Behavioural aspects of transportation mode choice in the ``Energie'' S.P.P.S. survey Eric Cornelis and Philippe Toint Report 93/05 This paper analyzes the impact of behavioural variables on transportation mode choice in Belgium. The analysis is mainly based on the ``Energie'' survey from the belgian Prime Minister's Office, but also compares the obtained results with the conclusions of two independently conducted surveys in the cities of Brussels and Charleroi. The effect of length and duration of the trip, user's age and motorization level is considered.