Deployment scenarios for speed assistance systems

Speed assistance systems have a strong potential to contribute to solving road traffic problems regarding congestion, energy consumption and safety. However, most speed assistance systems are not yet commercially available, and when they are, large-scale deployment takes a long period of time due to problems, with respect to technology development, user demand, legal issues and market organization. These problems were analyzed by means of scenario analysis and the construction and application of a scenario model. Four scenarios were considered varying in the level of demand for speed assistance and the level of market organization. The analysis and the scenarios indicated that the deployment of speed assistance systems can lead to penetration rates of up to 50 percent in 2025 in case of high market demand and strong market organization. Cooperation among stakeholders is therefore the first and most important step towards a new traffic situation, which is smarter, safer and cleaner than that of today

The accuracy and timing of pedestrian warnings at intersections: the acceptance from drivers and their preferences

The safety of vulnerable road users at traffic intersections is critical. Driver assistance systems can improve safety but have to rely on accurate detection of hazardous situations. Given the complexity of pedestrian movement, detection of pedestrian presence and prediction of their behaviour are not always without error. Drivers' attitude towards such errors is an important issue for the effectiveness of the system. An online questionnaire survey has been carried out to investigate drivers' acceptance of the system under different reliability and accuracy configurations. The results show that safety warnings of pedestrians are generally found to be useful, although false positives and false negatives tend to reduce its pleasantness. The system is found to be most useful for right turn movement at a busy intersection, compared to through movements and quiet intersections. Drivers also find false alarms more acceptable than false negatives. In terms of timing of the warning message, drivers prefer to receive it earlier rather than later

MAVEN Deliverable 7.2: Impact Assessment - Technical Report

This deliverable focuses on an important topic within the MAVEN project - evaluation of the project impact. This is an important step that will allow us to say what the results and impact of the different technologies, functionalities as well as assumptions are. It covers different dimensions of the impact assessment as stated in the Deliverable D7.1 - Impact assessment plan [10]. The field tests proved that the technology in the vehicle works together with the infrastructure and the solution is technically feasible. This was demonstrated also during particular events and is reported in the attached test protocols. At the same time, the emulation and simulation in Dominion software proved the functionality, for example with respect to the cooperative perception or safety indicators. The tests also proved that the key performance indicator "minimum time to the collision" decreases when applying the cooperative sensing. Also, the number of human interventions needed was zero in all the tests. This deliverable also discussed selected results of a detailed user survey aiming at understanding the expected impacts and transition of automated vehicles. The overall number of respondents reached 209. The responses have revealed some interesting facts. For example, over 80% of the respondents believe that CAVs will decrease the number of traffic accidents. Similarly, about 70% of the respondents expect improvements in traffic congestions. Over 82% of respondents declared that they would accept some detour when driving if it helps the overall traffic situation. The literature review, however, indicated that autonomous vehicles will have either a positive or a negative effect on the environment, depending on the policies. For example, opening cars as a mode of transport to new user groups (seniors, children etc.) together with improvements of the traffic, flow parameters can increase the traffic volume on roads. Policy makers shall focus on the integration of the CAVs into a broader policy concept including car or ride-sharing, electromobility and others. In order to evaluate the transition, for example, the influence of different penetration rates of CAVs on the performance, a microscopic traffic simulation was performed. Here the particular MAVEN use cases, as well as their combination, was addressed. The results of the simulation are rather promising. The potential for improvements in traffic performance is clearly there. It was demonstrated that a proper integration of CAVs into city traffic management can, for example, help with respect to the environmental goals (Climate Action of the European Commission) and reduce CO2 emissions by up to 12 % (a combination of GLOSA and signal optimization). On corridors with a green wave, a capacity increase of up to 34% was achieved. The conclusions from this project can be used not only by other researchers but mainly by traffic managers and decision-makers in cities. The findings can get a better idea about the real impacts of particular use cases (such as green wave, GLOSA and others) in the cities. An important added value is also the focus on the transition phase. It was demonstrated that already for lower penetration rates (even 20% penetration of automated vehicles), there are significant improvements in traffic performance. For example, the platooning leads to a decrease of CO2 emissions of 2,6% or the impact indicator by 17,7%

Enhanced Traffic Management Procedures of Connected and Autonomous Vehicles in Transition Areas

In light of the increasing trend towards vehicle connectivity and automation, there will be areas and situations on the roads where high automation can be granted, and others where it is not allowed or not possible. These are termed ‘Transition Areas’. Without proper traffic management, such areas may lead to vehicles issuing take-over requests (TORs), which in turn can trigger transitions of control (ToCs), or even minimum-risk manoeuvres (MRMs). In this respect, the TransAID Horizon 2020 project develops and demonstrates traffic management procedures and protocols to enable smooth coexistence of automated, connected, andconventional vehicles, with the goal of avoiding ToCs and MRMs, or at least postponing/accommodating them. Our simulations confirmed that proper traffic management, taking the traffic mix into account, can prevent drops in traffic efficiency, which in turn leads to a more performant, safer, and cleaner traffic system, when taking the capabilities of connected and autonomous vehicles into account

