- Ermagun, Alireza, and Levinson, D. (2016) Public Transit, Active Travel, and the Journey to School: A Cross-nested Logit Analysis. Transportmetrica A: Transport Science. [doi] [49 free copies]
Apart from the active travel modes, public transit is an opportunity to accomplish a portion of the recommended daily physical activity. Much of the previous research has been limited to descriptive analysis for quantifying the active component of public transit by the complexity associated with advanced econometrics models. This paper overcomes this challenge by applying a two-level cross-nested logit model. We used the school trip information of 3,441 middle and high school students in Tehran for this analysis. We showed a 1% increase in home-to-school distance reduces physical activity by 0.91%. Building on the traditional models, which consider public transit a solely non-active mode, this reduction equals 2.21%. Therefore, ignoring the “quasi-active” role of public transit overestimates the physical activity reduction of students by 142%. We also found a 1% decrease in access to transit stations diminishes physical activity by 0.04%. This diminish is 0.02% when we used the traditional nested logit model. This is the direct consequence of the model misspecification stemming from ignoring the active component of public transit trips.