Increase In Road Capacity Research Articles

WITHDRAWN: Evaluating Collaborative Emission Reduction Efforts in Urban Road Passenger Transportation: insights from the City Scale

Road passenger transportation contributes significantly to carbon dioxide (CO2) and pollutant emissions, posing challenges for urban sustainability, particularly in rapidly urbanizing cities such as Fuzhou, which was recognized as a global sustainable development city for 2023. This study addresses the research gap by integrating road green factors, which refer to the ecological attributes of roads, such as green space, vegetation, and tree coverage that contribute to improving air quality and reducing pollution, into emission reduction strategies for city-scale road passenger transportation. This novel approach has not been extensively explored in the existing literature. The purpose of this study was to identify a rational pathway for emissions reduction by analyzing the economic, demographic, transportation infrastructure, road green space, and policy factor impacts on emissions. Employing a system dynamics (SD) model, this research evaluates the emissions from road passenger transportation in Fuzhou from 2010 to 2030 under various scenarios, including a baseline scenario (BS), controlled private cars travel demand (CPD), promotion of new energy vehicles (PVE), improvement in energy efficiency (IEE), increase in road capacity (IRC), and improvement in road green level (IRG). The principal results indicate that by optimizing the traffic structure and integrating other emission reduction measures, peak CO2 emissions can be achieved by 2024 under the three scenarios or by 2023 under the four scenarios. Furthermore, significant reductions in pollutants of 84.62% and 86.07% are projected, respectively. The study concluded that the economic benefits of CO2 emissions reductions consistently exceeded those of carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx) reductions, highlighting the importance of a holistic approach to emissions reduction strategies. Based on these findings, policy recommendations were proposed to guide the formulation of effective road passenger transportation policies aimed at achieving sustainable urban development.

Risk-informed longitudinal control in autonomous vehicles: A safety potential field modeling approach

The advent of autonomous vehicles (AVs) has complicated traffic flow and raised safety concerns, there is a pressing need to enhance traffic efficiency alongside ensuring robust safety. This paper proposes a dynamic longitudinal control strategy for AVs, based on real-time accident risk assessments. Data from traffic flow, road characteristics, and weather conditions are analyzed using a random forest algorithm, producing a real-time accident risk identification model through a support vector machine. In addition, the Perceived Risk Field Model (PRFM), a car-following model calibrated using the NGSIM dataset, considers vehicle distance, velocity, relative velocity, and acceleration. These models underpin our proposed longitudinal control strategies, tailored to variable accident risk levels. Under the normal risk control strategy, the PRFM outperforms the Intelligent Driver Model (IDM) and the Cooperative Adaptive Cruise Control Model (CACC) in stability and driving comfort. For high accident risk scenarios, our approach shows improved collision avoidance and traffic oscillation mitigation. Simulations indicate that the high accident risk control strategy offers better safety and stability than the normal risk strategy. Furthermore, traffic flow diagrams suggest an increase in road capacity as AV penetration rates rise, pointing to the promising efficiency of our proposed solution. This research provides a robust framework for AV operation, ensuring optimal traffic safety and efficiency.

Centralized Model Predictive Control With Human-Driver Interaction for Platooning

Cooperative adaptive cruise control presents an opportunity to improve road transportation through increase in road capacity and reduction in energy use and accidents. Clever design of control algorithms and communication systems is required to ensure that the vehicle platoon is stable and meets desired safety requirements. In this paper, we propose a centralized model predictive controller for a heterogeneous platoon of vehicles to reach a desired platoon velocity and individual inter-vehicle distances with driver-selected headway time. As a novel concept, we allow for interruption from a human driver in the platoon that temporarily takes control of their vehicle with the assumption that the driver will, at minimum, obey legal velocity limits and the physical performance constraints of their vehicle. The finite horizon cost function of our proposed platoon controller is inspired from the infinite horizon design. To the best of our knowledge, this is the first platoon controller that integrates human-driven vehicles. We illustrate the performance of our proposed design with a numerical study, demonstrating that the safety distance, velocity, and actuation constraints are obeyed. Additionally, in simulation we illustrate a key property of string stability where the impact of a disturbance is reduced through the platoon.

