Shalom Hakkert

Scenario building as a tool for planning a sustainable transportation system

Abstract Identifying policies that will result in a sustainable transportation system is a major challenge for policy makers since it involves a high level of uncertainty regarding the future effect of a given policy package on the transportation system and the urban environment. In this paper, we suggest and use a scenario approach to explore the future development of the Tel-Aviv Metropolitan Area (TAMA). We have constructed two scenarios for the future development of the TAMA: an expected scenario and a desired scenario. The scenarios were constructed by means of a two-round Delphi expert-based survey. Based on the opinion of the experts, our research examines the potential policy measures, which may contribute to a sustainable transportation system in Tel-Aviv. The development of both expected and desired scenarios helped to analyze the feasibility of the desired scenario and assess the likelihood of implementation of its different elements. According to the results, the key elements in the desired scenario are a highly developed public transport system, better coordination between the spatial development and the transportation system, high parking fees, congestion pricing and maintaining the functional role of the Central Business District area. The expected scenario shares many common elements with the desired scenario, which is considered a positive result.

Impact of Active Speed Limiters on Traffic Flow and Safety: Simulation-Based Evaluation

Speed limiters, which control the maximum speeds of vehicles so equipped, have been proposed in recent years as speed management tools. A simulation-based evaluation is described of the impact of a wide installation of speed limiters on traffic flow characteristics and on safety. Microscopic traffic simulation is used; it models the driving behavior of individual vehicles in detail and so captures not only the impact of speed limiters on equipped vehicles but also the interaction between equipped and unequipped vehicles and the resulting impact on the latter. In the experiment, the impact is evaluated of preset speed limiters for two limiter-set speeds, 100 km/h and 120 km/h, at various desired speed distributions and congestion levels. The simulation results show that speed limiters can reduce average traffic speeds up to 10% and that the variability of traffic speeds may also be lowered. Consequently, a significant reduction in accident rates might be achieved.

The influence of shoulder characteristics on the safety level of two-lane roads: A case-study

Constructing proper shoulders may improve road safety on two-lane roads. Previous research reported crash reductions following shoulder widening. This study aimed to examine the relationship between shoulder characteristics and crash occurrences on two-lane rural roads in Israel. The study database combined information on crash numbers, traffic volumes and road infrastructure characteristics of 3594 road sections. To examine a relationship between shoulder characteristics and crashes, given other road characteristics, two types of statistical models were developed: case-control and negative-binomial regression models, for several crash types. We found that the impacts of shoulder width and other road characteristics on crashes were generally consistent across various models and crash types, where a non-monotonous link between the shoulder width and crashes was typically observed. For various crash types, the models showed an increase in crash risk with an initial extension of the total shoulder, up to 2.2 m, and a consequent decrease in crashes with a further shoulder widening, over 2.2 m, by 2-6% and 1-4%, respectively, for each 0.1 m of shoulder extension. An increase in the width of unpaved shoulders, over 0.9 m, was associated with increased crash risk, in injury and total crashes, by 5% for each 0.1 m of shoulder extension. Lowest crash risks were found for total shoulder widths of about 3 m or more, but also for narrow total shoulders, below 1 m. Conversely, medium total shoulders, of 1.8-2.4 m in width, and unpaved shoulders of over 1 m, were associated with an increase in crash risk and, hence, are not recommended for use. The tools developed in the study may assist in decision-making during the design stages of a new road or upgrading existing road sections, on two-lane local roads.

Exploring patterns of child pedestrian behaviors at urban intersections

Children are more vulnerable as pedestrians due to their cognitive, physical and behavioral traits. However, walking is one of the main forms of travel for children, particularly during leisure hours. Child pedestrian injury primarily occurs in urban areas, with a significant share at crosswalks. This study observed child pedestrian behaviors at crosswalks of urban intersections aiming to characterize their behavior patterns and identify risk factors that may lead to injury. Crossing behaviors of children and adolescents up to age 18, during leisure hours, were video-recorded at 29 crosswalks, on signalized and un-signalized intersections situated on collector roads. Some children used pedestrian crosswalks while riding a bicycle or other non-motorized means; they were also included in the sample. Behaviors of 2930 young road users were encoded and compared by age groups. Multivariate logistic regression models were adjusted to identify factors associated with crossing on red and with non-checking vehicle traffic at un-signalized crosswalks. The findings pointed to different behavior patterns for the various child age groups. Risk-taking behaviors are higher for older children; adolescents aged 14-17 cross more on red, without checking traffic, outside crosswalk boundaries and while distracted. At all types of sites, a fifth of children over the age of 9 crossed by riding, the probability of crossing on red and of non-checking traffic prior to crossing at an un-signalized crosswalk was higher for children riding an electric bicycle or kick-scooter. The non-checking of traffic was also higher when a child is distracted by a mobile phone or other electronic gadget, or carries a big object. Children under age 9 were usually accompanied by adults but still exhibited risk-taking behaviors that apparently mirrored those of the adults. Risk-taking behaviors of young road users should be taken into account in the development of injury prevention programs focusing on child and parent education and training, and by adapting the urban environment to better meet their needs.

Exploring safety impacts of pedestrian-crossing configurations at signalized junctions on urban roads with public transport routes

ABSTRACT This study explored the impacts of pedestrian-crossing configurations and other design features, on accident occurrences at signalized junctions situated on central public transport routes (PTRs) of urban arterials. Statistical tests and negative-binomial regression models were applied to identify factors affecting accidents and to examine accident numbers of the PTR junctions as opposed to comparison-sites. At the PTR junctions, a consistent impact of pedestrian-crossing configurations on accidents was found, where a gradated-crossing with mixed-shifting is the least safe. Four-legged junctions tend to higher accident numbers relative to the three-legged junctions. PTR junctions are characterized by higher accident numbers, related to comparison-sites, when controlling for other design characteristics. The study findings may assist in selecting preferable design solutions while planning PTR.

Scenario Building for the Future of the Tel Aviv Metropolitan Area and Its Transportation System Using the Delphi Method

Tel Aviv is the largest metropolitan area in Israel and serves as the country’s main financial and cultural centre. The Tel Aviv Metropolitan Areal stretches over 1,475 square kilometres and is inhabited by 2.6 million people, of which 90 percent are living in urban areas. Data from 1999 show that the Tel Aviv Metropolitan Area produced 50 percent of the GDP and was responsible for 46.4 percent of the jobs in Israel. Because of its geographical position and for historical reasons, the Tel Aviv Metropolitan Area is a transportation focal point. All traffic between the north and the south of Israel, as well as traffic connecting the main cities (Jerusalem, Tel Aviv, Haifa and Beer Sheba) to each other, must pass through the Tel Aviv Metropolitan Area. Thus, the metropolitan transportation infrastructure must fulfil two major functions: a) supply the demand for transportation on the national level; and b) supply the demand for transportation within the metropolitan area on the regional and local levels.