3. Methods
3.1. Questionnaire design and data collection A questionnaire survey of truck fleets conducted in Nanjing from May to July in 2010 was used to collect the information used in this study. Interviews were conducted using a structured questionnaire. The questionnaire was designed considering previous studies and the research framework presented in Fig. 1. A draft questionnaire was designed and pretested before the main survey. The pretest involved 10 respondents who had knowledge concerning green logistics. These 10 respondents were asked to comment on the length of the questionnaire, the format and the wording of the scales. Reliability analysis was used to check the items in the questionnaire, which resulted in some items being revised