Unintended environmental impacts of metropolitan freight logistics policies

In recent years, the reduction of the negative externalities resulting from freight logistics transportation has increasingly been a metropolitan policy goal. Such policies have often been justified by studies which conclude beneficial environmental impacts. However, these studies have often been incomplete, leaving significant questions about the direction that policies should take in the future. Two policies are found to be pervasive in implementations around the world. These are aimed at reducing the number of road freight trips through an increase in loads and those to reduce the number of peak-hour trips.;Heavy freight vehicles cause most of the damage incurred by pavements. The supply chain associated with pavement maintenance and construction releases significant pollutant emissions, raising the question of whether increased vehicle weights may cause unintended environmental consequences. This dissertation presents case examples with estimated emissions resulting from shifts in load consolidation and increased maximum weight. These examples indicate that increased load factors in local and long-distance freight movement can cause significant increases in emissions of certain pollutants. Emissions associated with pavement construction are also found to increase as a result of pavement design specifications that account for heavier vehicles. This topic integrates concepts of life-cycle assessment and infrastructure management.;The atmospheric boundary layer is generally more stable during the night than the day. Consequently, shifting logistics operations to the night would increase the 24-hour average concentrations of diesel exhaust pollutants in many locations. This dissertation presents case examples of this phenomenon, which provide concentration estimates after temporal redistributions of daily logistics operations. In addition, congestion is considered through examples which show the effects on traffic speeds of shifting vehicle trips and the subsequent effect on emissions factors and pollutant concentrations. As a result a new tool is presented, which can be used to assess whether or not an off-peak policy would be damaging in different contexts. This tool is used to depict various regimes in which unintended environmental damage can occur for multiple environmental impacts. This topic integrates concepts from the fields of air quality engineering, atmospheric science and traffic flow theory.