Forestry in South Africa
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November : Survey suggests increase use of Performance-Based Standard (PBS) vehicles in the future could reduce CO2 emissions

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17 November, 2020

Survey suggests increase use of Performance-Based Standard (PBS) vehicles in the future could reduce CO2 emissions by 16.7% and save the industry over R215.9 million

Survey suggests increase use of performance-based standard vehicles in the future could reduce CO2 emissions


Over a decade ago, the Forestry Industry participated in the first Performance-Based Standards (PBS) pilot project that was initiated in South Africa by the CSIR. Fast forward 13-years and 99 PBS vehicles are operating in the industry, travelling over 15 million kilometres annually and delivering over 2.4 million tons of timber.

The use of heavy vehicles on the South African road network is controlled predominantly by prescriptive regulations. While the current standards for vehicles address a range of safety issues, there are some aspects of heavy vehicle safety performance that are not controlled by these regulations.

Performance-Based Standards (PBS) specify the performance required from the operation of a vehicle on a network rather than prescribing how the specified level of performance is to be achieved. This approach allows more flexibility for vehicle designers to utilise innovative solutions and the latest available technology to meet the required performance standards with improved safety outcomes and more effective use of the road infrastructure. PBS addresses the critical aspect of a vehicle's dynamic performance, with these vehicles needing to comply with certain prescribed static and dynamic performance standards such as Maximum Swept Path, Acceleration Capability, Static Rollover Threshold (SRT), High Speed Transient Offtracking and Rearward Amplification. The PBS approach also allows a more optimum "match" between the PBS vehicle and the road infrastructure (roads and bridges) which it uses. Heavy vehicles operated under a PBS framework are typically limited to travel on a subset of the network to ensure protection of the road infrastructure and acceptable safety levels. The introduction of PBS vehicles improves transport productivity through increased payload capacity, thereby reducing the costs associated with transporting goods. An improvement in transport productivity leads to a decrease in the amount of fuel used per ton moved, and a resulting reduction in CO2 emissions. A significant spinoff lies in the enhanced safety features inherent in the design of these vehicles.

The industry therefore sees PBS vehicles playing a key role in supporting and developing road transport systems that promote safer roads, reduce road wear and are more efficient in terms of increased payload. PBS vehicle uptake also has a role in the industry's quest to cut carbon emissions along the value chain, with the transport of timber being a major source of emissions.

The PBS concept is currently operated as a Pilot Project under the Abnormal Loads dispensation, although discussions are taking place with the National Department of Transport to incorporate the PBS concept into current legislation. To quantify the potential uptake of PBS vehicles within the Sector once the concept is accepted nationally as a transport solution, Forestry South Africa (FSA) commissioned a survey of the eight largest forestry companies. These companies represent a combined annual harvest of 11 500 000 tons, 74% of South Africa's approximate total annual harvest (15 500 000 tons).

Key findings

Participants projected that approximately 9 763 000 tons (85%) of timber will be moved annually by road, although it is worth noting that they commented they would prefer to transport higher volumes by rail, but predictions are based on current realities.

Of this 9.763 million tons, 7.684 million tons (79%) is predicted to be moved by PBS trucks, almost four times the amount expected to be transported by conventional trucks (2.079 million). While this data cannot be extrapolated out for the industry as a whole, in part as a result of route restrictions which would ensure not all PBS permits applications would be successful and also due to some companies not wishing to follow the PBS route. The data from these eight companies can be assumed to represent PBS vehicle uptake by the industry as a whole and suggests that 58% of South Africa's total timber moved by road will be done using PBS vehicles by 2030.

What does this mean for the Sector and South Africa in general?

Using the individual lead distances - the one-way distance between the source of the timber and the destination - reported by the participants (ranging from 30km-275km), it is estimated the move from conventional vehicles to PBS vehicles will accrue the following savings:

  • 53 264 trips per year (19.8% saving) - Of the 7 684 000 tons predicted by the respondents to be moved with PBS vehicles, it is predicted that 85% will be moved with the Rigid and 5-axle drawbar configuration, with a maximum combination mass of 67.5 tonnes (payload approximately 47 tonnes), and 15% with configurations exceeding this. For the sake of calculations, the larger configuration is assumed to be a Rigid truck with a twin steer axle and 5-axle drawbar configuration with a maximum combination mass of 75 tonnes (payload approximately 51 tonnes). This payload improvement from 38 tons to the higher payloads of 47 and 51 tons would result in a 19.8% saving.
  • 13.22 million kilometres annual reduction - because of the reduced number of trips.
  • 5.73 million litres saving on fuel (16.7% saving) - because of the reduced number of kilometres driven.
  • R215.9 million in annual savings - This was done using a costing model to compare conventional vs PBS. The costing was done over a 5-year period, and same brand truck (Mercedes Benz) and Trailer (Afrit) were used, but naturally different models. The costing model takes into account 140 items, including: Purchase price of vehicles (PBS is higher); Fuel consumption (PBS is higher); Driver wages (PBS is higher); Payload (PBS is higher); Traveling time (PBS is slower); Loading and offloading time (PBS is longer); Tyres (PBS is higher) etc. The costs were calculated per lead distance provided by the participants. This was done to ensure accurate costing. The rate on a short distance might look better in Rand/ton, but when you work it back to R/km, the short distances are more expensive per km than the long distances. This is because on a short lead, the traveling time makes up a smaller percentage of the total time it takes to do one cycle, than a longer lead would.
  • 15 130 tonnes reduction in CO2 emissions annually, a 16.7% saving.


While the Industry will be the chief beneficiary of the financial savings made by moving over to PBS vehicles, all road users will benefit from fewer forestry trucks on the road. Especially, as the use of PBS vehicles has been shown to have a 42% reduction on crash rates when compared to conventional vehicles.

The move also helps towards South Africa's pledge to cut CO2 emissions.

By Francois Oberholzer
Forestry South Africa - Operations Manager