European Transport Research Review

The critical and follow-up headways are the two gap-acceptance parameters which explain the traffic interaction of a minor street vehicle when enters the roundabout, merging into or crossing one or more circulating (major) streams. Several studies and researches provide measurements of critical and follow-up headways from real data at roundabouts. The objective of our research is to synthesize the data from the series of selected studies to interpret variation across the studies. In order to match the research goal, a systematic literature review on estimations of critical and follow-up headways at roundabouts was undertaken. Since several studies and researches developed worldwide were examined, we were able to note that the effect size varied from study to study. Thus the meta-analysis of effect sizes was performed as part of the literature review through the random-effects model. After discussing the assumptions of this model, the dispersion in effects across studies was assessed and the summary effect for each of the parameters under examination was computed. Calculations were made both for single-lane roundabouts and double-lane roundabouts, as well as for turbo roundabouts. Compared to the results of individual studies, the single (quantitative) meta-analytic estimate provides an accurate and reliable synthesis on the specific issue here addressed, and gives, with greater power of the individual reviewed studies, a comprehensive measure for the parameters of interest.

Aeronautic transport has an effective necessity of reducing fuel consumption and emissions to deliver efficiency and competitiveness driven by today commercial and legislative requirements. Actual aircraft configurations scenario allows envisaging the signs of a diffused technological maturity and they seem very near their limits. This scenario clearly shows the necessity of radical innovations with particular reference to propulsion systems and to aircraftarchitecture consequently. This paper presents analyses and discusses a promising propulsive architecture based on an innovative nozzle, which allows realizing the selective adhesion of two impinging streams to two facing jets to two facing Coanda surfaces. This propulsion system is known with the acronym ACHEON (Aerial Coanda High Efficiency Orienting Nozzle). This paper investigates how the application of an all-electric ACHEONs propulsion system to a very traditional commuter aircraft can improve its relevant performances. This paper considers the constraints imposed by current state-of-the-art electric motors, drives, storage and conversion systems in terms of both power/energy density and performance and considers two different aircraft configurations: one using battery only and one adopting a more sophisticated hybrid cogeneration. The necessity of producing a very solid analysis has forced to limit the deflection of the jet in a very conservative range (±15°) with respect to the horizontal. This range can be surely produced also by not optimal configurations and allow minimizing the use of DBD. From the study of general flight dynamics equations of the aircraft in two-dimensional form it has been possible to determine with a high level of accuracy the advantages that ACHEON brings in terms of reduced stall speed and of reduced take-off and landing distances. Additionally, it includes an effective energy analysis focusing on the efficiency and environmental advantages of the electric ACHEON based propulsion by assuming the today industrial grade high capacity batteries with a power density of 207 Wh/kg. It has been clearly demonstrated that a short flight could be possible adopting battery energy storage, and longer duration could be possible by adopting a more sophisticated cogeneration system, which is based on cogeneration from a well-known turboprop, which is mostly used in helicopter propulsion. This electric generation system can be empowered by recovering the heat and using it to increase the temperature of the jet. It is possible to transfer this considerable amount of heat to the jet by convection and direct fluid mixing. In this way, it is possible to increase the energy of the jets of an amount that allows more than recover the pressure losses in the straitening section. In this case, it is then possible to demonstrate an adequate autonomy of flight and operative range of the aircraft. The proposed architecture, which is within the limits of the most conservative results obtained, demonstrates significant additional benefits for aircraft manoeuvrability. In conclusion, this paper has presented the implantation of ACHEON on well-known traditional aircraft, verifying the suitability and effectiveness of the proposed system both in terms of endurance with a cogeneration architecture and in terms of manoeuvrability. It has demonstrated the potential of the system in terms of both takeoff and landing space requirements. This innovation opens interesting perspectives for the future implementation of this new vector and thrust propulsion system, especially in the area of greening the aeronautic sector. It has also demonstrated that ACHEON has the potential of renovating completely a classic old aircraft configuration such as the one of Cessna 402.

Shifting cargo from roads to eco-friendly inland waterway transport (IWT) is an important step towards reaching the decarbonization goals defined by the European Green Deal. The rehabilitation of nautical bottlenecks is essential to reach the fairway depth which is needed to allow a competitive transport on inland waterways. The goal of this paper is to (1) identify key performance indicators (KPI) associated with nautical bottlenecks caused by insufficient maintenance, (2) understand the effects of resolving nautical bottlenecks on the identified KPIs and (3) develop a conceptual framework. To develop the conceptual framework, we carried out a systematic literature review. We analysed the identified literature using qualitative content analysis and thus, derived relevant KPIs and their interdependencies. Ten KPIs were identified, which could be clustered as being either IWT-related, market-related or location-related. One example for an IWT-related KPI is the vessel draft, while market-related KPIs are e.g., referring to the KPI modal share and location-related KPIs to other KPIs such as fairway depth. The conceptual framework visualizes the interdependencies between the KPIs and facilitates further research in this field, i.e., the development of a method for the evaluation of economic benefits of resolving nautical bottlenecks on inland waterways. A scientific method that allows the economic evaluation of resolving nautical bottlenecks it is essential to demonstrates the gain in quantitative net benefit if water levels are sufficient. A quantification of the net benefit serves as a motivator to intensify maintenance work on nautical bottlenecks and to facilitate decision-making regarding infrastructure projects.

