This paper studies inter- and intramodal competition in the London-Paris passenger market during the period 2003-2009. We identify the degree to and conditions under which High-Speed Rail is a viable substitute for airline travel. Using pooled cross-sectional data we estimate multinomial and mixed logit models to examine actual travel behaviour. Our model allows us to analyse the reaction of passenger behaviour on the withdrawal of aviation alternatives and the completion of the High-Speed Rail link between the two cities in November 2007. The results show that travel time and frequency are the main determinants of travel behaviour. The valuation of total travel times changes over the years following the opening of the High-Speed Rail link. Furthermore, we show that the direct elasticity of market share with respect to frequency for a number of aviation alternatives is above 1, indicating that these alternatives are not able to maximise profits. These alternatives subsequently left the market in our sample period. For the remaining aviation alternatives, except for easyJet, we find elasticities of market share with respect to frequency close to 1. Therefore, we conjecture that competition in this market will decline in the long run. © 2011 Elsevier Inc..