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Road traffic safety is a crucial global objective. It is important for every country to review and improve road safety policies and strategies, based on an objective understanding of its own road traffic safety situation in the world. With the aim of contributing to such a review and understanding, this study conducted a multi-country survey to gather information about various facts related to legislation, enforcement, and education, which are designed to achieve safer drivers in nine countries, by using a common format. This paper introduces the results of the survey with a particular focus on legislation and enforcement regarding speed limit violations and red-light-running as well as on education within the driving licensing systems. It highlights variations, in terms of penalty settings and enforcement levels, in different countries; it also examines the training durations necessary for acquiring a driving license and license renewal procedures. In this way, it demonstrates the potential and significance of understanding the relative position of each country in terms of road traffic safety through an international comparison despite its limited information. This work was supported by the International Association of Traffic and Safety Sciences (IATSS). The authors are grateful to the members of IATSS's project for their valuable comments on our survey and results and Politecnico di Milano, Politecnico di Torino, Regione Lombardia in Italy, Prof. Axel WOLFERMANN of Hochschule Darmstadt in Germany, Eng. Mustafa Almallah of Qatar Transportation and Traffic Safety Center, Junjie Zhou of Tongji University in China, and Sushreeta Mishra of the University of Manitoba in Canada for their contributions to data collection.

Design-hour volume (DHV) and directional DHV (DDHV) are important traffic forecast parameters for both planning and operational studies. They are used for roads and intersection design and operational analysis. Estimating these two parameters requires a record of hourly volumes for every hour in a year. Therefore, permanent traffic counters are usually used to keep a record of those hourly volumes. The use of permanent counters faces several challenges because of adjacent construction activities and hardware or communication failure. These challenges result in the missing part of the collected data. Moreover, estimating DHV and DDHV based on short-term traffic counts is often needed. In this research, an artificial intelligence approach is used to estimate DHV and DDHV for roadways with different functional classifications. An artificial neural network model, which utilises historical records of annual average daily traffic along with other road characteristics, such as number of lanes and functional classification, is developed. Results show that the model was able to achieve a highly accurate and reliable DHV and DDHV estimates.

Analytical macroscopic models are presented to quantify delay at signalized intersections for extended control periods (multiple cycles) attributable to downstream time-variable congestion. Each of the models consists of an upstream demand estimation algorithm, a downstream queue build-up prediction algorithm, a shockwave propagation and dissipation tracking algorithm, and an algorithm that carries traffic aftereffect of a cycle’s control into the following cycle. Model inputs are basic traffic flow properties, signal control parameters, and link geometry. The models are modular and can be incorporated into any size system for one or multiple cycles. The models were tested on a hypothetical system of closely spaced intersections and under different traffic flow, control, and geometric conditions. Results show that delay induced by downstream traffic operations on an upstream intersection can be significant and that it may change with time and reach steadiness once traffic flow, downstream queues, and signal control measures stabilize and start replicating over time. Green ratios of neighboring intersections exert a significant influence on delay. For certain green ratios and geometric combinations, offsets can exert appreciable influence as well. The delay values and their temporal variation compared well with those from a microscopic simulation model.