Mobility-as-a-Service (MaaS) system is regarded as one of the emerging solutions to offer integrated, seamless, and flexible multi-modal mobility services as an alternative to privately owned mobility resources. MaaS is expected to change the way users will choose their modes of transport to reach their daily activities, and how service providers will generate profits, cooperate, and compete. To successfully deploy MaaS to reach the intended goals, it is critical to develop feasible and sustainable models that capture the diverse needs of customers as well as the diverse and often competing objectives of service providers. This paper aims to provide a general modelling framework and a critical and descriptive analysis of the relevant literature relating all main actors in the MaaS ecosystem, and identify and discuss all factors that are considered relevant, focusing on the actor’s decision-making processes and their correlations. This review shows the large variety and interaction of factors influencing MaaS adoption and their impact on forecasting MaaS appeal. It is also observed that current travel behaviour and multi-modal transport models are not fully capturing the diverse travel needs and choices of potential MaaS users. Recent advancements in agent-based simulation and discrete choice modelling offer potential solutions to address this gap, and future research should aim in that direction. Finally, the review analyses the interaction between MaaS actors, including customers, service providers, the government, and the MaaS Broker, highlighting the complexity of the modelling process comprising all actors of the MaaS ecosystem. Therefore, it is recommended to prioritise future research in exploring these areas.

This study analyzes the relationship that land use has with weekend travel in comparison to weekday travel. Unlike previous studies, it uses the same sample for two models that are specified to test the relationship separately for weekday and weekend travel. Structural equation modeling is employed to test the land use–travel relationship. A comparison is made using two mode-specific travel measures: trip frequency and travel time. On weekday travel, land use in Seoul tends to reduce automobile trips and to add transit and nonmotorized trips. This does not lead to a reduction in the total frequency of weekday trips. Instead, an overall reduction occurs in the frequency of weekend trips because the addition of transit and nonmotorized trips is less than the reduction of automobile trips. The application of structural equation modeling to a Seoul household travel survey confirms the opposing role of land use in travel mode choices on weekdays versus weekends.

Harmonisation of driving laws of Rwanda with the surrounding East Africa Community (EAC) countries, which mostly drive on the left-hand side of the road, would lead to improved links between these strategic trading partners. A study to assess techno-economic viability of switching drive side from the right to left was therefore undertaken during February to August, 2009. A bottom-up approach involving wide ranging public consultation at each stage was employed. Two alternative scenarios, (i) a Do Nothing (DN) option, i.e. continue to drive as it is in the right hand side and a Do Something (DS) option, which means switching driving side from right to left were developed for an evaluation period of 20 years. All of the foregoing factors (vehicle demand projection, cost of vehicle purchase and maintenance, accidents, business interests between Rwanda, EAC and Common Market of East and Southern Africa (COMESA) countries and other neighbours) have been evaluated for the next 20 years for both options, including the financial, economic and safety impacts. According to the study if decision were made to switch despite minor increase in material only damage accidents, overall economic and financial benefit would be very substantial, which is also supported by the majority of the stakeholders (54 %).

The main aim of this study is to identify factors behind Finland having a poorer road traffic accident record compared to Sweden. Another aim is to study whether there are any benefits to using real disaggregate data. We use the term safety potential to describe how much safety would improve in Finland if the rate of a selected measure in Sweden existed in Finland as well. In our analyses we use population risk to compare safety as a main measure. Comparison of the number of fatalities per population in 2009–2013 between Finland and Sweden showed that for Finland there is a safety potential of 99 yearly fatalities out of 248. The number of fatalities per vehicle kilometre in Finland is 30% higher than in Sweden and the number of motor vehicle kilometres per person 23% higher. The highest potential for fatality reduction is for cars, related mainly to head-on fatalities. Age groups 15–17 and 18–20 years were identified as having the greatest relative population risk in Finland: the safety potential among 15–17-year-olds is seven moped and motorcycle fatalities and among 18–20-year-olds 12 car fatalities annually. Finland having the Swedish fatality risk per person kilometre would prevent six bicycle and six pedestrian fatalities per year. The extensive network of middle-barrier roads introduced in Sweden would probably offer the most extensive safety benefit for Finland also. Advanced use of disaggregated data provides more options than programmes created for analysing aggregate data.

Modern urban-transport planning requires evidence-based insights into current transport flows to better understand the needs and impacts of policymaking. Urban transport includes passenger and freight vehicles, which have different behavior, and the need for such a separation is often ignored in research and practice [1]. New digital data sources provide an opportunity to better understand urban transport and identify where policy interventions are required. We review the literature on digital counting techniques to monitor transport flows, including loops, Automatic-Number Plate Recognition (ANPR) cameras and floating car data. We further investigate the potential of ANPR cameras, which are widely deployed, and which can be augmented with vehicle category information. This article presents the methodology that we follow for transforming raw augmented ANPR camera data into practical knowledge for city planners. Our is aim is to provide a better understanding of passenger and freight vehicle movements and stops, identifying similarities and differences between vehicle categories. We demonstrate our methodology on a case study for the Mechelen-Willebroek district in Belgium, encompassing augmented data from 122 ANPR cameras for a period of two weeks. Additionally, we also look at the car-reduced zone and how time restrictions affect the different vehicle categories’ actions. The findings are validated with GPS data from heavy-good vehicles in the same period. The potential of augmented ANPR camera data and promising themes and applications of this data source are illustrated through the case study.