The value of travel time savings in freight transport: a meta-analysis

The value of freight travel time savings (VFTTS) is a monetary value that is considered an important input into cost–benefit analysis and traffic forecasting. The VFTTS is defined as the marginal rate of substitution between travel time and cost and may therefore differ across firms, time and countries. The paper aims to explain variations in the VFTTS by using the meta-analysis method. The analysis covers 106 monetary valuations extracted from 56 studies conducted from 1988 to 2018 in countries across the globe. The meta-analysis method determines the factors that have an impact on these VFTTS variations. The paper briefly introduces the VFTTS concept and describes the adopted meta-analysis methodology, wherein different meta-models are used in VFTTS estimations. The results highlight the necessity of including multiple explanatory variables to ensure adequate explanation of the VFTTS variations. The findings also show that GDP per capita, transport mode and type of survey respondent are statistically significant variables. The paper sheds some light on the variations, thereby advancing the understanding of each factor’s effects on the VFTTS. Furthermore, meta-model outcomes are used to generate new values of travel time savings for different transport modes in freight transport, for several countries. These implied VFTTS can be used as benchmarks to assess existing evidence or provide new evidence to countries where no such values exist.