Operation analysis of freeway mixed traffic flow based on catch-up coordination platoon

As one of the innovative technologies of intelligent transportation systems (ITS), Connected and Autonomous Vehicles (CAVs) have been deployed gradually. Given that there will be a long transition period before reaching a fully CAVs environment, it is crucial to assess the potential impacts of CAVs on mixed traffic flow. Considering platoon formation process, this study develops a platoon cooperation strategy based on “catch-up” mechanism, and then analyzes the impact on fundamental diagram, traffic oscillation, and traffic safety within mixed traffic. Simulation results show that with an increasing market penetration rate (MPR) of CAVs, road capacity shows an increasing trend. Compared with base scenario, a clear increase in road capacity is also observed under platoon scenario. With an increasing MPR, traffic oscillation is shown to reduce largely. Furthermore, the proposed platoon strategy could dampen frequent shockwaves and shorten the propagation range of waves. Regarding traffic safety, multiple surrogate safety measures (SSMs) are used to evaluate the traffic risk: including Criticality Index Function (CIF), Potential Index for Collision with Urgent Deceleration (PICUD), and Deceleration Rate to Avoid a Crash (DRAC). With increasing MPR, collision risk identified by CIF and DRAC shows an increase tendency, while that identified by PICUD has no apparent trend. Furthermore, the platoon strategy is shown to increase the severity of traffic conflicts significantly. Overall, this study provides novel insights into CAVs deployment through the analysis of platoon strategy.

An Intelligent Traffic Surveillance System Using Integrated Wireless Sensor Network and Improved Phase Timing Optimization.

The transportation industry is crucial to the realization of a smart city. However, the current growth in vehicle numbers is not being matched by an increase in road capacity. Congestion may boost the number of accidents, harm economic growth, and result in higher gas emissions. Currently, traffic congestion is seen as a severe threat to urban life. Suffering as a result of increased car traffic, insufficient infrastructure, and inefficient traffic management has exceeded the tolerance limit. Since route decisions are typically made in a short amount of time, the visualization of the data must be presented in a highly conceivable way. Also, the data generated by the transportation system face difficulties in processing and sometimes lack effective usage in certain fields. Hence, to overcome the challenges in computer vision, a novel computer vision-based traffic management system is proposed by integrating a wireless sensor network (WSN) and visual analytics framework. This research aimed to analyze average message delivery, average latency, average access, average energy consumption, and network performance. Wireless sensors are used in the study to collect road metrics, quantify them, and then rank them for entry. For optimization of the traffic data, improved phase timing optimization (IPTO) was used. The whole experimentation was carried out in a virtual environment. It was observed from the experimental results that the proposed approach outperformed other existing approaches.

Distributed Urban Platooning towards High Flexibility, Adaptability, and Stability

Vehicle platooning reduces the safety distance between vehicles and the travel time of vehicles so that it leads to an increase in road capacity and to saving fuel consumption. In Europe, many projects for vehicle platooning are being actively developed, but mostly focus on truck platooning on the highway with a simpler topology than that of the urban road. When an existing vehicle platoon is applied to urban roads, many challenges are more complicated to address than highways. They include complex topology, various routes, traffic signals, intersections, frequent lane change, and communication interference depending on a higher vehicle density. To address these challenges, we propose a distributed urban platooning protocol (DUPP) that enables high mobility and maximizes flexibility for driving vehicles to conduct urban platooning in a decentralized manner. DUPP has simple procedures to perform platooning maneuvers and does not require explicit conforming for the completion of platooning maneuvers. Since DUPP mainly operates on a service channel, it does not cause negative side effects on the exchange of basic safety messages on a control channel. Moreover, DUPP does not generate any data propagation delay due to contention-based channel access since it guarantees sequential data transmission opportunities for urban platooning vehicles. Finally, to address a problem of the broadcast storm while vehicles notify detected road events, DUPP performs forwarder selection using an analytic hierarchy process. The performance of the proposed DUPP is compared with that of ENSEMBLE which is the latest European platooning project in terms of the travel time of vehicles, the lifetime of an urban platoon, the success ratio of a designed maneuver, the external cost and the periodicity of the urban platooning-related transmissions, the adaptability of an urban platoon, and the forwarder selection ratio for each vehicle. The results of the performance evaluation demonstrate that the proposed DUPP is well suited to dynamic urban environments by maintaining a vehicle platoon as stable as possible after DUPP flexibly and quickly forms a vehicle platoon without the support of a centralized node.

