it does not calculate cycling access to bus stations as it is assumed that bus services are accessed by walking only the main purpose of comparing cytal and ptal is to highlight areas where ptal is low by itself but can potentially be raised by including cycling as an access mode this measure however does not take into account the availability of cycling infrastructure such as parking at origin or destination or the suitability of the cycle network for a given trip thus this indicator serves tfl for strategic cycling analysis and helps identify areas for potential future cycling infrastructure investment in the greater london area most importantly such analysis requires additional quality data on availability of cycling infrastructure including parking and dedicated cycling lanes and on perceived safety and overall convenience of cycling in various areas across london however they do not capture the actual accessibility needs of various groups of people