For the first stage, 30 relatives of
our research group members were invited to participate in the survey
and they offered a large number of useful suggestions about
such issues as application enhancement and survey process design.
For the second stage, a selection of respondents were recruited
from relatives and friends of members of our research group, while
others were recruited from the Internet. The respondents are generally
restricted to work commuters in any district in Shanghai, in
order to facilitate generation of sufficient number of trips. More
details about the survey design and items included in the survey
questionnaire can be found in another one of our studies
(Xianyu, Juan, Xiao, & Fu, 2014).