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Southern African Freight Transport Institute

    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 and to identify various other frequently ignored factors that have contributed to the demise of the roads and then to examine some of the  problems and options for addressing the situation.

 

 

2. Road Usage and Wear

 

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

 

Roads are built to different standards and depending on the design and construction and therefore  have totally different costs and usable life. Pavements 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 to the 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 financial capability of the authorities to rehabilitate the roads, so as to maintain them in satisfactory condition.

 

It is useful to examine the various factors that influence the “usage” of roads, as well as the interactions between the currently unsustainable road freight transport system and  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 goods  vehicles all over the country. The volumes on the main road freight corridors have trebled 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.

 

 

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 and faster. The reduction from 2007-2009 due to the recession brought some relief but it is likely to be short lived as the economy recovers.

 

2.2 Design Standards and Life Expectancy

Roads in South Africa were almost all built for 8200 kg axle loads, low-speed heavy vehicles, fitted with crossply tyres (inflated to about 480kpa), and estimated traffic levels that would give an approximate pavement life of  20 years between major rehabilitation activities. All of these conditions have been greatly exceeded.

 

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 they 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

                                                                  

                                       (80)

Where                 n  =      relative damage exponent           [Normally about  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 now be 1]

 

Road pavements in South Africa have generally been 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. If there are  numbers of overloaded vehicles the deterioration of the road pavements occurs  over shorter periods of time. The heavier the overloads 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 factor.

 

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 than 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 problem as this accelerates the destruction and increases the rebuilding costs.

 

2.4 Life Cycle

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 the pavement to obviate the conditions that cause road destruction. 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 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 after all this time.

 

2.5 Tyre Characteristics

A further contributory factor to deterioration of the roads is the fact that design standards for South African roads were based on the use of cross-ply tyres. There has been an almost  total switch to steel belt radial tyres since the 1980s.The cross-ply tyres operate at lower pressures (480-500 kpa) and provide a “softer” ride. The point loading effect of steel radials at 850-1000 kpa is approximately double that of cross-ply tyres carrying the same load. Modern road designs must therefore base the effects for provision of  wheel point loading and the impact of reduced footprint on the characteristics 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. The aspects having implications for the cost and efficiency of road  freight transport and the interactions with other modes include the following;

a)         dimensional specifications (length, height and width)i.e. cubic capacity,

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

c)         maximum permissible combination mass (Gross Combination Mass (GCM)

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

(a), determines cubic capacity and (b), (c), and (d) determine the carrying capacity or  “payload”)

 

Regulation of these  aspects of vehicle design and operation affect a range of different issues in the overall transport environment apart from road damage, such as transport costs per unit kilometre, inter-modal competition,  potential for intermodality, and wider issues such as industrial location and export competitiveness.

 

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 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 relatively unsophisticated weighing  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. Almost invariably all charges were laid against the drivers, who were fined relatively small amounts although they were usually not to blame, and the firm paid the fines. There was widespread collusion between hauliers and officials and very few cases against hauliers were successful. 

 

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 notable 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. The attitude became, 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 for long haul transportation without permits.

 

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 59% 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.

 

2.4 Deregulation

Following on the recommendations of the National Transport Policy Study (NTPS) road and rail transport was deregulated by repeal of the Road Transportation Act of 1974 and changes to the mandate of the railways.

 

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 further lobbying for increased carrying capacity for road vehicles to improve revenues.

 

2.3 Increased Vehicle Dimensions

The DOT responded by amending legislation to increase both mass and cubic capacity.

The increase in the permissible legal axle loads [LAM] from 8200 kgs to 9000 kgs 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 (7 x 8000 = 56.000 kgs).

 

2.5 Road-Rail Competition

As predicted by the Research Unit for Transport and Physical Distribution Studies [RTPS] at RAU3, allowing higher legal axle mass loads (LAM) would increase competition for long haul rail cargo by lowering  the cost per ton-km. of road haulage compared to rail. This is due to the fact that  road vehicles with greater cubic and mass carrying capacity can transport cargo at lower cost per unit-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 further 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.

