Urban Road Capacity Research Articles

Influence of pedestrian movement on speed of vehicles, capacity and level of service of urban midblock sections

Side friction factors are all those actions related to the activities taking place by the sides of the road and sometimes within the road, which interfere with the traffic flow on the travelled way. They include but not limited to pedestrians, bicycles, non-motorized vehicles, parked and stopping vehicles. These factors are normally very frequent in densely populated areas in developing countries, while they are random and sparse in developed countries making it of less interest for research and consequently there is comparatively little literature about them. The objective of this thesis is to analyze the effect of these factors on capacity of urban roads. The present study is mainly focused on individual effect of the friction factors like pedestrians crossing the road on capacity of urban roads. Data on two sections of 4-lane divided road were collected in Hyderabad with pedestrian cross flow. These are taken as the base sections. Three basic parameters of traffic speed, volume and density are used for estimation of traffic carrying capacity of a road. For determination of speed-volume relationship in heterogeneous traffic condition, the volume calculated by total vehicles recorded for each counting period were converted into equivalent number of PCUs. Mean stream speed or weighted space mean speed is calculated and used in the present study. The present study demonstrates that mix traffic stream can be converted in to an homogeneous equivalent of passenger cars by multiplying the total traffic volume (in veh/hr) by a stream equivalency factor (K). It will avoid the problem of estimation of PCU values for individual vehicle categories in the traffic stream. The stream equivalency factor (K) will depend on traffic composition and a regression equation is developed in this study to estimate K-value on urban roads.

Arrangement of Access to the Religious Tourism Area of The Tomb K.H. Abdurrahman Wahid Jombang Regency

Jombang Regency is one of the regencies in the East Java region that boasts numerous tourist destinations. One of the religious attractions in Jombang Regency is the Tomb of K.H. Abdurrahman Wahid. Suboptimal road traffic conditions occur in the tourism area, particularly on K.H. Hasyim Asyari Street. This road segment frequently experiences high traffic volume due to tourism activities, numerous obstacles such as roadside parking, and non-motorized vehicles moving around the tourism area. This research adheres to the Guidelines for Indonesian Road Capacity (PKJI) 2014 regarding Urban Road Capacity. The primary data required for this study include geometric road data, traffic volume data, and roadside obstacle data. Meanwhile, secondary data in this study comprise road network data and Average Daily Traffic (ADT) data from the relevant authorities, namely the Jombang Regency Transportation Agency. From the traffic performance calculations, the saturation degree values for the existing conditions on K.H. Hasyim Asyari Street towards the south (DJ) = 0.7624 and towards the north (DJ) = 0.7075 were obtained. Based on the survey results, K.H. Hasyim Asyari Street towards the north has a capacity (C) = 2465, and towards the south, it also has a capacity (C) = 2465. The parking space requirements in the Religious Tourism Area of the Tomb of K.H. Abdurrahman Wahid (Gus Dur) are planned to be 171 parking spaces for motorcycles, 54 parking spaces for cars, and 53 parking spaces for buses.

Study of medium and long-term free flow capacity and queue discharge rates on roads.

With the rise in vehicle ownership, traffic congestion has emerged as a major barrier to urban progress, making the study and optimization of urban road capacity exceedingly crucial. The research on the medium and long-term free-flowing capacity and queue emission rate of roads takes an in-depth exploration of this issue from a cutting-edge perspective, aiming to find solutions adaptable to the progression of the times. The purpose of this study is to understand and predict the road capacity and queue emission rate more accurately, thus improving the urban traffic condition. Existing literature primarily focuses on short-term forecasts of road capacity, leaving a notable void in the research of medium and long-term road capacity and queue emission rate. This gap often results in a lack of sufficient foresight when urban traffic planning faces practical issues. To fill this void, this study undertook an in-depth examination of the road capacity and queue emission rate over the medium and long term (10 years) based on big data analysis and artificial intelligence theories. This paper employs a Radial Basis Function (RBF) neural network, combined with twelve other parameters that could potentially impact road capacity, such as traffic volume, road width, number of lanes, traffic signal control methods, etc., to analyze the relationship between each parameter and free-flow traffic and queue emission rate. These analyses are grounded in extensive road data, encompassing not only the city's main roads but also secondary roads and community roads. The study results show a continuous downward trend in the free-flowing capacity of roads and a slight upward trend in the queue emission rate over the past decade. Further analysis reveals the extent of impact each factor has on the free-flow traffic and queue emission rate, providing a scientific basis for future urban traffic planning.

