Significant research into the latest tire technology has yielded promising outcomes for the country's vehicle fleets and roadways.
Significant research into the latest tire technology has yielded promising outcomes for the country’s vehicle fleets and roadways.
The Truck Industry Council (TIC) and the National Heavy Vehicle Regulator (NHVR) have unveiled the results of their recent research endeavor exploring the effects of the next phase in tire advancement – wide tires, commonly known as ‘Super Singles’.
While wide single and ultrawide single tires have been present in the global market for many years, a comprehensive investigation into their impact on Australian road infrastructure, particularly sprayed seal unbound granular pavements, was absent until now.
The study’s findings indicate that a wider adoption of wide tires across various vehicles would not lead to heightened road damage or increased wear.
This knowledge has always been a barrier to the adoption of next generation wider tyres in Australia.
To address the knowledge gap, a large-scale testing program using the National Transport Research Organisation’s (NTRO) Accelerated Loading Facility was conducted.
Nine identically designed pavements were constructed, with each loaded repeatedly to determine the relative rate of pavement wear for each tyre.
The results showed the pavement deformation rates for both the dual tyres and single tyres were within a similar range, and the 255/70R22.5 dual tyres caused the highest deformation rate.
The comparative pavement wear of super single tyres was not as sensitive to modest variations in inflation pressure, when compared to duals.
“Taking a real-world perspective on the comparatively small differences in pavement wear found, the pavement damage exhibited by the commonly used 11R22.5 dual tyre configuration was notably influenced by inflation pressure, with the highest damage observed when these tyres were over-inflated – a common occurrence in practice,” TIC technical officer Paul Caus says.
“In addition to the finding, day-to-day use of single tyres makes it easier for drivers to check tyre conditions, monitor inflation pressures and inspect brake components reducing the risk of overheating brakes and wheel end fires.
Caus says It can be expected that in real world conditions, the wider adoption of wide tyres would not cause a discernible increase in road pavement wear.
“TIC’s view is that there is no justification in limiting axle masses when using appropriate wide single tyres given the improved vehicle stability and efficiency they bring. They should be permitted to operate at the same mass as equivalent dual tyred axles,” he says.
NHVR’s Chief Safety and Productivity Officer David Hourigan welcomes the report’s findings.
“The findings of this report will be of great importance to equip road managers and the NHVR with the knowledge needed during consideration of vehicle load limits and the benefits provided by super single tyres,” Hourigan says.
The project was funded by the NHVR’s Heavy Vehicle Safety Initiative, supported by the federal government, and was led by TIC, the peak industry body representing truck manufacturers and importers in Australia.
TIC would like to acknowledge project partners the NTRO (formerly ARRB), and tyre suppliers Goodyear and Michelin for their expertise and efforts to deliver this important research.