Wybrane zagadnienia projektowania infrastruktury przeznaczonej do ruchu rowerów w perspektywie bezpieczeństwa ruchu drogowego

Increasing mobility results in growing overcrowding of roads and streets. Attempts to improve travel conditions through an increase in road capacity usually only worsen the situation. The main purpose should be an increased share of public transport, including bicycle traffic, in the modal split. An increased share of bicycles in everyday traveling requires, however, a competitive advantage of that means of transport over other transport possibilities. It involves the need for adequate infrastructure which would provide bicycle users with the possibility to move efficiently, comfortably, and above all, safely. This paper describes the problems resulting from insufficient quality of the regulations on cycling infrastructure design and proposes directions of changes and complements that are vital for traffic safety. It applies mainly to design speed on bicycle routes, widening of bikeways on curves, bikeway clearances, and visibility on cycle crossings enabling uninterrupted cycling.

Adaptive Traffic Light Controller Based on Congestion Detection Using Computer Vision

The transportation sector plays an important role in realizing a smart city. The increase in the number of vehicles is currently not supported by an increase in road capacity. Traffic jams or congestion will occur in many places. Congestion will increase the accident rate, bad effect on economic growth, and increase gas emissions. Effective traffic management is necessary to reduce congestion levels and its side effects. A traffic light is one of traffic management methods. Traffic lights control the flow of traffic at road intersections, zebra crossings, and other traffic flow points. Conventional traffic lights work on a pre-programmed time sequence. This system is effective if the vehicle density is relatively constant. The density of vehicles from various directions fluctuates with time. To increase the effectiveness of using traffic light, an adaptive system is needed. In this study, a simple adaptive traffic light mechanism was developed based on congestion on the road using computer vision. Vehicle congestion is detected using the YOLOv3 object detection which detects the type of vehicle. The detection system used by YOLOv3 with pretrained weight COCO has a true positive value for motorbikes of 60%, cars (light vehicles) 93%, and trucks/buses (heavy vehicles) 100%. The processing speed of the Jetson Nano mini-PC with the OpenCV library on the GPU is 2 times faster than the process with the CPU.

Operational Plan For The Numbers Using Fast Mass Transport Trem In Surabaya

Traffic jams often occur in the city of Surabaya. Due to the increasing population and the desire to have private vehicles, this has led to the need for adequate additional road capacity. However, the frequent increase in road capacity is not enough with the very high growth of road users. Therefore, the Surabaya city government planned an alternative route to reduce the congestion that occurred, one of which was building a rapid mass transportation, the tram, the construction of the tram itself was still in the planning stage, requiring a study of the influence of operational plans on public interest in trams, specifically for motorcyclists. What factors can make motorbike riders divert to the tram. One way to find out how much interest motorbike riders have is to use multiple linear regression methods which require data from road users. Questionnaires are needed to retrieve data and collect samples consisting of 200 respondents. In this study the location of the deployment is in the area that trams are going to plan for, starting from Joyoboo - Jl.Raya Darmo - Urip Sumoharjo - Jl.Basuki Rahmat - Jl.Embong Malang - Jl.Blauran - Jl.Bubutan - Tugu Pahlawan - Jl. Indrapura - Jl. Rajawali. While going south will pass Jl. Heroes - Jl. Gemblongan - Jl, Tunjungan - Jl. Governor Suryo - Jl. Panglima Sudirman - Jl. Urip Sumoharjo - Jl. Raya Darmo - Terminal Joyoboyo

