The tilt mechanism reduces the lateral acceleration perceived by the passengers. Therefore, tilting trains, if provided with a suitable running gear, may run at higher cant deficiencies than non-tilting trains. However, the nominal track geometry still defines a ceiling for permissible train speed, but at a higher level. A general overview of considerations for the track is given in Chapter 2. Recent research on track/vehicle interaction, with a focus on the track geometry, is presented in Chapter 3. A simplified model for predicting comfort variables, based on the same quasi-static assumptions as in many track standards, is presented and validated in Chapter 4. Due to lack of knowledge of the motions that provoke nausea, the model only predicts roll velocity which can be compared with a Japanese limit of 5 degrees per second. Track standards from certain countries using tilting trains are presented in Chapter 5. The standards are analysed in Chapter 6, firstly, with respect to potentials for increasing permissible speeds on existing lines and, secondly, with respect to passenger comfort (using the simplified model presented in Chapter 4). Chapter 7 presents and summarises the following conclusions. Modern track components are generally capable to carry the load caused by high cant deficiencies. However, certain countries apply more restrictive rules for permissible cant deficiency at switches and crossings and at "stiff" track points, such as ballast free track on bridges, transition between ballasted and ballast free track, expansion joints, level crossings etc. The major track aspects of tilting trains are related to the horizontal alignment and cant, since the relation between low-frequency variables, such as roll velocity, lowfrequency lateral jerk etc. depends to a high degree on the horizontal alignment. Alignment design is a balancing act between conflicting objectives, such as large curve radii and long transition curves. The optimum transition curves are longer for tilting trains than for non-tilting trains. Horizontal curves without transition curves eliminate the advantage with tilting trains. The most cost-effective opportunity to arrange long transition curves is when designing a new line or a major re-configuration. Existing railways are often provided with shorter transition curves than optimal. Hence, and track renewals (when rails and sleepers are renewed) should be used to optimise the transition lengths, as a natural part of the infrastructure owner's asset management.