 

The number of Heavy Goods Vehicles [HGVs] on most major roads increased by over 300% in the period 1990 to 2007. The combined effect of transfer from rail and the increasing volumes caused by economic growth meant that road haulage increased by about 8% per annum. The rate of increase  is expected to reduce somewhat in the future and to continue at about 4-5% i.e. at levels slightly higher than GDP. The rate of increase will depend on the ability of the railways to provide services to handle the increasing amounts of bulk commodities on road.

 

2.5 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  

In view of the continued emphasis in the press about overloading it is relevant to assess the perspectives of the transport operators as an indication of the likelihood that overloading can be totally eliminated.

 

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 [ + 2% = 9180 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) Riskof 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 above, 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 there are many users and 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. In addition, other African 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 (without using the fuel tax fund) it could increase the costs of road haulage by approximately 16%, and of course this would be passed on the industrial customers, by the road freight operators..

 

4.4 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.  (The principle has also been included in Dangerous Goods Transport legislation).This would appear to introduce several difficulties with enforcement, as the application of legislation  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 extensive legal defences.

 

Many transport circumstances that are everyday occurrences make the 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, voluntary compliance programmes have been introduced to induce consignees to refuse to unload overloaded vehicles. The general premise for such programmes is 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 bear 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. In several areas carriers have arranged the availability of unloading machines, to enable loads to “legalised” at the mill. The disposal of the overloaded cane dumped on the ground, poses some interesting legal problems as it should theoretically belong to a grower in order to be delivered to a mill.  

 

4.5 Voluntary Compliance

There is a prevalent opinion amongst many road freight operators and some technical experts and 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 were not reported but must logically be lower than the maximum loads shown in the above graph..

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. Based on this analysis, the allegations that overloading is the major cause of road damage are not supported

 

This situation is confirmed by analysis of 64570 vehicle weighings performed at Heidelberg on the N3 between January and July 2010, where the overloaded vehicles amounted to 5% and of those overloaded 21% were within the tolerance levels.

 

From the above analysis it can be said that with effective overloading control, such as is the case along the N3, N4 and other toll roads and the normal level of compliance by operators , the main cause of road deterioration is not overloaded vehicles but is the result of the rapid  increase in the volumes and characteristics of road freight transport, to levels much higher than  the design parameters of the roads, and the simultaneous reduction of maintenance funding by the authorities.

 

            5. Overloading Control

There is however an ever-present temptation for operators to increase the loads on vehicles for the reasons described above. It must therefore be conceded that there are operators that overload inadvertently, others that consistently overload by “affordable” amounts and some that deliberately ignore the regulations and try to bypass the control process with excessive overloads. This means that irrespective of all initiatives to achieve voluntary compliance there will always 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 for the following reasons.

 

 

 

 

5.1 Current Problems

5.1.1Enforcement Agencies

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, the toll concessionaires.

 

The effectiveness of the overload control systems is highly variable by region. In several regions the numbers of weighbridges is totally inadequate to control overloading. In most regions there is under-funding that limits 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 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.
  6. Excessive waste of traffic officer time in prosecuting offenders through inefficiencies in the justice system.
  7. Failure by magistrates to impose appropriate levels of penalties and the system’s inability to adjust penalties for unpaid offences and continual contraventions.
  8. Limited management capability in many areas and lack of commercial capability to contend with operator pressures.
  9. In many areas there are suspect liaisons between traffic officials and hauliers leading to corruption and bribery.
  10. Where PPP weighbridge management contracts have been established there has in the past been failure to ensure management capability, and inadequate control of the operating standards and the levels of charges to the authority.
  11. At PPP 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.
  12. Different levels of admission-of-guilt penalties between provinces and even between weighbridges.
  13. Lack of a properly designed national operator licensing system with a complete operator register through which to exert enforcement that really gets to the right people in the operator firms.