Cooperative Automated Driving for managing Transition Areas and the Operational Design Domain (ODD)

When cooperative automated vehicles (CAVs) emerge on urban roads, there will be areas and situations where all levels of automation can be granted, and others where highly automated driving will not be allowed or is not feasible. Complex environments or temporary road configurations are examples of situations leading to takeover requests and are referred to as 'Transition Areas'. Such situations are assumed to cause negative impacts on traffic safety and efficiency, in particular with mixed traffic fleets. The TransAID project is developing a digital infrastructure and dedicated traffic management strategies to assist CAVs at transition areas, and preserve safe and smooth traffic flow. This paper explains the relevance of transition areas and the link to the operational design domain (ODD) of automated vehicles. By combining results from different projects with findings from stakeholder consultation workshops, ODD is discussed in detail and a conceptual structure to guide the discussion is provided

Emission optimized control for isolated intersections

Stopping and accelerating at traffic lights is one of the main contributing factors to vehicular emissions in urban environments. The work in this paper demonstrates a generic guideline for minimizing CO2 emissions at traffic lights. This was done using an adaptive control, which uses a cost function for optimization, rather than network-specific control parameters. A new version of the emission model PHEMlight was used, which added of a fuel cut-off mode during coasting and other improvements compared to the previous version. Using this model, it could be determined that the emission optimal ratio between delay time and stops for the cost function of an adaptive control should be 1:4.8. Using this ratio a reduction of 7.6 % of CO2 emissions was achieved compared to a vehicle actuated control

Netwerkmanagement vs. de weggebruiker

Eén doel van netwerkmanagement is om de totale reistijd van het verkeerssysteem te minimaliseren, uiteraard met inachtneming van verkeersveiligheid en luchtkwaliteit. Daartegenover staat de weggebruiker die vooral geïnteresseerd is in het minimaliseren van zijn persoonlijke reistijd. Beide doelen lopen vaak niet geheel parallel. Als vervolg op het hoofdartikel van de afgelopen NM Magazine, over de rol van de weggebruiker, bespreken de auteurs Jaap Vreeswijk en Eric van Berkum de consequenties van deze uiteenlopende belangen

Beleving van wachten bij verkeerslichten

De wachttijdbeleving van automobilisten bij verkeerslichten is een belangrijke maat voor de effectiviteit van een verkeerslichtenregeling. Lage acceptatie, mogelijk met gedragsverandering tot gevolg, kan allerlei onbedoelde neveneffecten met zich meebrengen. In deze bijdrage worden de resultaten van een video-enquête over de beleving en acceptatie van wachten gepresenteerd én vertaald naar concrete toepassingsmogelijkheden

eCoMove: integration of results and conclusions

The eCoMove project developed and analysed several applications aiming to improve fuel economy and reduce emissions. V2X communication is used to connect traffic management and road side units with vehicles and enables information exchange between all participants. The research questions of the project focused on the reduction of fuel consumption, the change of driver behaviour and the impact of the applications on the traffic system. This paper summarizes the main findings of the project and elaborates on the three high level research questions in more detail

Flexible traffic management based on bounded rationality and indifference bands

Constrained cognitive abilities cause imperfections in traveler’s choice behavior which are largely systematic and predictable. This paper introduces the concept ‘regulation flexibility’ to build upon this knowledge, taking it as an advantage to increase the effectiveness of traffic network management rather than a threat. It assumes that within set boundaries, traffic management measures are perceived as acceptable by travelers, enabling road operators to have certain control over behavioral response and undesirable consequences. A conceptual framework for regulation flexibility is provided, following the three stages of the decision-making process: observation, evaluation and choice. Emphasis is on the processes underlying choice and behavior, to explain deviations from rational behavior, rather than the outcome itself. The notion of indifference bands reported in literature is taken as a starting point and applied in a broader context to specify regulation flexibility in all three stages. This paper debates that: (1) travelers’ ability to detect changes in attributes of their trip or the performance of a traffic system is limited, (2) travelers make mistakes in estimating the value of changes, and (3) great diversity in applied choice patterns cannot be explained by observation and evaluation factors alone. In each of the three decision-making stages, multiple aspects are of influence to the perception of travelers and point toward the need for more empirical research. Future research will focus on travelers’ ability to observe changes in attributes of their trip or the performance of a traffic system