Background Transit oriented developments (TOD's) are a type of urban development that emphasize diversity in land use and concurrence of more sustainable modes of transport. Particular emphasis in TOD is given to active (Waling and Cycling) and semi-active (Transit) transport modes. The aim of the study is two-fold: demonstrates the advantages of transit-oriented developments including benefits to public health, and demonstrate a suitable analysis framework and structure for conducting similar studies. Methods A residential area at the outskirts of Dubai is used as a case study. Travel demand forecasting models were used to estimate changes in trip generation, distribution, mode choice, and route assignment brought about by the relocation of destinations. To account for normal variation and uncertainty, three travel mode choice shift scenarios and corresponding changes in distances walked and cycled were estimated based on published rates, local conditions and culture. Changes were mapped to health, environmental, energy, and economic benefits. On health, reductions in obesity, high blood pressure and high blood cholesterol, and heart attach were estimated based on published rates. Economic benefits (reduced mortality) were evaluated using HEAT (Health Economic Assessment Tool). Aggregate reductions in energy consumption, carbon dioxide emissions, travel time and operating costs (of private vehicles) were all estimated. Health benefits due to reductions in pollution were not estimated. Results A framework quantifying the health benefits of TOD was proposed and implemented. Travel demand changes were mapped to health benefits. The walk/cycle plus transit (to reach destination) scenario and yearly benefits due to reduced mortality was $1,797 and $8,343 for the conservative and optimistic scenarios, respectively; for the Walk/Cycle the values are $10,973 and $50,941. That a specific amount of health-induced economic gain may be estimated in conjunction with TOD's using the proposed framework is the more relevant outcome. Conclusions Estimating health gains, environmental improvements, and economic benefits of TOD implementation were possible using standard travel demand forecasting models. Mapping travel changes to health and other benefits is key to quantifying different benefits of TOD's. Normal variation and uncertainty precipitated by variations in policies, local environments and cultures may be accounted for by considering a range of scenarios.

Background Urban roadway intersections are key components of urban transportation networks. They are traditionally viewed and designed as primarily motorized-traffic facilities thus their physical and operational designs aimed at maximizing traffic throughput. Seen from a systems’ viewpoint, however, they are transport and community facilities with direct and indirect impacts on traffic functionalities, public health and the livability of communities. Thus, an integrated physical and operational design approach is necessary to design and/or analyze those intersections. Methods This study proposes a new methodology for measuring intersection performance called the Holistic Intersection Rating System (HIRS). It is based on design and technology innovation to improve operations and foster public health and community well-being. HIRS will assess the intersection design and functionalities with respect to two main categories: enabling technologies and physical design aimed at the transport functionality, and physical design and operability aimed at public health and community well-being. In particular, HIRS examines transportation intersections as system components of the urban environment. It rates the physical features of the road and the different motorized and non-motorized traffic flow design and operation parameters that equitably optimize throughput and support desired public health and community well-being outcomes. The public health and community well-being outcomes HIRS rates relate to physical and mental health, community severance, and “completeness” of intersections. Results HIRS facilitates pedestrian and cyclists’ use of intersections so intersections serve the dual needs of meaningful travel and good health while improving drivers experience and neighborhood livability and quality of life. The HIRS index may be constructed using common intersection travel efficiency and public health and community well-being indicators or indicators. The indicators can be weighed using two methodologies: the Relative Importance Index (RII) and the Analytical Hierarchy Process (AHP). The proposed system will be validated using an interdisciplinary industry panel of experts, and with empirical theoretical data runs. Conclusions Physical and operational design of roadway intersections, and the rating of sufficiency of such designs, are both necessary and possible for the well-functioning and use of urban transport systems and their users irrespective of modality. Tools that are dynamic and accommodating of changing designs and community values and priorities are necessary.

This paper presents a procedure for dynamic design and evaluation of traffic management strategies in oversaturated conditions. The method combines a dynamic control algorithm and a disutility function. The dynamic algorithm designs signal control parameters to manage formation and dissipation of queues on system links with explicit consideration of current and projected queue lengths and demands. The disutility function measures the relative performance of the dynamic control algorithm based on preset system performance goals. The user may statically select the management strategy, or alternatively the system may be instructed to set off different management schemes based on predefined performance thresholds. The problem was formulated as one of output maximization subject to state, control, and traffic management strategy choices. Solutions were obtained using genetic algorithms. Four traffic management plans were tested to show the capabilities of the new procedure. The results show that the procedure is able to generate suitable signal control schemes that are favorable to attaining the desired traffic management goals. The results showed that multiple, or hybrids of single measures of effectiveness may need to be examined in order to correctly assess system performance. The procedure has potential for real-time implementation in an intelligent transportation system setting.

