Optimal traffic calming: A mixed-integer bi-level programming model for locating sidewalks and crosswalks in a multimodal transportation network to maximize pedestrians’ safety and network usability

We study the effect that installing sidewalks and crosswalks, as traffic calming facilities, has on the safety and usability of a transportation network with automobile, public transit and walking as modes of transportation. A mathematical programming model is proposed for this problem whose objective is to minimize the safety hazard for pedestrians and the total transportation cost of the network. We utilize a customized greedy heuristic and a simulated annealing algorithm for solving the problem. The computational results indicate that installing sidewalks and crosswalks at proper locations can reduce the overall transportation cost and improve pedestrians’ safety.     

Operationalization of path walkability for sustainable transportation

Most walking travel behavior research thus far has tested area-based neighborhood walkability, which is measured with meso-level urban form attributes. In need of micro-level walkability analyses that focus on individual travelers and their routes, we propose a route-oriented linear walkability concept named “path walkability.” It is defined and measured by 42 path walkability indicators that can collectively represent an individual traveler's micro-level walkability. A graphic measurement instrument for an objective and efficient on-field walkability measurement is developed. This study also sets the protocol for quantitatively integrating the walkability data measured at the segment level into path walkability indicators that are comparable at the route level. To test the applicability of the proposed path walkability, a pilot case study is conducted within a station area. A user survey is administered to collect transit users' access mode choices and walking routes to the station. The survey results help identify two groups of street segments: one used by regular walkers and the other selected by habitual auto users/occasional walkers. The routes chosen by the two groups are quantitatively and graphically compared for walkability. The analyses show a physically measurable and quantitatively comparable difference between the routes' walkability and suggest criteria for walking-conducive transit walkability for station users. Specific design recommendations for improving street-level micro-walkability for future transit-oriented developments (TODs) are added along with a future research agenda.     

A comparison of three methods for assessing the walkability of the pedestrian environment

This paper presents the results of a research project conducted in the UK designed to increase understanding of the factors which influence levels of walking and pedestrian route choice. It describes a number of techniques that were used to assess the pedestrian environment from a pedestrian’s perspective. These techniques included a computer based tool developed using stated preference surveys to determine the relative values of a range of factors in the pedestrian environment; an on-street survey that was designed to investigate values and attitudes towards different attributes of the pedestrian environment along a route; and finally an ‘on the move survey’ where pedestrian volunteers were interviewed while walking along the route in order to get an actual account of their experiences as they walk. A case study is then used to show the benefits and disadvantages of using these different techniques and compares results for a pedestrian route in the City of Leeds in the UK. The results indicate that there were a number of pedestrian attributes considered important by pedestrians when walking including pavement cleanliness, safe crossing places, good connectivity and sense of security. The three approaches complement one another and have highlighted in different ways that the walking experience is affected by the cumulative impact of multiple interactions (both positive and negative) as people walk in the pedestrian environment.