This project investigates the policy challenges posed by the operation of agricultural vehicles on public roads in Australia and New Zealand. This is the final report for the project, which was conducted in three stages. Stage 1 sought to understand the driving forces behind future changes to agricultural equipment, and to catalogue the technical specifications of agricultural equipment that is expected to become available in Australia in the next five to ten years. Stage 2 sought to quantify the potential safety and infrastructure impacts of that equipment. Stage 3 collated the findings of the first two stages and produced the project’s final report. Stage 1 comprised an industry survey of two stakeholder groups; suppliers and manufacturers of agricultural equipment, and agricultural industry associations. The responses provided insights into trends in the agricultural industry, and helped to identify that the most likely scenario for the future involves gradual, incremental increases in the average physical size and mass of most equipment, driven primarily by economic forces and the need for greater productivity and efficiency. Equipment used by the broad-acre grain sector is expected to grow in size and mass above the current regulated limits, and some equipment currently available exceeds limits in some jurisdictions. This includes comb trailers, tillers and drill seeders, and field and chaser bins. Stage 2 reviewed and summarised the jurisdictions’ policies on agricultural vehicle mass and dimensions, identified the discrepancies between the policies and the current/future agricultural fleet, and conducted technical assessments to investigate the impacts. Current regulatory approaches aim to manage safety and infrastructure risks by limiting mass and dimensions, requiring the fitment of safety devices, the use of pilots/escorts, setting maximum speed limits, towed-to-towing vehicle mass ratios, and minimum brake performance levels, and other operating conditions such as curfews and licensing. The current policy instruments vary widely in their scope and level of detail. While there is some commonality in the ranges of masses and dimensions, upper mass and dimension limits vary between jurisdictions. Additionally, some jurisdictions are completely silent on critical safety matters such as braking requirements, towed mass ratios, modifications to vehicles and equipment, minimum levels of safety equipment, and operator licensing. Hence, only a portion of the known safety and infrastructure risks are being effectively addressed at present, although this varies across jurisdictions. The assessment of the discrepancies between current policies and the current/future agricultural fleet identified increased tare mass, laden operation, and increased height, length, width and rear overhang. These may cause increased levels of pavement wear, greater bridge impacts, reduced braking capability, reduced rollover stability, reduced acceleration capability, increased risk of striking overhead structures, and to impact road safety and infrastructure due to increased road space requirements when turning and manoeuvring. The impacts of discrepancies were investigated via investigations into potential pavement and bridge impacts, brake performance, rollover threshold, and road space requirements. Data on agricultural vehicle crashes was also was reviewed to understand if any correlation could be drawn between the causes of crashes and aspects of agricultural vehicles that are considered to pose safety risks. It was found that: * some agricultural combinations have greater pavement and bridge impacts than the chosen reference vehicle (a 40-tonne four-axle mobile crane complying with the requirements of the future National Class 1 SPV Notice) * road space requirements of current and future vehicles are generally equal to or lesser than vehicles allowed under current policies * the rollover threshold of the agricultural fleet was generally higher than conventional heavy vehicles. An assessment of braking performance could not be conducted due to a lack of performance data. Previous research indicates that some agricultural combinations with towed mass ratios exceeding 1:1.2 may not be able to achieve a safe level of braking performance, however that investigation was limited in its scope. Limitations in the crash data reduced the usefulness of the conclusions that could be drawn from the analysis. Notwithstanding this, it is likely that the increased length and width of agricultural vehicles may have been a factor in the crashes that occurred during overtaking manoeuvres. Agricultural vehicle braking performance and the speed differential between agricultural vehicles and other road users may have been factors in the rear-end and overtaking crashes. It is also likely that increases in the length, width, and mass of agricultural equipment and combinations would have a detrimental effect on road safety, particularly where other road users are involved. It is recommended that the current limitations and variations in existing policies should be addressed as a priority, not only to ensure that the risks are managed, but also to provide greater clarity and certainty to the agricultural industry. Limits and requirements should be harmonised across jurisdictions to the greatest extent possible, in a similar manner that has been achieved in the conventional heavy vehicle industry since the creation of the National Heavy Vehicle Regulator. While the provision of detailed policy options is outside the scope of the current project, the research conducted allows some recommendations on specific areas to be made: * The length limits for single units in broad-acre areas could be increased to allow any trailer up to 25 metres long to be towed, which would cater for the longest augers, comb trailers, field bins, and most end-tow tiller drill/seeders that may become available in the foreseeable future. * A maximum overall length limits of 35 metres could be reasonably retained as the maximum for combinations in broad acre areas. The swept path of such combinations is likely to be similar to conventional Type 1 and 2 road trains. * Such combinations could be permitted to tow another small trailer, such as an air compressor or a passenger car, as the impacts assessment showed that the increase in length would not negatively affect the overall swept path result. * Rear overhang limits for harvesters, comb trailers and field bins operating in broad acre areas. could reasonably be increased to six metres, and 10 metres for augers. Axle load and gross mass limits could be aligned with the national notice for mobile cranes, although the suitability of those limits for axles fitted with agricultural-style wide tyres would need to be determined. Laden operation could be permitted, provided that suitable axle loads were determined, and a maximum towed-mass ratio was enforced. Prior research indicated a maximum towed mass ratio of 1:1.2 for an acceptable level of braking performance, although that study was limited in its scope. The Project Reference Group indicated a preference for permitting passenger vehicles to tow agricultural combinations, provided that the vehicle manufacturer’s braked and un-braked towing ratings are not exceeded. It should be made clear to the industry that the jurisdictions cannot (and should not be expected to) allow manufacturer’s safe limits to be exceeded through their policies. There is also a need for agricultural equipment manufacturers and dealers to clearly outline to purchasers their responsibilities and the legal requirements that need to be observed in the transport of agricultural equipment. The NHVR and the jurisdictions should take steps to encourage this, including the provision of nationally-consistent agricultural vehicle policies. Within this task, further additional research is required to determine appropriate policy responses on a range of areas, including minimum levels of safety equipment, modifications to equipment, licencing, methods for determining access, and night travel. (Author/publisher)
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