Research On Accessibility And Its Computation Based On Space-Time Prism

Accessibility is an important indicator of whether a regional plan is reasonable or not,and can reflect the ease with which a moving individual can reach a certain location within a given time frame.In recent years,the calculation of accessibility has become a hot issue in time geography research.Among them,the calculation of accessibility based on time-space prisms has also achieved many advances,and several measures of common accessibility calculation have been put forward.However,they do not consider:(1)the ability of individuals to adjust their activities to deal with restricted travel options;(2)the uncertainty of travel time perception;(3)the temporal variability of travel time;(4)the impact of the traveler's information on accessibility.In this article,we mainly consider the following contents:1.We introduce the basics of accessibility and time geography,and expound the theoretical framework of accessibility research as well as the concepts and applications of time-space prisms.2.The application of space-time prisms in accessibility measurements is developed.Concretely,the given approach based on geographic information system is used to locate the facilities included in the space-time prism,and use the data from Portland,Oregon,USA to show how to use it to measure the accessibility of health care facilities and the accessibility from an operational perspective.3.The numerical simulation is used to study and explain the shortcomings of the existing accessibility calculation method,and to propose effective accessibility measure.The results show that the proposed accessibility measure is a useful indicator of the social inclusion of individuals who can be used to conduct the preferred activity.In addition,it is found that the accessibility is limited by the existence of time delay penalties,and can determine the impact of travel time information provided.