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Modern urban mobility needs new solutions to resolve high-complexity demands on urban traffic-control systems, including reducing congestion, fuel and energy consumption, and exhaust gas emissions. One example is urban motorways as key segments of the urban traffic network that do not achieve a satisfactory level of service to serve the increasing traffic demand. Another complex need arises by introducing the connected and autonomous vehicles (CAVs) and accompanying additional challenges that modern control systems must cope with. This study addresses the problem of decreasing the negative environmental aspects of traffic, which includes reducing congestion, fuel and energy consumption, and exhaust gas emissions. We applied a variable speed limit (VSL) based on Q-Learning that utilizes electric CAVs as speed-limit actuators in the control loop. The Q-Learning algorithm was combined with the two-step temporal difference target to increase the algorithm’s effectiveness for learning the VSL control policy for mixed traffic flows. We analyzed two different optimization criteria: total time spent on all vehicles in the traffic network and total energy consumption. Various mixed traffic flow scenarios were addressed with varying CAV penetration rates, and the obtained results were compared with a baseline no-control scenario and a rule-based VSL. The data about vehicle-emission class and the share of gasoline and diesel human-driven vehicles were taken from the actual data from the Croatian Bureau of Statistics. The obtained results show that Q-Learning-based VSL can learn the control policy and improve the macroscopic traffic parameters and total energy consumption and can reduce exhaust gas emissions for different electric CAV penetration rates. The results are most apparent in cases with low CAV penetration rates. Additionally, the results indicate that for the analyzed traffic demand, the increase in the CAV penetration rate alleviates the need to impose VSL control on an urban motorway.

International audience; Urban strolls allow to intercept the atmospheres of a space, mediating between the moving body and the context. With a situationist approach, I carried out an exploration of the sprawlscape along the SS554, the urban motorway connecting Cagliari (Italy) and its surrounding centers. The contexts I met, a particular fusion of rural and urban, are considered marginal and degraded compared to the city, thus the choice of exploring on foot, driven by the difficulty that these spaces pose to walking and the possibilities it allows to explore spaces atmospherically. The stroll was integrated by a photoreport called « flatshades » : photography is a useful medium to explore and interprete the atmosphere of a space, and it allows the (re)presentation and sharing of this personal perceived atmosphere.

Over the last years, distracted driving possesses a leading position among accident causes and it constitutes an increasing road safety problem with disastrous results. Considering external factors of distraction as highly significant, they can be grouped in four categories: built roadway, situational entities, natural environment, and built environment. The fourth category, related to civil infrastructure and commercial land use, combined with high vehicle speeds that occur in motorways, might contribute to the creation of a very dangerous environment, increasing driver distraction and inattention. Through accurate research, solid results can emerge and traffic safety can be enhanced. The present study deals with driver distraction caused by out-of-the-vehicle factors, as well as factors related to the driver, such as age, gender, driving experience etc. It covers the distraction of driver attention during driving due to external factors that are not related to the main task of driving, resulting in impairments to driver attention and decision-making ability and hence the driver’s overall performance. For this purpose, we assess the side effects of numerous road elements, such as information signs, roadside advertising, Variable Message Signs, toll buildings, noise barriers/panels etc. to driver attention. The study is based on a medium-scale experimental procedure which took place in Attica Tollway, the Ring Road of the Athens metropolitan area, which was part of a larger research project conducted by the University of Thessaly, Department of Civil Engineering that included a total of three urban freeways in Greece. In order to create the appropriate research basis and to use as reliable data as possible, the gaze tracker FaceLab software was used on a sample of 29 drivers. Each participant drove 51 km on Attica Tollway, both in level terrain with 3 lanes and speed limit up to 120 km/h and in rolling terrain with 2 lanes and speed limit up to 80 km/h. The distraction of driver attention is evaluated via a continuous recording of his/her gaze, which acts as the main indicator regarding driver performance. The results of this procedure, analyzed via Captive software, are focused on the time that the driver’s gaze remained on each of the road elements under research. The analysis offers conclusions on different aspects - driver, road element and the road in total - comparing and categorizing the results by using a 4-level timescale from 0 to 2 seconds. This study can be used as a tool that can help in understanding and limiting the use of roadside elements that are not related to the execution of the driving task, but that may serve as potential causes of distraction. The results of this type of research procedures are very useful in preventing the forthcoming pressure for more billboards and trademarks on the roads, as well as in encouraging the adaptation of more precise regulations relating to the road infrastructure, the placement of roadside elements, etc.

