[en] The investigation of weather effects on traffic intensity is important from a road safety point of
view, because traffic intensity is noted as the first and primary determinant of traffic safety. Next
to traffic safety, weather conditions affect other predominant traffic variables, namely traffic
demand and traffic flow. Therefore the main objective of this study is the identification and
comparison of weather effects on traffic intensity at different site locations. To assess the impact
of weather conditions on traffic intensity, the upstream and downstream traffic of four traffic
count locations are considered. The traffic intensity data originate from minute data coming from
single inductive loop detectors, collected by the Flemish Traffic Control Center. Data concerning
weather events were recorded by the Royal Meteorological Institute of Belgium. The main
modeling philosophy envisaged in this study to identify and quantify weather effects is the linear
regression approach. Most appealing result of this study for policy makers, is the heterogeneity
of the weather effects between different traffic count locations, and the homogeneity of the
weather effects on upstream and downstream traffic at a certain location. The results also
indicated that snowfall, rainfall and wind speed have a clear diminishing effect on traffic
intensity, while maximum temperature significantly increases traffic intensity. Further
generalizations of the findings are possible by studying weather effects on local roads and by
shifting the scope towards travel behavior. Simultaneously modeling of weather conditions,
traffic intensity rates, collision risk and activity travel behavior is certainly a key challenge for
further research.
Research Center/Unit :
Lepur : Centre de Recherche sur la Ville, le Territoire et le Milieu rural - ULiège LEMA - Local Environment Management and Analysis
Disciplines :
Civil engineering Special economic topics (health, labor, transportation...)
