Figure 3 illustrates the relationship of the catchment area for the water transportation system at
Nonthaburi pier to the main haul distance. It shows that the maximum number of commuters is observed
at the access distance of 5 km for all classes for main haul distance. For short main haul distance, the
number of commuters accessing more than 5 km reduces proportionally as access distance increases. For
each of the other two classes, the number of commuters accessing more than 5 km reduces drastically as
the access distance increases. This implies that as the main haul distance increases the extent of the
catchment area drastically reduces. Table VII supports this observation. It can also be observed that, as
the main haul distance increases, the percentage of commuters accessing a distance of less than 5 km
drastically reduces. From Table VII, it can be seen that the percentage of commuters accessing less than
5 km for a short main haul distance is 43.0%. For medium and long main haul distances, the percentages
of commuters accessing less than 5 km are 31.0 and 32.0, respectively