In recent years, several studies show that people who live, work or attend school near the main roadways have an increased incidence and severity of health problems that may be related with traffic emissions of air pollutants. The concentrations of near-road atmospheric pollutants vary depending on traffic patterns, environmental conditions, topography and the presence of roadside structures. In this study, the vertical and horizontal variation of nitrogen dioxide (NO2) and benzene (C6H6) concentration along a major city ring motorway were analysed. The main goal of this study is to try to establish a distance from this urban motorway considered “safe” concerning the air pollutants human heath limit values and to study the influence of the different forcing factors of the near road air pollutants transport and dispersion. Statistic significant differences (p = 0.001, Kruskal–Wallis test) were observed between sub-domains for NO2 representing different conditions of traffic emission and pollutants dispersion, but not for C6H6 (p = 0.335). Results also suggest significant lower concentrations recorded at 100 m away from roadway than at the roadside for all campaigns (p < 0.016 (NO2) and p < 0.036 (C6H6), Mann–Whitney test). In order to have a “safe” life in homes located near motorways, the outdoor concentrations of NO2 must not exceed 44–60.0 µg m-3 and C6H6 must not exceed 1.4–3.3 µg m-3. However, at 100 m away from roadway, 81.8% of NO2 receptors exceed the annual limit value of human health protection (40 µg m-3) and at the roadside this value goes up to 95.5%. These findings suggest that the safe distance to an urban motorway roadside should be more at least 100 m. This distance should be further studied before being used as a reference to develop articulated urban mobility and planning policies.

Relations between the occurrence of road accidents, traffic and rainfall conditions are valuable in setting safety objectives for traffic management, and in assessing the safety impacts of new traffic management systems, prior to their implementation. Based on traffic, road accidents and rain data collected over one year, on a French urban motorway network, a set of safety performance functions were estimated; each of them provides the accident risk per vehicle-kilometer for a certain type of accident, according to the occurrence of rain, and to the level of a traffic variable (average speed, occupancy, percentage of tailgating...). Analyses were carried out separately by lane and for two types of accidents: single-vehicle accidents and multiple-vehicle accidents.The relationships, although statistically significant, have yet to be validated by the treatment of another set of accidents.

This report provides a diagnostic and a set of recommendations for the coordination of infrastructure investments in three main sectors in Romania: roads; water and wastewater; and social infrastructure (education, health, culture, and sports). The proposals formulated are targeted primarily at the main client of this work, the Ministry of Regional Development and Public Administration (MRDPA) and specifically at the Directorate General for Regional Development and Infrastructure (DG RDI), which manages the most important state-budget-funded program for local infrastructure investments – the National Local Development Program (PNDL). Other key stakeholders include the Center of Government (CoG), the Ministry of Public Finances, the Ministry of European Funds, other central authorities in charge of EU and/or state-funded investment programs, Regional Development Agencies, and county and local councils. While customized for the PNDL, the recommendations that follow can be replicated across all state-budget-funded investment programs. This report presents multiple instruments for promoting coordination: dedicated platforms, harmonization of investment programs (design, financing criteria, producers), and knowledge sharing of good practices at the local level.

EWGT 2015-Euro Working Group on Transportation, DELFT, PAYS-BAS, 14-/07/2015 - 16/07/2015; The purpose of this paper is to study the link between the occurrence of injury road accidents, the prevailing traffic conditions, and the occurrence of rain. This is useful for assessing, before its implementation, the safety impact of a new traffic management. Traffic conditions were extracted from a one year traffic database which covers 150 kilometres of two or three lanes urban motorways near the city of Marseille, in the south of France. 208 loop detectors provide the individual speeds, headways, arrival times and lengths of vehicles. Based on this information, thirteen aggregated traffic variables were constituted every six minutes, such as the average speed, occupancy, short time headways and a few combinations of speed, relative speed and time gaps. 292 injuries or fatal accidents occurred on the network during the same year. The French accident database provides their characteristics - location, time and type of accidents, meteorological conditions and other parameters addressing the infrastructure, the driver and the vehicle. The rain occurrence is provided, every six minutes, from a meteorological station. A set of safety performance functions were estimated, each one giving the risk of injury accident by vehicle-kilometre according to the level of one traffic variable and according to the occurrence of rain. Generally based on logistic regression models, analyses were carried out separately by lane and for two types of accidents -single vehicle accidents and crashes between vehicles. Some relations linking accidents with traffic variables are significant: the occurrence of single vehicle accidents is related to the speed on the fast lane; the occurrence of multiple vehicle accidents is related to occupancy.