Right-of-way reallocation for mixed flow of autonomous vehicles and human driven vehicles

Autonomous Vehicles (AVs) are bringing challenges and opportunities to urban traffic systems. One of the crucial challenges for traffic managers and local authorities is to understand the nonlinear change in road capacity with increasing AV penetration rate, and to efficiently reallocate the Right-of-Way (RoW) for the mixed flow of AVs and Human Driven Vehicles (HDVs). Most of the existing research suggests that road capacity will significantly increase at high AV penetration rates or an all-AV scenario, when AVs are able to drive with smaller headways to the leading vehicle. However, this increase in road capacity might not be significant at a lower AV penetration rate due to the heterogeneity between AVs and HDVs. In order to investigate the impacts of mixed flow conditions (AVs and HDVs), this paper firstly proposes a theoretical model to demonstrate that road capacity can be increased with proper RoW reallocation. Secondly, four different RoW reallocation strategies are compared using a SUMO simulation to cross-validate the results in a numerical analysis. A range of scenarios with different AV penetration rates and traffic demands are used. The results show that road capacity on a two-lane road can be significantly improved with appropriate RoW reallocation strategies at low or medium AV penetration rates, compared with the do-nothing RoW strategy.

Modelling Reliability of Transportation Systems to Reduce Traffic Congestion

Reliability reflects the level of ease of people and goods to travel. Reliability relates with the variability of travel time, speed, and system usage and transportation system capacity. The higher the capacity of the system and the faster the travel time, the higher the level of reliability of the transportation system, so that it can reduce traffic congestion. Traffic congestion will occur when travel requests exceed road capacity. Our research attempts to provides a comprehensive and objective assessment of improving reliability of transportation systems and its impact to reduce traffic congestion. We utilized system dynamics simulation model to test and evaluate the alternatives of future strategies to increase the reliability of transportation systems and its impact to reduce traffic congestion. Systems dynamics models can be developed at the macroscopic and microscopic levels of transportation systems as well as to evaluate the effects of different transportation policies on traffic congestion. Simulation results show that reliability is determined by several factors such as travel time, headway (the time between two means of transportation to pass a point / place), passenger wait time; access time and egress time (the time needed to get off the vehicle when it arrives at the destination). Transportation systems reliability continues to decline so that in 2017, reliability was only around 41.5%. The improvement scenario of transportation system reliability can be done by conducting several strategies such as increasing road capacity, increasing public vehicle routes around public facilities, as well as increasing the supply of public transportation which has an impact on headway and waiting time. By conducting these strategies, the reliability of transportation systems could be increased to be around 53.3% and a gradual increase in road capacity could be done with a growth of 2.8% per year. Within this condition, the traffic congestion is projected to be around 74.9% - 83.6% in the period 2019-2027, and then to be around 83-88% in the period 2028-2035.

The challenge of sustainable mobility in urban planning and development: a comparative study of the Copenhagen and Hangzhou metropolitan areas

The theme of this article is how the challenge of sustainable mobility has been dealt with in urban planning and urban development in the metropolitan areas of Copenhagen (Denmark) and Hangzhou (China). The two metropolises have followed different trajectories in their land use and transport infrastructure development since the 1990s. Land use policies in Copenhagen have to some extent been explicitly geared towards limiting traffic growth, to a less extent in Hangzhou. In both cities, public transport improvements have been combined with road capacity increases. The trajectories of the two city regions reflect the dominating ideas among planners and public decision-makers, as well as a number of different economic, political, social, topographical and cultural conditions.