This paper demonstrates the feasibility of an advanced concept of traffic control for congested urban arterials in an intelligent transportation system (ITS) setting. The core idea of the new concept is to integrate the capability of dynamic adaptive signals with dynamically optimized time-dependent variable speed. Under such control, speeds would be automatically optimized and set by a central computer in parallel with the other signal control parameters. Speed and signal control parameters would change between links and over time, in response to changing traffic conditions. Drivers would follow the optimized speed as they enter a link. Once an optimal speed has been set for a link, it remains constant until the control cycle ends. Link speeds would be updated only at the end of every control cycle. The control cycle may change in length as system conditions evolve. The new control concept was tested on a congested arterial with multiple links. The arterial system was modeled as a discrete event time var...

Background In the context of city operations and management, smart generally implies“…turning to technology to better connect our communities, improving citizen services”, and, more importantly, finding more intelligent ways to manage city resources and assets. It is a common notion that a city transportation system is a critical asset that must be intelligently managed to enable a better quality of life. It is less clear, however, that a city transportation system is in fact a public health tool and enabler. A transportation system, though, is not just the physical system it is; it is the integration of several activities some of which involve physical assets while other involve policies, standards and norms, that take place over long time span and involve significant resources including technology. Catering for public health should be an integral part of the smart city movement and thinking. Methods The paper first examines the different activities involved in putting together a transportation system, namely: Planning, Design, construction, Operations (management), Maintenance, and, in some cases, Decommissioning (henceforth PDCOMD), and then maps those activities to known public health outcomes. The paper notes that certain activities of the transport system development process are more suited to serve public health than others. For one, transportation system planning is fundamental to ensuring suitable integration of public health in the early stages of putting the transport system together. The operations activity is equally critical but historically—and to this day-- seldom viewed or used as the public health tool it is. Results This paper shows that “smart” as in integration of information and communication technology to improve efficiency of the transportation system may or may not serve public health; public health considerations in some cases require the calming/slowing down and spatial shifting-- thus the appearance of inefficiency-- of certain elements of the transportation system. Alternatively, the notion of efficiency as applied to transportation systems may need to be modified to explicitly incorporate aspects of public health. Conclusions The now trendy notion that information sensing, connectivity, and computation form the backbone of smart cities is questioned. The paper presents an alternate framework where public health is made integral to the notion of smart cities through explicit consideration and integration in key transportation system activities. Adopting an encompassing definition of “health” and “healthy” is vital. Among the many transport system activities, the paper identifies two, planning and operating, where public health consideration is particularly consequential.

Background In the context of transport systems, traffic congestion is always presented as an operational issue with negative socio-economic impacts. Rarely in engineering research and curricula is congestion portrayed as a public health issue-- a stress causing factor-- as in fact it is. It is accepted in the public health domain that repeated and prolonged driving in congested traffic conditions is a form of chronic stress and a serious health risk. Managing stress in difficult traffic conditions is a multifaceted activity in which proper traffic control can play a significant part. Methods This papers presents the human health side of traffic congestion and connect that to known and quantifiable traffic phenomena that, for modeling purposes, may be used as stress markers. Traffic control can thus be optimized with explicit consideration of stress. A case of a "health-sensitive" control algorithm for congested signalized systems is presented where control parameters are optimized to explicitly reduce the occurrence and intensity of unhealthy stress-inducing traffic conditions. The traffic signal control algorithm is formulated as a dynamic signal dynamic speed controller that directly and explicitly reduces the known stress-inducing operational traffic conditions. Results The resulting controller is combinatorial optimization problem. The control decision variables are traffic signal control parameters and network link speeds. Genetic Algorithms were used to solve the optimization. The results show that the signal and speed control generated markedly improved traffic flow where stress-inducing conditions were either eliminated or significantly reduced. Conclusions As extended and long-term exposure to congestion and difficult traffic conditions is a documented stressor with negative long term health impacts, current methods of signal control need to be modified to explicitly consider and minimize the impact of known stress-inducing traffic conditions.