Discussion on Construction Technology of Road Subgrade in Civil Engineering

With the rapid development of cities, more and more new roads are built in various civil engineering projects. Subgrade construction is the core of road engineering system. Only by comprehensively ensuring the quality of road subgrade can the road performance be effectively improve and the development of urban construction be ensured. The quality of subgrade determines the traffic capacity of urban roads and plays a decisive role in the safety and stability of traffic. This article mainly analyzes the problems of road subgrade construction in civil engineering, and comprehensively puts forward countermeasures, so as to effectively improve the subgrade construction quality and ensure the smooth operation of roads.

Supply-demand relationship and spatial flow of urban cultural ecosystem services: The case of Shenzhen, China

Cultural ecosystem services (CES) have garnered significant attention due to their capacity to comprehensively evaluate the influence of ecosystem degradation on human well-being. It is very important to evaluate the spatial coordination relationship between the supply and demand of urban CES and explore its spatial flow mechanism for guiding the sustainable development of urban regions. However, research on the relationship between supply and demand of urban CES and their spatial flows is still in the conceptual exploration stage, and its quantitative assessment methods are not yet mature. Taking Shenzhen as an example, this study uses the Social Values for Ecosystem Services model to evaluate the supply of CES based on environmental background and survey statistics; Uses the topic model of natural language processing, quantify the demand of CES based on social media data. The Bivariate Local Indicators of Spatial Association index is utilized to examine the correlation between supply and demand, while a crowd activity extraction method based on mobile phone signaling data is developed to simulate the spatial flow pattern of CES. The results show that: (1) The supply of urban CES shows obvious spatial differentiation; There are differences in the perception of the needs of various CES. Among them, the beneficiaries have higher needs for Aesthetic and Recreation. (2) The relationship between supply and demand of urban CES shows different degrees of spatial mismatch, with the proportion of the supply-demand matching area to the total area being less than 20%, and the main type of supply-demand mismatch being low supply-high demand. (3) All kinds of CES flow from the center of the study area to the east, among which the flow of recreation and Aesthetic is more active, with the highest flow of 189.7 and 135.3, respectively. Overall, the coordination between various types of CES in the region is still insufficient. We should encourage the establishment and improvement of a diversified transportation system connecting the central urban area and other regions while enhancing the condition of the local ecological conditions, to improve the capacity of urban ring roads and rail transit, to promote the sustainable development of the regional ecological environment and social economy, and to enhance human well-being.

Road construction and air pollution: Analysis of road area ratio in China

Faced with complex air pollution and traffic congestion, the road area ratio has gradually gained great importance in society and government. It is the ratio introduced from the field of road design and road engineering, but to study the efficiency of city planning and transportation recently. However, few studies have been conducted to study the relationship between urban congestion and pollution in the view of improving road area ratio. This paper investigated the effect of increasing the relative capacity of urban roads, i.e., road area ratio, on urban air pollution using panel data from cities in China from 2006 to 2018. In addition, the road area ratio can be further decomposed to explore the inner logic of pollution from congestion. Thus, we also explored whether the insufficient network density or width caused the pollution from congestion. We found that an increasing urban road area ratio significantly reduced air pollution, regardless of whether or not the impact of surrounding cities is included. Moreover, only an increased road density can increase traffic efficiency and reduce congestion emissions, which should be the priority of future traffic construction. The effect of increasing road width is not significant.

