Research On Modeling Method Of Individual Accessibility Based On Activity Requirement

The need to travel is a derived need. It derived from the people’s needs, such as working, studying, social intercourse, social and economic activities, as well as shopping in the urban functional partition. Therefore it should to be explored the characteristics and formation mechanism of the traffic problem from the view of the origin of traffic demand that residents activity demand perspective.In the transit system, accessibility as a measure indicators which can estimate the comfort, security, convenience, punctual and economics for individual who arrive at destination. Traditional accessibility refers to the convenience that people/cargo reach the destination or take part in activities by certain traffic tool, which decided by land use and transit system. It has a different understanding about accessibility from the perspective of land use, transit system, time restriction and individual. People is the subject in city, it is important to analyze the content of accessibility with individual. The research methods on accessibility that traditional used is evaluating the individual activities from a space-time perspective, such as cumulative opportunity algorithm, distance algorithm etc, while it is based on time geography at the present stage, we can study on accessibility from constraints of both space and time. Both of the two methods measure the accessibility in view of supply. However, the concept of accessibility shows how easily people live by travel. Only analyze practical and potentially of people travel demand based on activity demand, can we better understand and provided transport service. Thus, we put forward a new measure method of accessibility based on activity demand.Firstly, this paper focuses on the study of individual, and the needs of the residents of individual activities. And then it proposed the definition of the activity-based accessibility.Secondly, this paper analyzed the residents of the generalized travel cost is important factor of activity-based need of individual accessibility. The key factor of individual accessibility is the perception of person. Therefore, this paper considers the generalized travel cost of individual perception, mainly consisting of three parts that the cost of use, time and fatigue (comfortable and pleasant emotion cost).Thirdly, modeling the individual accessibility of activity-based on the needs, is from accessibility measure approach based on the utility of random utility theory. This paper mainly takes into account the different effects to individual choice for mode, destination and activity type. And modeling the nested Logit model with three MNL models. Model takes into account the influence factors to individual characteristics, family characteristics and travel characteristics, in addition considers an important influencing factors is the generalized travel cost of individual perception, and add to the destination selected layer model calibration. Which needed a Logsum variables connected adjacent layers.Finally, the same individual as the research object, and other transportation infrastructure and land-use facilities supply perspective, the generalized cost of travel residents viewed the degree of difficulty of space barrier indicators measure individual reachability. At the same time the demand side (based on individual accessibility needs activity measurement methods) and supply angle (using generalized travel costs measure up to the residents of) two angles measure up to the individual methods of analysis and comparison.