In conclusion, commuter exposures vary significantly among
motorcycle, car, bus and MRT. More mode-specific exposure
assessment on PM seems to be necessary because it is
impossible to extrapolate the concentrations from one mode
to another mode. In addition, information about certain
events during commutes should be collected. Finally, current
fixed-site monitoring station data cannot be readily applied to
estimate commuter exposures because they either overestimated
or under-estimated the real exposure. Future
fixed-site monitoring station data can better estimate commuter
exposures by refining either spatial or temporal
attributes of monitoring data related to commuter exposures,
such as the traffic condition surrounding commuters, the
changing distance between the fixed-site monitoring station
and commuters, and more detailed time resolution of the
fixed-site monitoring data.