The Impact of Road Side Friction on the Traffic Flow of Arterial Roads in Varanasi

Varanasi's prominence as a cultural and historical center means it receives visitors from all over the world. The city's tourism industry is a boon to the local economy. Better transportation infrastructure is crucial to attracting more tourists and increasing revenue. Varanasi is currently experiencing terrible difficulties due to various roadside frictional activities. Vehicle ownership grows in tandem with population growth. The increase in the number of vehicles on the road significantly impacts the reliability of the transportation network since land availability is fixed. The various roadside frictional activities usually found in the streets of Varanasi are on-street parking, pedestrian crossing, and Non-Motorized Vehicles (NMVs). There are not enough legal on-street parking and segregated lanes for NMVs/slow-moving vehicles or demarcation for pedestrian movements in the old city of Varanasi. Vehicles in Varanasi are traditionally parked on the street due to the narrow carriageways. Slow-moving vehicles are forced to move with fast-moving vehicles, and pedestrian crossings affect traffic flow. Integrated movement of slow-moving vehicles and rapid-moving vehicles affects traffic speed, pedestrian crossings impact the Level of Service (LOS), and on-street parking results in the reduction of the effective carriageway width and, hence, road capacity. This paper aims to identify the impact of pedestrian crossings, NMVs, and on-street parking on the traffic flow, speed, capacity, and LOS of urban arterial roads in Varanasi. To achieve this objective, two case studies were considered: the base section (with minimum side friction) and the friction section (with maximum side friction). The videography method was used for data collection. Nine hours of data were collected from 9:30 am to 6:30 pm. The video was played on the screen for data extraction. The speed model was developed by using fundamental diagram methods. Speed-density curve was drawn using Greenshield’s model. The speed-flow curve was derived from the speed-density curve to estimate the capacity at the base and friction sections. Reduction in capacity was determined by comparing friction section capacity with base section capacity. V/C ratio of a particular road compared with the V/C value provided by IRC 106 to predict LOS. A correlation model was developed between the percentage reduction in capacity and road width. Increase in parking, the proportion of NMVs, and pedestrian crossing frequency reduce the traffic flow. It was observed that a 6.42% capacity loss occurs at a 7.00% reduction in effective width, and a 35.09% loss occurs at a 36.02% reduction in effective width. Roads with frictional activities found their LOS class affected up to LOS-E (for the Bhelupur section).

Research on the impact of underground excavation metro on surface traffic safety and assessment method

ABSTRACT This study focuses on a problem that has been seriously troubled urban traffic managers: the impact of underground excavation metros on surface traffic safety during construction. In underground construction, surface subsidence and road collapse due to concealed underground construction constantly occur, resulting in casualties property damage and seriously impairing normal urban road traffic. Urban road managers urgently need a quick, objective, and easy-to-use method for the early warning and prevention of such risks. Therefore, this study collates relevant accident cases that have occurred in China over the last 20 years and summarises the impact mechanisms of concealed underground works affecting surface road traffic capacity through a detailed study of natural factors, engineering geology, types of structures, and types of workmanship. Two indices, Rank() and , are proposed to describe the impact of concealed underground works on surface traffic capacity, while an early warning method based on data on the impact of urban road capacity by concealed underground works is established using integrated learning methods and is well applied in practical projects. The results of this study are important for helping city managers quickly assess urban road traffic risks.

Operational Assessment of Speed Control Measures on Capacity of Urban Roads in Metropolitan Area of Barranquilla, Colombia

With the aim to reduce accident rates and assist in pedestrian traffic, in the city of Barranquilla (Colombia), electronic devices for speed control (speed cameras) have been installed on roads of high vehicular flow with difficulty in pedestrian transit. Traffic Calming Measures are described in the literature as a set of measures to regulate traffic on roads, ensure mobility, and reduce accidents. This article focuses its study on the impact of Traffic Calming Measures through electronic devices on urban or inner cities roads (capacity and operating speed on them). This study centers in the evaluation of the operational impact of speed cameras and the data of vehicular speed and flow collected through them in four main roads of the city, with the purpose of estimating models that establish relationships of speed-flow, and analyzing the impact of these Traffic Calming Measures on the vehicular capacity of urban roads. In the estimation of road capacity, a Greenshields model was applied, with which via speed–density and flow-density relationships, we aim to determine how operational transit is affected by the use of speed cameras. Conclusions show that operational transit is affected by diminishing road capacity between 7 to 41 percent and these Traffic Calming measures are ineffective to ease pedestrian traffic as is expected.

