Developers lean on PTAL as the indicator in such assessments for London projects, as it helps them evaluate how new development would affect accessibility to public transport in a selected area and determine the acceptability of the impact. While it provides a useful indicator of local accessibility and allows easy comparison of areas across the city, one criticism is that it assumes access to a public transport network includes access to reasonably well-integrated rail and bus services and, by implication, to a range of final destinations. But PTAL does not in fact measure access to final destinations. That said, the Access to Opportunities and Services (ATOS) indicator - a complementary TfL measure that does reflect access to destinations and is described below - shows that in the case of London, a city with a comprehensive and relatively dense public transport network, PTAL is a good proxy for access to services and opportunities. In areas of lower density, however, the PTAL method may not be applicable as they usually have a sparser public transport network with poor connections and interchange facilities. Nor does it account for availability of cycling lanes or quality of walking environment.