A traffic conflict is usually composed of a chain of events in which at least one of the involved road users performs some sort of evasive action to avoid a collision. An evasive action usually involves powerful braking, which leads to sudden, negative change in acceleration (deceleration). The temporal dynamics (variation over time) of the acceleration of a vehicle is represented by the jerk profile. More formally, jerk is the derivative of the acceleration. In the case of an evasive action by braking, the jerk profile is characterized by strong, negative values. This study examined two issues in the quest to understand the benefits of evasive action analysis. The first issue was whether jerk profiles can be used to identify critical traffic events (conflicts). The second issue addressed the validity of the assumption that the deceleration profile is inadequate as a stand-alone measure for conflict identification. Automated video analysis was used to collect traffic data and analysis was applied on two data sets with distinct traffic patterns. The study revealed a significant difference between the jerk behavior of the groups of drivers involved in conflictive and normal traffic interactions. It also showed instances in which automated jerk evaluation was successful in finding conflicts undetected by conventional conflict indicators. The same could not be demonstrated for the road users’ deceleration behavior. These findings support earlier studies on the shortcomings of the use of deceleration data for conflict identification.

Finding a simple and less expensive method to assess and improve sidewalk and corridor conditions in developing countries is essential in order to motivate more people to walk. This study aimed to design and test a method that uses direct observations of driver behavior and street measurements to assess sidewalk and corridor walkability in developing countries. The proposed method includes different walkability indicators related to sidewalk features, crossing facilities, sidewalk facilities, and driver behavior to provide one score that represents the walkability of a sidewalk and one that represents the walkability of a corridor. The method was tested on streets from 10 neighborhoods in the city of Doha, Qatar. The results indicated that the developed method was easy to use and could efficiently measure various indicators, illustrating that it can be used to evaluate corridors with different characteristics to identify and rank areas that require improvement. The study’s findings will provide maintenance agencies, policymakers, and practitioners in developing countries with a simple, efficient, and cost-effective method to evaluate, plan, rank, and improve the walkability of sidewalks and corridors.

Although cycling is increasing in developed regions, such as Europe and North America, high-income developing countries in the Arabian Gulf region still have low cycling activities. Limited research has investigated the barriers to cycling in these countries. In this study, the barriers and motivators in Qatar, a high-income developing country, were investigated. Respondents were asked to report their bicycle usage during the last 12 months. The results indicated that approximately 15% used a bicycle during this period, but only 1.7% bicycled for transportation purposes. The analysis revealed the different barriers to cycling and their relative strengths. The study also compared the perceived challenges of cycling between males and females. The questionnaire results indicated that both groups considered the issues related to the weather conditions, bicycle ownership, lack of paths or connections, and driver behavior as important barriers to cycling. However, the female participants identified clothing, parental consent, and cultural and societal pressure as far more important. When asked about motivators for cycling, the results revealed that improving intersections, adding additional infrastructure facilities, planting trees for shading, affordable bicycles, and campaigns targeting potential cyclists and drivers are needed in order to increase cycling. To better understand how bike-sharing will be perceived if implemented in the future, the feedback was obtained from the participants, and their opinions indicated that there is a great deal of acceptance for this type of service. The outcome of this study can be of benefit to public agencies in developing countries that have the goal of increasing cycling use among their populations.

Distracted driving has been considered one of the main reasons for traffic crashes in recent times, especially among young drivers. The objectives of this study were to identify the distracting activities in which young drivers engage, assess the most distracting ones based on their experiences, and investigate the factors that might increase crash risk. The data were collected through a self-report questionnaire. Most participants reported frequent cell phone use while driving. Other reported activities include adjusting audio devices, chatting with passengers, smoking, eating, and drinking. A structural equation model was constructed to identify the latent variables that have a significant influence on crash risk. The analysis showed that in-vehicle distractions had a high effect on the crash likelihood. The results also indicated that dangerous driving behavior had a direct effect on the crash risk probability, as well as on the rash driving latent variables. The results provide insight into distracted driving behavior among young drivers and can be useful in developing enforcement and educational strategies to reduce this type of behavior.