A Lane-Changing Decision-Making Model of Bus Entering considering Bus Priority Based on GRU Neural Network.

A mandatory lane change occurs when buses are ready to enter the station, which will easily cause a reduction of urban road capacity and induce traffic congestion. Using deep learning methods to make lane-changing decisions has become one of the research hotspots in the field of public transportation, especially with the development of the Cooperative Vehicle-Infrastructure System. Aiming at the exploration of the bus lane-changing rules and decisions during entering, we built a GRU neural network model considering bus priority by using the first real-world V2X (vehicle to everything) dataset. Firstly, we illustrated the image and point cloud data processing by coordinate transformation. Secondly, the Kalman filtering algorithm was used to evaluate the vehicle state. Combined with the bus priority rules, we propose a flexible right-of-way lane in front of the bus stop. And then, we obtain the feature variables as inputs to the model. The XGBoost algorithm was chosen to train the GRU model. Results show that the model has higher identification accuracy for lane-changing maneuvers by comparison with other models. It plays a very important role in providing a decision basis for more refined bus operation management.

Investigating Accessibility of Hospitals in Cold Regions: A Case Study of Harbin in China.

The objective of this study is to explore healthcare resource accessibility in Harbin, a typical city in a cold region in China. Recently, investments in the construction of medical resources have been increasing annually in China, and consequently, the allocation of these resources has improved. Snow and ice on surfaces in China's cold regions have certain effects on the traffic capacity of urban roads, leading to a great difference in the accessibility of medical resources in winter and summer. The basic spatial data, including spatial road data, medical facility data, and population distribution data, are analyzed using geographic information system. Then, a spatial barrier model is used to measure healthcare accessibility based on geographic and population weighting; we explore the accessibility of hospitals under the influence of weather by defining a novel distance attenuation function. Finally, the accessibility of medical institutions in the study area is explored by analyzing data about the related separation factors. It was found that the spatial distribution of medical resources was not equal, and the dominant resources were concentrated in the city center. Some regions are always in an advantageous position regardless of traffic conditions. In contrast, in areas far from the city center, the accessibility of medical resources significantly decreases in winter. These results will help optimize the layout of medical institutions and improve medical equality and propose strategies for the optimization of the accessibility of urban medical institutions in cold regions of China.

Deconstruction of the Optimal Design of Urban Road Interchange Based on the Integration of Smart Transportation and Big Data.

Urban interchange is the core hub connecting various regions, and it is of great significance for alleviating the problem of traffic congestion. In the process of urban interchange design, it is impossible to strictly control the traffic volume, interchange types, and standards by relying on traditional technologies. Smart transportation and big data are emerging technologies based on data, which can provide technical support for design and decision making. Based on this, this paper first uses smart transportation and big data technology to predict the traffic volume of Nancheng New District, so as to calculate the future development trend of the target area. Then, on the basis of traffic volume, the article uses smart transportation and big data technology to optimize the original urban interchange design scheme from the aspects of traffic capacity, safety, economic benefits, and environmental benefits. Finally, the article evaluates the optimized urban interchange scheme by means of comprehensive quantitative indicators and evaluation methods. Experiments show that the traffic capacity of the interchange on the outer ring road optimized by smart transportation and big data has increased to 72.6%, and the environmental coordination has increased from 45.2% to 55.2%. Moreover, the design aesthetics of the urban interchange after optimized design based on smart transportation and big data has increased to 65.9%. In addition, the comprehensive evaluation value of the urban interchange after optimization of smart transportation and big data reached 82.6. This fully shows that the optimal design of urban interchange based on the integration of smart transportation and big data can greatly improve the traffic capacity of urban roads.

