Seven axles or two, overloading is a problem affecting all vehicle sizes. The trick, to avoid prosecution, is to understand load mass distribution across axle groups.

The global recession is affecting transport operators around the world and South Africa’s road freight industry has really taken a knock in recent months. With resources at a stretch, it has been reported by weighbridge officials that a sudden spike in overloading has occurred, albeit with fewer trucks on the road. Despite these recent anomalies, both the road freight industry and government have made impressive progress in the fight against load mass contraventions over the last decade. Paul Collings weighs up their successes against trucking’s perennial ‘push for payload efficiency’. 

South Africa’s road network is a national asset in a sorry state of repair. In a recent article published in The Star newspaper, it was reported that “sixty percent of South Africa’s 754 600km of roads have been classified as ‘poor’ or worse.” 

The international benchmark for a country’s roads being ‘poor’ or ‘very poor’ is 10 percent, which, coupled with the fact that potholes and crumbling road pavements are costing motorists (including truckers) an estimated R20-billion a year in fuel use, vehicle repair costs and tyre wear, merely emphasises the enormity of the problem. 

Once again, it’s the trucking industry that bears the brunt of this ‘problem’, with truck overloading being tagged by both law enforcement and the media as the prime culprit responsible for road damage. While overloaded vehicles do have an incrementally higher impact on road surfaces than legally loaded ones, there are other factors that have contributed to the situation. 

Serious backlog

The Automobile Association of South Africa (AA) states in its “20 Year Review of the State of National and Provincial Roads in South Africa” (Compiled by Dr John Sampson and published in 2008): 

“Overloading of heavy vehicles causes roads to deteriorate at very high rates. A truck that is 10 percent overloaded causes more than double the damage of a legally loaded vehicle. A twenty percent overloaded vehicle causes four times the damage. Damage to the road network due to overloading amounts to billions of rand per annum. Various other factors can influence the rate at which the condition of the country’s roads will deteriorate. These include: high traffic volumes which increase road wear; higher than normal rainfall accelerates the deterioration of roads; flooding, like that experienced during February 2000, causes additional damage or even the complete loss of roads, and the destruction of bridges and culverts.” 

The AA Review adds that: “South Africa’s road network has continued to deteriorate in the last 10 years, albeit at a slower rate than between 1988 and 1998. The replacement value of South Africa’s national and provincial road network is estimated at R1 trillion (R1 000 billion). This includes all bridges, structures, cuts and fills. The actual road pavement and layerworks value, where most of the maintenance is concentrated, is approximately half that value at R520 billion. 

“The maintenance backlog is estimated at R100 billion, of which R95 billion is for Provincial roads and the remaining R5 billion for National roads (including approximately 9 000 km of previously provincial roads that have been taken over by SANRAL in the last eight years). In order to maintain paved roads in good condition, around R120 000 per kilometre per annum needs to be spent. The national and provincial budget requirement for maintenance is estimated at R32 billion per annum (1.5 percent of GDP). Current expenditure is about one quarter of that figure.”

The battle against overloaded trucks is primarily geared towards combating the destruction of SA’s road network.

Troubled modes

The failure of rail as a viable freight mover has placed a huge burden on our road network. Trucks remain the primary form of freight-haul across land and as our economy grows, so too do fleet numbers, exacerbating an already critical situation. 

According to the CSIR’s Fifth Annual State of Logistics Survey for South Africa 2008: “Close to 1.6 billion ton of freight was observed on the four different typologies in South Africa in 2007. Almost 1.4 billion ton was observed on road at an average transport distance of 178 km, delivering 245 billion ton-km. Rail only contributed 205 million ton at an average transport distance of 629 km, delivering 129 billion ton-km. The market share split for road and rail by tons transported thus stands at 87/13. This points to an unsustainable situation; a viable domestic intermodal solution that will reduce risk and lower costs is still necessary.” 

The irony in the ‘overloaded trucks’ saga is that the offenders are actually shooting themselves in the foot. Not only do they risk immediate punishment by law enforcement but they effectively destroy the very thing that keeps them in business - decent roads! In addition, damaged road surfaces are unsafe, cause congestion, add to fleet operating expenses and hamper turnaround times. 

While the responsibility for road maintenance lies with government, fleet owners must assist in preserving our road network by loading legally. 

Bridge work

While the occurrence of overloading has been impressively curtailed by law enforcement over the past years, it remains a problem and government has, via its National Overload Control Strategy, ploughed millions of rands into the establishment of new weighbridges and weigh-in-motion (WIMs) sites around the country. 