5.1.2 Operator Register and Management System

The basic underlying problem in South Africa (and the region) is the failure to establish the essential elements of an effective operator registration system. As in all modes of transport the registration of operators and the key elements of their operations is the fundamental requirement for effective administration and the maintenance of operating standards. Applicants for Road Transport Operator Licences should meet specific criteria in order to qualify and licences should be revocable under  specific conditions.

 

The system must include (1) an operator register (with full identification of executives and managers) and details the firm. Monthly system  updates will include all offences, payments, summonses etc. ; (2) a register of nominated competent persons at each operating centre; (3) a register of all employed professional drivers (PrDP); (4) a register of all freight vehicles operated by each operator. All registers must be maintained by monthly returns and updates(usually by IT or Fax). The system must be   competently monitored by a professionally designed computer database located at a Freight Management Bureau. The bureau must be professionally managed and  should be established as a PPP with high levels of oversight and responsibility to ensure control of corruption and graft as is endemic in the so many public sector agencies.

 

5.1.3 System Improvements

There are several simple and cost-effective actions that would make a difference to the effectiveness of the enforcement effort. These include the following actions, some of which are dependent on the creation of the operator registration system.

 

a) Detention Facilities

Improved facilities for detention of vehicles and provision of space for load transfer will ensure maximum use of this very effective deterrent .

 

b) Vehicle plating

Legislation should introduce the need for a simple plate on the left hand side of every freight vehicle, giving Name, Operator Number and Address of the Operator and the LAM of each axle. These to be checked and confirmed at each annual COR.

 

c) Operator Notification

The registration system should give periodic feed back to operators as to the record and status in the system, to be defined as a Compliance Rating .

 

d) Warning Notices

Operators with unsatisfactory Compliance Ratings, and outstanding fines  should receive regular warning notices.

 

e) Prosecutor Education

There is a great need for training of court personnel as the intricacies of the Road Traffic Act are generally not well know by prosecutors and magistrates.

 

f) Increased Fine levels for Habitual Offenders

The creation of an effective registration system will enable the application of increased fien levels for habitual offenders as a further deterrent.

 

The introduction of these enhancements to the present system would increase effectiveness and reduce the amount of deliberate avoidance and non-payment of penalties.

 

 

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. P.W. JORDAAN; Aspects of Cost Recovery of Heavy Vehicles on South African Roads

; Spoornet Strategic Management – July 1995

 

4. CSIR; A Quantitative Analysis of the Full Costs Associated with Motor Vehicle Use in South Africa

 

5. WORLD BANK; RoadDeterioration in Developing Countries

World Bank – 1988

 

6. VAN WYK & LOUW INC.; Final Report on the Reassessment of Road-Infrastructure Cost Recovery

Department of Transport – June 1989

 

7. SW ABAYNAYAKA; Tables For Estimating Vehicle Operating Costs on Rural Roads in Developing Countries
G MOROSIUK; Department of the Environment – TRRL

    R ROBINSON Crowthorne, UK 1976

 

 

8.PORÉE  N., WALTERS J.; A Transport Economic Appraisal of the Overloading of Vehicles on South African Roads

Transport Economic Soc. SA – August 1990

 

9.M DE BEER, L KANNEMEYER,; Surfacings Based On Actual Tyre /Pavement Contact

C FISHER; Stress-In-Motion (Sim) Data In S A

CSIR :Roads and Transport Technology,

CSIR-P O Box 395 Pretoria

 

10. CSIR: KZN RTI; Annual Reports: Overload Control2006/2008/2009

CSIR and Kwa Zulu-Natal Department of Transport

 

11.DEPARTMENT OF TRANSPORT National Road Traffic Act No. 93 of 1996
Government Printer – Pretoria 1996