FTIR spectroscopy was used to compare a direct and continued methodological approach of bitumen oxidation process (adapted IR cell), a road ageing, along with two ageing conventional tests: the Rolling Thin Film Oven Test (RTFOT) and the Pressure Ageing Vessel (PAV). This work gave clear indication that oxidation inside a cell can partly simulate the chemical evolution of road bitumens actually in service. Indeed, regarding the formation of carbonyl functions, an hour of cell oxidation is equivalent to two years of ageing on site. Furthermore the PAV ageing protocol could be simulated by 25 min of cell oxidation. (C) 2001 Elsevier Science Ltd. All rights reserved.