Urban main road capacity reduction: Adaptations, effects and consequences

Abstract To support sustainable urban mobility strategies, reallocating road space from private vehicles to other uses may be a relevant intervention. Novel empirical knowledge could reduce barriers for implementing such interventions. A planned, 14-month capacity reduction of a main road tunnel in Oslo, Norway, carrying 70,000 vehicles a day, offered an excellent opportunity to document how commuters adapted, and what effects and consequences they experienced. Analyses of traffic data were combined with surveys and interviews with commuters. Congestion increased in the tunnel and on adjacent road-links, although road users adapted in ways resulting in significant traffic reduction through the tunnel. Some employees in an area near the tunnel experienced increased time-usage on their commute, and some adapted by changing transport mode, route, or trip-timing. However, results showed that they did not experience major negative consequences. Few commuters reported a need to shift routines in the household, and commuter satisfaction remained high.

Building the Traffic Flow Network with Taxi GPS Trajectories and Its Application to Identify Urban Congestion Areas for Traffic Planning

Traffic congestion is becoming a critical problem in urban traffic planning. Intelligent transportation systems can help expand the capacity of urban roads to alleviate traffic congestion. As a key concept in intelligent transportation systems, urban traffic networks, especially dynamic traffic networks, can serve as potential solutions for traffic congestion, based on the complex network theory. In this paper, we build a traffic flow network model to investigate traffic congestion problems through taxi GPS trajectories. Moreover, to verify the effectiveness of the traffic flow network, an actual case of identifying the congestion areas is considered. The results indicate that the traffic flow network is reliable. Finally, several key problems related to traffic flow networks are discussed. The proposed traffic flow network can provide a methodological reference for traffic planning, especially to solve traffic congestion problems.

Discussion on Construction Technology of Road Subgrade in Civil Engineering

With the rapid development of cities, more and more new roads are built in various civil engineering projects. Subgrade construction is the core of road engineering system. Only by comprehensively ensuring the quality of road subgrade can the road performance be effectively improve and the development of urban construction be ensured. The quality of subgrade determines the traffic capacity of urban roads and plays a decisive role in the safety and stability of traffic. This article mainly analyzes the problems of road subgrade construction in civil engineering, and comprehensively puts forward countermeasures, so as to effectively improve the subgrade construction quality and ensure the smooth operation of roads.

Optimal signal timing design for the intersection of Dazhi Street and Hexing Road

The phenomenon of intersection congestion has become a major problem in the city. Based on the intersection of Hexing road and Dazhi street, the delay phenomenon of Urban Road intersection is optimized. The intersection of Hexing road and Dazhi street is seriously delayed. In order to improve the road capacity of the intersection and reduce the delay of the intersection, the traffic characteristics parameters of the intersection during peak period are obtained, and the traffic capacity and intersection service level of the signalized intersection are analyzed and calculated. Based on the study of the basic content and research methods of signal timing at signalized intersections, the microscopic simulation software VISSIM was used to improve the traffic control scheme with serious delays at intersections and low urban road capacity, the simulation optimization is carried out by changing the signal timing and resetting the channelization scheme of intersection. Meanwhile, the signal timing of intersection is optimized. The results show that the traffic capacity of the intersection has been greatly improved by VISSIM simulation.

Analisa Faktor Penyebab Kemacetan Lalu Lintas di Jalan Kolektor Studi Kasus Jalan Gajah Mada Gunung Pangilun Kota Padang

Congestion is a situation or state of stalling or even stopping traffic caused by a large number of vehicles exceeding road capacity. Traffic congestion is a big problem that is often faced in Indonesia, especially in big cities. This study aims to analyze the factors that cause congestion in Jalan Gajah Mada Gunung Pangilun, Padang City. This research is quantitative descriptive by calculating traffic volume and the causes of traffic jams. And following the Urban Road Capacity Guidelines (PKJP, 2014). Based on the results of the field survey in Road Capacity (C) 3340 pcu / hour, Total Traffic Volume (Q) 1446 pcu / hour and Saturation Degree (DJ) 0.43 pcu / hour, so that the Road Service Level (LOS) type can be obtained B in the sense that traffic flow is stable, the speed starts to be influenced by traffic conditions, but can still be chosen according to the will of the driver. The highest level of congestion occurs on Wednesday, December 11, 2019 (from the day surveyed).

