AN IMPROVED METHODOLOGY TO DETERMINE THE WIGGLE FACTOR: AN APPLICATION FOR SPANISH ROAD TRANSPORT

摘要

The Wiggle Factor (WF) is a correction factor defined as the ratio between the real distance travelled by road and the straight line between the two points. It is commonly used to estimate route distances for land transport. Though WF is an approximation, certain degree of accuracy is required, because it is frequently used to calculate fuel costs (which represent approximately half of the total truck costs). Performing a statistical analysis with more than 10.000 routes, this article shows that the most common Wiggle Factor (1.2) is not a good approximation for Spanish roads, thus two different WF are presented: the first WF (1.36) characterizes mainly road infrastructure in rural areas while the second WF (1.29) characterizes high-capacity roads (typically motorways). In addition, we present a methodology to easily calculate a WF that can be applied to other countries or specific zones.