Results from an analysis of traffic accidents from a study of the poli
ce records of four police stations in the Bangkok metropolis are prese
nted. The main emphasis in this study was put on the development of a
measure for traffic accident density. The traffic flow was estimated a
t the various study locations by trained experts. By relating the freq
uency of traffic accidents found in the police records to the independ
ently estimated traffic flow, a measure for traffic accident occurrenc
e, the traffic accident density, was constructed and estimated for the
47 areas in four study locations. The spatial risk structure was esti
mated and three risk groups were identified. Each area was classified
into its associated risk group, and traffic accident maps for the four
study locations in the Bangkok metropolis are provided here. The impl
ication for prevention strategies is discussed.