On their road to sustainability?: The challenge of sustainable mobility in urban planning and development in two Scandinavian capital regions

The metropolitan areas of Copenhagen (Denmark) and Oslo (Norway) both aim to facilitate economic development, opportunities for choice and growth in the building stock while limiting negative environmental consequences. Since the 1990s, the rate of consumption of land for urban development has been lower than the economic growth rate in both city regions. Land use policies in Oslo and to some extent in Copenhagen have been explicitly geared towards limiting traffic growth. In both cities, public transport improvements have been combined with road capacity increases. Traffic growth has therefore only been weakly decoupled from economic growth. In both city regions, lack of coordination between sectors, levels and administrative territories is conceived a barrier to sustainability.

Oslo's Farewell to Urban Sprawl

Sustainable mobility has been an important concern in urban planning and development in Oslo Metropolitan Area since the 1990s. The period has been characterized by concentrated and compact urban development, especially within the municipality of Oslo. This has contributed to a reduction in growth in car traffic. Analyses of selected land use and transport plans and policy documents, professional journal articles and interviews with key actors show that there has been a high degree of consensus about this spatial development strategy. Considerable investments have been made in public transport as well as in road development; the former based on broad consensus. Road capacity increases have been contested among professionals but widely supported by politicians.

The eco-city: ten key transport and planning dimensions for sustainable city development

Making existing cities and new urban development more ecologically based and liveable is an urgent priority in the global push for sustainability. This paper discusses ten critical responses to this issue and summarizes them in a simple conceptual model that places the nexus between transport and urban form at the heart of developing an eco-city. This involves compact, mixed-use urban form, well-defined higher-density, human-oriented centres, priority to the development of superior public transport systems and conditions for non-motorized modes, with minimal road capacity increases, and protection of the city's natural areas and food-producing capacity. These factors form the framework in which everything else is embedded and must operate, and if they are not addressed only marginal changes in urban sustainability can be made. Within this framework, environmental technologies need to be extensively applied. Economic growth needs to emphasize creativity and innovation and to strengthen the environmental, social and cultural amenities of the city. The public realm throughout the city needs to be of a high quality, and sustainable urban design principles need to be applied in all urban development. All these dimensions need to operate within two key processes involving vision-oriented and reformist thinking and a strong, community-oriented, democratic sustainability framework for decision-making.

The specification of sustainable urban transport strategies

Transport strategies have been developed for nine European cities to achieve optimum performance in terms of a range of objective functions. The functions selected represent economic efficiency, sustainability and a combination of these. The strategies have been based on combinations of a standard set of policy instruments, including public transport infrastructure, frequency and fares, road capacity increases, low cost road pricing and parking charges. The optimisation method is described, and results presented. The reactions of city authorities to the proposed strategies are discussed and implications for transport policy outlined.

Behavioral Aspects of Automatic Vehicle Guidance: Relationship Between Headway and Driver Comfort

Automation of road traffic has the potential to greatly improve the performance of traffic systems. The acceptance of automated driving may play an important role in the feasibility of automated vehicle guidance (AVG), comparable to automated highway systems (AHS). Because decreasing headways could mean a large increase in road capacity, a study was conducted concerning the acceptability of short headways in an automated traffic system. In one part of a driving simulation experiment, subjects gave ratings on comfort regarding the headway in an automated lane; in another part of the experiment, subjects were allowed to adjust the headway setpoint to a comfortable level. Subjects also rated the comfort level when driving under manual control in a number of traffic conditions. Results showed that to equal the comfort level that people experience daily in dense traffic on the freeway network in rush hours, the AVG headway should be no less than 0.86 sec. If a comfort level that people experience daily during incident situations (not uncommon in unstable traffic flow) would be acceptable, the AVG headway could be as short as 0.29 sec. The AVG headways as set by the subjects correspond to the values observed in normal traffic (on average 1.1 sec).