Abstract

This presentation will discuss the most important factors that influence the energy consumption of road freight transport. These include: vehicle engine efficiency; aerodynamic drag and rolling resistance; vehicle configuration (number of vehicle units); traffic congestion; speed; payload factors and the use of regenerative braking. In particular it highlights the importance of both logistical factors and vehicle engineering.

The presentation will conclude that improving engine efficiency, rolling resistance and aerodynamic drag can yield relatively small improvements in fuel consumption, compared with the other factors. Larger vehicles are always significantly more energy efficient than smaller ones when fully loaded and transferring freight from articulated vehicles onto smaller rigid vehicles for urban deliveries typically increases fuel consumption by approximately 35%. Running vehicles partially loaded can increases the energy per unit freight task by as much as 65%. Finally, for urban start-stop conditions, use of regenerative braking systems can reduce heavy vehicle fuel consumption by 25-35%.