Abstract
The surface public bus has a great advantage in mitigating traffic congestion in Beijing city in a short-term period and accessibility analysis of public bus network is one of the most important topics for urban sustainable development. On the basis of actuality analysis of such indexes as line length, network density, repetition coefficient of public bus network in Beijing, the paper improved the Critical Cluster Model (CCM) which is one of the spatial optimization models applying to the assessment of evacuation risk and introduced a new concept the maximum bus line capacity demand for the bus stop. It evaluated the accessibility of Beijing public bus network with the reformative CCM and GIS technology. The results revealed the accessibility characteristics and the existing problems, which will help to the further improvement program.