Estimation of Capacity of Urban Roads under Heterogeneous Traffic Conditions

Now-a-days, the traffic condition in India is of heterogeneous nature due to its dynamic nature. As the traffic onroads rises rapidly therefore, it is very essential to determine, prepare and design the roadway features accordingto the future .The objective of this paper is to estimate capacity for heterogeneous traffic condition. Estimationof traffic volume on road is relatively tough. Value of PCU can be used to measure the flow of traffic. Urbanroad of Nagpur i.e. from Hingna T-point to Chatrapati Square is selected to calculate its capacity. This studyemphasizes the need for capacity estimation to plan, design and control the rising vehicular population. Thetypes of roads and the agencies controlling it were characterized. The Inner Ring Road from Hingna T-point toChatrapati Square was divided into seven zones for the ease of study. Afterwards, the Traffic Volume study wasconducted by direct method of counting using tally sheets which is also called Paper and Pen method. The datacollected was used for calculation of PCU value. Then, using Selected Maxima method capacity of the stretchwas calculated and the effect of width on the capacity was studied and measures were suggested to improve thecapacity.

Urban mobility modeling to reduce traffic congestion in Surabaya: a system dynamics framework

Purpose This paper aims to address the urban mobility and traffic congestion problem under environmental dynamics to improve mobility and reduce traffic congestion using system dynamics (SD) simulation and scenarios. Design/methodology/approach SD simulation was used to analyze urban mobility and traffic congestion. Data were collected from the Transportation Department of Surabaya City. Several scenarios to improve urban mobility and reduce traffic congestion were developed by modifying the structures and parameters of the model. Findings Several factors influence urban mobility, including modal split, trip frequency, delay performance and the ratio of public transport supply and demand. Urban mobility, daily traffic and road capacity are some factors that affect traffic congestion. Scenarios can be designed based on the assumptions of the proposed strategy. Research limitations/implications The study was conducted at Surabaya City, East Java, Indonesia, which is the fourth most-congested city in the world. Practical implications By implementing several strategies (mass rapid transit and bus rapid transit development and public transport delay reduction), mobility performance is projected to be improved by 70.34-92.96%. With this increased mobility, traffic congestion is projected to decline by 52.5-65.8%. Originality/value The novel contributions of this research are: formulating relationships between several variables; modeling dynamic behavior of urban mobility and traffic congestion; and building scenario models to improve mobility and reduce traffic congestion in Surabaya. With the increase in urban mobility and the decrease in average daily traffic, traffic congestion could be reduced by a minimum of 57.6% and a maximum of 69%.

Developing Capacity Reduction Factors for Curbside Bus Stops Under Heterogeneous Traffic Conditions

Traffic characteristics of a roadway are significantly influenced by bus stops, and it becomes more chaotic when a separate bus bay is not provided and the bus has to be stopped in the curb lane. The present study analyzes the effect of such bus stops on the midblock capacity of urban arterials under heterogeneous traffic conditions. Field data have been collected at six sections of six-lane divided urban arterial roads; out of that, three sections have not marked with bus stop and referred to as base sections, whereas the other three have designated bus stops and denoted as friction sections. A set of simultaneous equations are established using speed and flow data to estimate the midblock capacity of urban roads and found to be 6000 PCU/h for one direction of flow. Further, a set of simultaneous equations are developed between the speed of a vehicle type and the densities of all categories of vehicles with densities of stopped buses in their individual terms. These equations are solved for any number of stopping buses at a fixed proportion of vehicles in the traffic stream for different traffic volume levels and thus get the capacity curves. It has been found that the capacity of urban arterials is reduced by 6.6–28.3% when the frequency of stopping buses is as low as 20 bus/h to as high as 120 bus/h, respectively. The study outcomes are useful for designing bus stops and at the same time estimating the capacity of such sections in order to reduce the congestion on the urban roadway network.