Introducing Human Factors in Pedestrian Crossing Behavior Models

The objective of this research is the development of pedestrian crossing choice models on the basis of road, traffic and human factors. For that purpose, a field survey was carried out, in which a panel of 75 pedestrians were asked to take 8 short walking trips (each one corresponding to a different walking and crossing scenario) in the Athens city centre in Greece, allowing to record their crossing behavior in different road and traffic conditions. The same individuals were asked to fill in a questionnaire on their travel motivations, their mobility characteristics, their risk perceptions and preferences with respect to walking and road crossing, their opinion on drivers etc. The walking and crossing scenarios’ data were used to develop mixed sequential logit models of pedestrian behavior on the basis of road and traffic characteristics. The modeling results showed that pedestrian crossing choices are significantly affected by road type, traffic flow and traffic control. The questionnaire data were used to estimate human factors (components) of pedestrian crossing behavior by means of principal component analysis. The results showed that three components of pedestrian crossing behavior emerge, namely a “risk-taking and optimization” component reflecting the tendency to cross at mid-block in order to save time etc., a “conservative” component, concerning individuals with increased perceived risk of mid-block crossing, who also appear to be frequent public transport users, and a “pedestrian for pleasure” component, bringing together frequent pedestrians, walking for health or pleasure etc. The introduction of these components as explanatory variables into the choice models resulted in improvement of the modeling results, indicating that human factors have additional explanatory power over road and traffic factors of pedestrian behavior. Therefore, the development of integrated choice and latent variables models appears to be an appropriate field for further research. Key-words : pedestrian behavior; human factors; mixed logit models. TRB 2015 Annual Meeting Paper revised from original submittal. Papadimitriou E., Lassarre S., Yannis G. 3 BACKGROUND AND OBJECTIVES The analysis of pedestrians crossing behavior in urban areas may assist in the understanding of the way pedestrians interact with the road and traffic environment, as well as with other pedestrians, and the way they balance the need for comfort and safety with the cost of delays, within the framework of existing traffic rules (1). Eventually, it may assist in the better adjustment of urban road networks to pedestrians' needs and the more accurate estimation of pedestrians road accident risk exposure in urban areas (2) and thus to the improvement of pedestrians safety. Although signalized junctions provide pedestrians a protected cross ing phase, most pedestrians tend to prefer using the available traffic gaps for crossing (3). Moreover, midblock crossing and diagonal crossing are common practice among pedestrians aiming to save travel time or distance (4). Because of their flexibility and adaptability, pedestrians generally experience smaller delays compared to other road users, but increased road accident risk exposure (5). Existing research on pedestrians crossing behavior in urban areas is extensive and in several cases it concerns gap acceptance models, in which each pedestrian is associated with a critical gap for road crossing (6, 7, 8). In several other researches, a level of service approach is implemented for road crossing, in which the difficulty to cross is used as a measure of effectiveness for pedestrian level of service (9, 10). Moreover, pedestrians' crossing choices among a set of discrete alternatives are often modeled on the basis of utility theory (4, 11, 12). A distinct part of existing research on pedestrian crossing behavior is devoted to analyses of psychological, attitudinal, perceptual and motivational factors (13, 14, 15). However, human factors are seldom incorporated in pedestrian behavior and safety models, so that the explanatory power of these factors can be tested. It is common to analyze the observed behavior of pedestrians in relation to road and traffic characteristics, and the demographic characteristics of pedestrians, or the self-reported behavior, attitudes and perceptions on the basis of questionnaire surveys, but the entire set of potential determinants has not been jointly explored in the existing studies. The objective of this paper is the analysis of pedestrians' crossing behavior along entire trips in urban road networks, with particular emphasis on the introduction of human factors (pedestrians’ attitudes, perceptions etc.) in the potential determinants. More specifically, this research aims to develop choice models for estimating the probability to cross at each location along a pedestrian trip in relation to roadway design, traffic flow and traffic control, as well as human factors. This paper starts with the description of the data collection scheme used for the purposes of this research, namely a combination of field observations and questionnaire survey. Subsequently, the analysis techniques are presented, which include mixed sequential logit models for pedestrian crossing behavior (applied on the field observations data) and categorical principal components analysis (applied on the questionnaire data). The results section follows, including the sequential choice models of pedestrian crossing behavior, the components of pedestrian human factors, and the introduction of these components into the choice models. The paper ends with a discussion of the findings, also in light of the next steps of the research. TRB 2015 Annual Meeting Paper revised from original submittal. Papadimitriou E., Lassarre S., Yannis G. 4