In recent years, the reduction of freight truck trips has been a common policy goal. To this end, policies aimed at influencing load consolidationhave been suggested and implemented, resulting in higher gross vehicle weights. The purpose of such policies has generally been to mitigate congestion and environmental impacts. However, in accordance with the pavement fourth power law, trucks cause most of the damage incurred by highways pavements. The supply chain associated with pavement maintenance and construction is known to release significant pollutant emissions, raising the question of whether increased vehicle weights may cause unintended environmental consequences. This paper combines methods of environmental life cycleassessment with infrastructure management, to present hypothetical scenarios with estimated emissions resulting from load consolidation and changesin load factors. These scenarios reveal several points having to do withthe tradeoff between tailpipe versus pavement supply-chain emissions. Insome cases, unintended emissions from the pavement supply-chain are foundto be significant, indicating that the commonly assumed environmental benefits of increased truck payload and in turn reduced trips may not always hold.
Abstract