Generalization is a complex task which requires a good understanding o
f the geometrical and semantic aspects of map features as well as the
potential use of the map. Reasoning about spatial relationship, compar
ing alternative solutions, and contextual thinking are all important a
ctivities required for generalization decision-making. Such activities
are not easy to simulate in a computer without sufficient information
and the support of good data structures and adequate reasoning mechan
isms. This paper introduces a dynamic decision tree structure in an at
tempt to partly circumvent the problem of urban road network generaliz
ation through the use of object classification and aggregation hierarc
hies, topological data structure, decision rules, and AI technology. A
part from the construction process, it also discusses the reasoning pr
ocess for decision-making, and provides two test results with some dis
cussion on the benefits and short-comings of the proposed approach.