CSIR- Pretoria
  5. CSIR, TRH 8 – Design Standards for Road Pavement Construction in South Africa, CSIR – Pretoria
  6. M De Beer, L Kannemeyer,  C Fisher, Surfacings Based On Actual Tyre /Pavement Contact Stress-In-Motion (Sim) Data In S A CSIR: RP O Box 395 Pretoria
  7. Poree, N.A., A Transport Economic Appraisal of the Overloading of Vehicles on South African Roads – B.C. Floor Ed., Transport Economic Soc.- 1990
  8. Free State Province, Investigation for Placement of Permanent Weighing Stations  – TMT Projects, Dept. Public Works : Free State: Bloemfontein 1997
  9. SARA, Vehicle Dimension and Overloading Control Study, TMT Projects – SARA   :  Durban April 1999
  10. AA of SA, Situation Report on Heavy Vehicle Overloading in South Africa – TMT Projects : Durban May 2000
  11. NP&A, Proposals to Establish PPP Weighbridge Operation at Durban Bayhead Road Weighbridge Durban –  April 2011