Young driver risky behaviour and predictors of crash risk in Australia, New Zealand and Colombia: Same but different?

Urban walkability considering pedestrians’ perceptions of the built environment: a 10-year review and a case study in a medium-sized city in Latin America

Local density, which is an indicator for comfortable moving of a pedestrian, is rarely considered in traditional force based and heuristics based pedestrian flow models. However, comfortable moving is surely a demand of pedestrian in normal situations. Recently, Voronoi diagram had been successfully adopted to obtain the local density of a pedestrian in empirical studies. In this paper, Voronoi diagram is introduced into the heuristics based pedestrian flow model. It provides not only local density but also other information for determining moving velocity and direction. Those information include personal space, safe distance, neighbors, and three elementary characteristics directions. Several typical scenarios are set up to verify the proposed model. The simulation results show that the velocity-density relations and capacities of bottleneck are consistent with the empirical data, and many self-organization phenomena, i.e., arching phenomenon and lane formation, are also reproduced. The pedestrians are likely to be homogeneously distributed when they are sensitive to local density, otherwise pedestrians are non-uniformly distributed and the stop-and-go waves are likely to be reproduced. Such results indicate that the Voronoi diagram is a promising tool in modeling pedestrian dynamics.

A pedestrian flow model considering the impact of local density: Voronoi diagram based heuristics approach

This paper reports the results of a study to understand the preferences of pedestrians towards using different types of road crossing facilities. A preliminary qualitative study found that people’s perceptions about crossing facilities are shaped by aspects such as safety, convenience, crossing time, accessibility, and personal security. The main quantitative study consisted of a stated preference survey implemented in three neighbourhoods in English cities near busy roads. Participants were first asked to indicate how comfortable they felt using different types of crossing facilities. Footbridges and underpasses were systematically rated below signalised crossings. Participants were then asked to choose between walking different additional times to use certain types of crossing facility or avoid crossing the road altogether. The analysis of the choices using a mixed logit model found that on average participants are willing to walk an additional 2.4 and 5.3 min to use a straight signalised crossing and avoid using footbridges and underpasses, respectively. Women and older participants were willing to walk longer additional times to avoid those facilities. Participants only avoid crossing the road if the additional time to use straight signalised crossings is at least 20.9 min. The estimated values for the willingness to walk were slightly smaller when using a conditional logit model. The study provides information that is useful for policy decisions about the frequency and the type of pedestrian facilities provided to cross busy roads.

Estimating preferences for different types of pedestrian crossing facilities

In the Decade of Action for Road Safety, the vulnerability of pedestrians to severe outcomes from road crash is well-recognised. This study explored the factors that are influential in pedestrians’ decisions to cross a high-traffic highway in Barranquilla, Colombia, by using a footbridge over the highway, or by cutting across the highway in close proximity to a footbridge. Participants were recruited at each crossing (n = 105 footbridge, n = 105 ground; n = 117 males; M(SD) age = 23.28(5.98) years) and completed a paper survey exploring demographics, highway crossing behaviour, and attitudes regarding the safety and security of the crossing. Despite the majority of participants reporting the ground crossing was dangerous, and that the footbridge crossing was safe, one third of participants never or rarely (approximately 0% and 25% of the time) used the footbridge to cross the highway. Logistic regression revealed that the decision regarding the highway crossing mode (footbridge or ground) was predicted by (a) the frequency in which the footbridge is crossed, (b) the perception of footbridge security in relation to crime, (c) the perception of footbridge safety about traffic conflicts in general, (d) the proximity of the footbridge to the highway ground crossing, and (e) if the subject had experienced an injury during a previous highway crossing. The findings extend our understanding of pedestrian behaviour in crossing highways, not only in relation to the use of footbridges which separate both road user groups, but also ground crossings which place the pedestrians at significant risk especially those in areas with high traffic flow density. Moreover, the findings highlight the complexity involved in improving pedestrian road safety, particularly as the provision of an engineering solution (a footbridge) in close proximity to a high-risk zone (highway) is clearly not the only solution in the much larger road safety system.

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Footbridge usage in high-traffic flow highways: The intersection of safety and security in pedestrian decision-making?

As pedestrians are the most exposed and vulnerable road users to traffic accidents, urban planners frequently propose alternatives to improve their safety. However, some solutions, such as pedestrian bridges and crosswalks at signalized intersections, usually imply longer walking distances compared to the direct crossing alternative which, in its turn, involves a higher risk. In this article, a hybrid framework is proposed to analyse the pedestrians' choice on how to cross an urban road where three crossing options are available: crossing directly, crossing by using a pedestrian bridge or using a crosswalk at a signalized intersection. The decision process is modelled as a discrete choice model incorporating latent variables to consider perceptions and psychological factors, using stated preference data coming from a survey applied in Bogota, Colombia. RESULTS show that the latent variables security/safety and attractiveness of each crossing alternative are relevant to understand the pedestrian crossing behaviour. These latent variables are strongly determined by socioeconomic characteristics of the individual (age, gender, level of study) and conditioned by the circumstances of the trip (main mode of transport, walking or not with children). It was found that a longer walking distance to a pedestrian bridge or a signalized crosswalk increases the probability of direct crossing, having a more relevant effect in the case of the pedestrian bridge.

Manuel Rolong

Papers

Modelling pedestrian crossing behaviour in urban roads: a latent variable approach