Every year, FleetWatch refers to the Annual KwaZulu-Natal (KZN) Department of Transport Overload Report, compiled by John Schnell of the KZN Road Traffic Inspectorate and the CSIR. While the report deals solely with data collected from KZN province, it remains the definitive account of overloading trends within the country. 

During 2008, 200 030 vehicles were weighed at the KwaZulu- Natal Department of Transport’s weighbridges of which 36 177 (18.1 percent) were overloaded and 9 901 (5 percent) charged. Of the 200 030 vehicles weighed, 138 226 (69 percent) were weighed on the N3 corridor,” the Report states. 

“Of these, 23 781 (17 percent) were overloaded and 5 652 (4 percent) charged. In comparison, in the remainder of the province (primarily the N2 north corridor) 18.9 percent of the vehicles weighed were overloaded and 4.4 percent were charged. The number of vehicles weighed during 2008 represents an increase of 4.4 percent compared with the 191 616 vehicles weighed during 2007. 

“The number of vehicles overloaded increased by 1.9 percent from 35 487 to 36 177 and the number of vehicles charged increased by 4.7 percent from 9 461 during 2007 to 9 901 during 2008. Prior to 1990, less than 10 percent of the overloaded vehicles were overloaded within the tolerance. This percentage increased to 78 percent in 2005, which is an indication of the reduction in the degree of overloading. In 2006, the percentage of overloaded vehicles overloaded within the tolerance reduced to 73 percent and remained at 73 percent in 2007 and 2008.” 

The eight most common vehicle classes weighed during 2008 were the 7-axle interlink with three tandem axle units (class 1222), the 6-axle articulated truck with a rear tridem axle unit (class 123), the 2-axle rigid truck (class 11), the 5-axle articulated truck with a rear tandem axle unit (class 122), the 4-axle articulated truck, with a single drive axle and tandem axle unit on the semi-trailer (class 112) and the 5-axle articulated truck, with a single drive axle and tridem axle unit on the semi-trailer (class 113), the Report continues. 

“The last two vehicles classes (with single drive axles) are frequently found to be overloaded due to the requirement that the total combination mass may not be more than five times the mass on the drive axle. These eight vehicle classes represent 95 percent of all heavy vehicles weighed and 96 percent of all overloaded vehicles.” 

Trucks carrying livestock and Dangerous Goods (chemicals & fuel) appear in the top ten commodities in terms of overloaded vehicles  Paul Nordengen, CSIR

Cargo culprits

With the most serious recorded gross overload in the Report weighing just over 24 tons, “the top three commodities, in terms of the number of vehicles weighed in 2008, were classified as ‘goods’; ‘containers’; and ‘unknown cargo’. This highlights the need to improve the correct recording of the cargo during the weighing procedure and this should be communicated to the staff at the weighbridges,” the Report states. 

According to the CSIR’s Paul Nordengen, “trucks carrying livestock and Dangerous Goods (chemicals and fuel) appear in the top ten commodities in terms of overloaded vehicles. This is cause for concern as these dangerous goods are generally perceived to be well regulated in terms of the SANS codes of practice.” 

According to Schnell, “weighing activities by the KwaZulu-Natal Department of Transport have been increasing since 2005 and the number of vehicles weighed in 2008 is the highest since 1988. The heavy vehicle overload situation in KwaZulu-Natal has however stabilised in terms of the extent and degree of overloading, with the 2008 levels more or less the same as those of 2007. Indications are therefore that an increased effort would be required to reduce overloading further.” 

Trucks being parked off at weighbridges for load mass contraventions can also risk losing payload while the freight is transferred to another truck.

Peaks and troughs 

Toll road concessionaires N3TC and TRAC both report that diesel price increases in 2008 and this year’s credit crisis have seen marked spikes in overloading trends. While overloading is under control on the main corridors in South Africa, Nordengen states that provincial roads are not policed adequately. 

“Sugar, timber and coal trucks use secondary roads and it is estimated that 80 percent of all truck kilometres travelled are done so unchecked. Traffic officials only weigh around five percent of the national truck parc and it is clear that overload control capacity needs to be escalated in all provinces, particularly on secondary roads,” he says. 

With the financial and skills constraints facing the National Department of Transport, the best route to effective overload control might well lie in the ‘self-regulation’ approach like the Road Transport Management System (RTMS) which is making a significant difference to load compliance in the timber and coal industries. 

“The coal industry has seen a 50 percent reduction in overloading since the introduction of RTMS. Initiatives like this, coupled with new legislation governing consignor/ consignee obligations will take the fight against overloading to the next level,” concludes Nordengen.