Service quality in relation to frequency, availability, and accessibility is an important issue for the various stakeholders involved in high-speed rail (HSR) projects. The concept of accessibility provides the means to build relevant indicators likely to evaluate the service quality in studies of transportation supply and demand. In this paper, indicators of time available at destination (TAD) are used to measure changes in service quality in rail and air travel between Paris and Bordeaux, France. Furthermore, the paper shows for the first time that TAD is a determining factor in explaining the air-train mode choice.