Commuting in multinodal urban systems: An empirical comparison of three alternative models

In commuting employees travel forth and back between their homes and their places of work
on a daily basis crossing the municipal border. The analysis uses the 1988, 1989 and 1990
Labour Force Survey (LFS; CBS 1993). This is a continuous monthly inquiry annually
reaching about 1.1% of the total population. For obtaining a reliable picture of the structural
commuting relationships the averages of the three years were taken. Combining the LFS data
over these years shows that more than 220,000 people between 15 and 65 years of age are
involved. Because the data were combined, changes within those three years could not be
examined. The lowest spatial level used in the analysis is that of 469 areas of with each has at
least 10,000 inhabitants (CBS 1993). In the rest of the article these areas are called
municipalities. Data on distances commuted were obtained by linking a distances matrix to the
LFS-files. For each respondent the distance between municipality of residence and
municipality of employment was determined.

The delineation of a daily urban system is of crucial importance for the results of the
model calculations. Basically two alternatives for this delineation exist. On the one hand the
existing political-administrative division of daily urban systems can be used, on the other
hand, the delineation can be based on the actual functional relations of the municipalities
involved in commuting. For reasons concerning the availability of data most research uses the
first alternative of existing administrative divisions. This, however, implies that relationships
with areas outside a certain division will not be part of the analysis, eventually leading to
wrong model estimates. Therefore we developed an empirical functional division of urban
regions. Starting point for the functional regional division is that the areas created are both
living and working areas. It is a major consideration that ‘the bulk of residents are employed
within the area while the bulk of jobs in the area employ residents’ (Campbell & Duffy, 1992,
p.7). We start from the assumption that, although individual differences among demand and
supply exist, aggregation of individual demand and supply is possible. This assumption is based
on a homogeneous view of the labour market. In this labour markets are spatially limited units
where supply and demand meet (Hunter & Reid 1968; Van der Laan 1991). The method used
here is based on the principle of self-containment which assumes that there will be high rates
of commuting within a defined geographical area and low rates of commuting with areas
outside (see Smart, 1974; Cervero, 1995). Crucial in this is the criteria for ‘high’ and ‘low’.

To come to the correct delineation of the four largest urban regions in the Randstad
area, we at first made a nation-wide division of commuter areas. The procedure consists of
nine steps (Van der Laan & Schalke, 1996). The results of the steps taken are shown in brief
in table 1.

Table 1 Steps taken in the development of commuter areas

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