Shakil Mohammad Rifaat

A logistic model of the effects of roadway, environmental, vehicle, crash and driver characteristics on hit-and-run crashes.

Leaving the scene of a crash without reporting it is an offence in most countries and many studies have been devoted to improving ways to identify hit-and-run vehicles and the drivers involved. However, relatively few studies have been conducted on identifying factors that contribute to the decision to run after the crash. This study identifies the factors that are associated with the likelihood of hit-and-run crashes including driver characteristics, vehicle types, crash characteristics, roadway features and environmental characteristics. Using a logistic regression model to delineate hit-and-run crashes from nonhit-and-run crashes, this study found that drivers were more likely to run when crashes occurred at night, on a bridge and flyover, bend, straight road and near shop houses; involved two vehicles, two-wheel vehicles and vehicles from neighboring countries; and when the driver was a male, minority, and aged between 45 and 69. On the other hand, collisions involving right turn and U-turn maneuvers, and occurring on undivided roads were less likely to be hit-and-run crashes.

Severity of motorcycle crashes in Calgary

Motorcycle riders would be more vulnerable in the event of a crash because of their lack of protection which would often result in them suffering more severe injuries than car drivers. This paper estimated three crash severity models to identify factors that contributed to increasing the severity of motorcycle involved crashes in the Canadian City of Calgary. We found that results from the ordered logit model, heterogeneous choice model and partially constrained generalized ordered logit model produced estimates that were very similar which attested to their robustness. Injury severity tended to increase in neighborhoods with loops and lollipops types of streets or involved right-angle and left-turn-across-path crashes, a truck, unsafe speed or alcohol use but tended to decrease if the crash occurred in parking lots or during winter, involved a van or male rider, or a rider following-too-closely to the vehicle in front.

Effects of Street Patterns on Injury Risks in Two-Vehicle Crashes

Road crashes not only claim lives and inflict injuries but also create an economic burden on society because of lost productivity. Many studies have identified factors affecting the frequency and severity of crashes. However, few, if any, studies have explored the effect of street pattern on injury risks in urban crashes. In this study, street pattern or urban form is classified into four categories: gridiron, warped parallel, loops and lollipops, and mixed patterns. Their effects on injury risk are examined together with other factors including road features, drivers’ characteristics, crash characteristics, environmental conditions, and vehicle attributes. Calgary, Alberta, Canada, is chosen as the case study, and the logistic regression model is applied with reported crash data from 2003 to 2005 to investigate various factors. The results suggest that current popular patterns, including the loops and lollipops design, are safer than the conventional gridiron pattern from an injury risk perspective in the event of a crash.

Effect of Street Pattern on Road Safety: Are Policy Recommendations Sensitive to Aggregations of Crashes by Severity?

In the past 50 years, the loops-and-lollipops design has become the basic building block of many urban neighborhoods. In the field of traffic engineering, this combination of cul-de-sacs and loop streets is designed to discourage through traffic and improve road safety, and thus it has the support of many traffic engineers. Perhaps because of its intuitive appeal, few studies have examined the impact of this design on road crashes. The city of Calgary, Alberta, Canada, was used as a case study to examine the effects of neighborhood street patterns on the number of reported crashes. In the study, crashes were converted into equivalent property-damage-only crashes using various weighting factors to check the sensitivity of the finding. Results suggest that currently popular road patterns such as warped parallel, loops, and lollipops are safer than the traditional gridiron pattern. Moreover, this result is quite robust regarding severity weights or aggregation schemes, albeit with some variations in the absolute values of the estimated effects. However, changing the aggregation scheme had a significant effect on some of the control variables used in the model, especially the socioeconomic characteristics, although most of the road features and land use estimates remained robust.

Effects of Neighborhood Street Patterns on Traffic Collision Frequency

Over the last 50 years, the loops and lollipop design has become the basic building block of many urban neighborhoods. In the field of traffic engineering, this combination of cul-de-sacs and loop streets is designed to discourage through traffic and improve road safety and thus has the support of many traffic engineers. Perhaps due to its intuitive appeal, few studies were conducted to examine the impact of this design on road crashes. Using the City of Calgary in Canada as a case study, this study examines the effects of different neighborhood street patterns on the number of reported crashes. Our results suggest that currently popular road patterns such as warped parallel, loops and lollipops, lollipops on a stick, and mixed shapes are associated with fewer crashes than traditional gridiron pattern.

Urban Street Pattern and Pedestrian Traffic Safety

This study examined the effect of different urban street patterns on vehicle-pedestrian crash severity. Pedestrian crash data for the City of Calgary for the years 2003–2005 were used to estimate a partially constrained generalized ordered logit model. Besides street pattern, many variables related to drivers, road, environment and traffic characteristics were used as control variables. The results indicated that currently popular urban street patterns, like loops and lollipops design, were found to be associated with higher pedestrian crash severity, when compared to the traditional gridiron pattern.

Urban design and planning influences on the share of trips taken by cycling

Abstract This study examines the effect of different street pattern, road infrastructure and other physical attributes on the share of bicycle trips in a community area. Using the 2011 census data and the road infrastructure data of Calgary city, the study finds that different street patterns have significant effects on bicycle usage and thus, should be considered in the development of new communities for promoting active transport. Also, increases in the percentage of green space (agricultural and park areas) and semi-detached houses are associated with greater bicycle use, whereas an increase in the number and/or size (area) of road intersections is associated with reduced bicycle use relative to other modes of transport.

Vehicle-Pedestrian crashes at Intersections in Dhaka city

© Rifaat et al.; Licensee Bentham Open This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License. Background: Pedestrians are some of the most vulnerable road users, especially in large congested cities in developing countries. In order to develop appropriate countermeasures to improve safety, research has to be conducted to understand the factors contributing to vehicle-pedestrian collisions. Objective: This study aims to identify the factors contributing to intersection crashes in a developing country context. Method: A Poisson regression model was applied to police reported crash data from the capital of Bangladesh, Dhaka. Results: This study finds that an increase in vehicle traffic and the presence of police officer, footbridge, bus stop, solar panel and waste deposit facility were associated with an increase in the number of vehicle-pedestrian crashes, whereas an increase in pedestrian volume, roads with the same number of inbound and outbound lanes, roads with greater number of lanes, and the presence of traffic signal, commercial area or offices, speed breaker and rail crossing were associated with a reduction in the number of vehiclepedestrian crashes. Conclusion: While the results of most traffic and engineering factors are consistent with those obtained in previous studies in developed countries, some of the results on human related factors and unusual road furniture are atypical and require more locally targeted countermeasures.