Roads, Railroads, and Decentralization of Chinese Cities

PurposeTo establish a stimulating traffic model of ring road systems and study the traffic effects of ring road in the center of a large city, including the influence in vehicle's travel time and distance.Design/methodology/approachDifferent from the ring road systems in the west, Beijing and other big cities in China build ring roads in city center. However, it seems that those systems do not work because the traffic problem still exists when the number of cars in the city increased quickly in past five years. According to the real geographic topology network structure around Er Huan road in Beijing city center, a simplified simulated traffic model was built. Then, two indices of traffic effects, average travel time and path length were studied by comparing the two models with or without ring road.FindingsAccording to the simulation, although a high‐speed ring road shortens the travel time, it isolates the nature road network system and increases travel distance in the city center. Furthermore, it is uneconomic building a ring road to relieve traffic jams.Research limitations/implicationsOnly Er Huan road in Beijing traffic system was simulated in the model. A more complicated ring road system needs to be developed.Practical implicationsA useful model for optimizing traffic system with ring roads, and providing a support for doubting the strategy of developing ring road in city center district in many cities of China.Originality/valueThis is a new way by establishing the simulation model to analyze the scheme of ring road traffic systems. Furthermore, advice for current situation are concluded and it is useful for optimizing current traffic system.

This paper analyses the carbon dioxide emissions from home-based commuter traffic in Xi'an, a typical rapidly growing city in China. The results show that increases in car availability, household annual income and the number of parking facilities all increase emissions, while increases in population density and number of public transport routes reduce them. Housing areas separated from the city centre by ring roads are found to be significant contributors to emissions, particularly higher between the second and the third ring roads while lower inside the first ring road. It is also found that the ‘70–20 emissions’ rule exists in Xi'an, which implies high emitters contribute more to emissions, and people working in government emit more than others, which implies that improving the awareness of low-carbon dioxide emission among public servants is important. The findings indicate that the focus of emissions reduction should be on these high emitters, who have car availability and high incomes, work in the government and live outside the downtown districts, along or outside the ring roads, or along radial roads. The findings could be useful for other cities aiming to develop transportation with low carbon dioxide emissions.

Assessment of resident's exposure level and health economic costs of PM10 in Beijing from 2008 to 2012

BackgroundThe Antwerp ring road has a traffic density of 300,000 vehicles per day and borders the city center. The ‘Ringland project’ aims to change the current ‘open air ring road’ into a ‘filtered tunneled ring road’, putting the entire urban ring road into a tunnel and thus filtering air pollution. We conducted a health impact assessment (HIA) to quantify the possible benefit of a ‘filtered tunneled ring road’, as compared to the ‘open air ring road’ scenario, on air quality and its long-term health effects.Materials and MethodsWe modeled the change in annual ambient PM2.5 and NO2 concentrations by covering 15 kilometers of the Antwerp ring road in high resolution grids using the RIO-IFDM street canyon model. The exposure-response coefficients used were derived from a literature review: all-cause mortality, life expectancy, cardiopulmonary diseases and childhood Forced Vital Capacity development (FVC).ResultsOur model predicts changes between -1.5 and +2 μg/m³ in PM2.5 within a 1,500 meter radius around the ring road, for the ‘filtered tunneled ring road’ scenario as compared to an ‘open air ring road’. These estimated annual changes were plotted against the population exposed to these differences. The calculated change of PM2.5 is associated with an expected annual decrease of 21 deaths (95% CI 7 to 41). This corresponds with 11.5 deaths avoided per 100,000 inhabitants (95% CI 3.9–23) in the first 500 meters around the ring road every year. Of 356 schools in a 1,500 meter perimeter around the ring road changes between -10 NO2 and + 0.17 μg/m³ were found, corresponding to FVC improvement of between 3 and 64ml among school-age children. The predicted decline in lung cancer mortality and incidence of acute myocardial infarction were both only 0.1 per 100,000 inhabitants or less.ConclusionThe expected change in PM2,5 and NO2 by covering the entire urban ring road in Antwerp is associated with considerable health gains for the approximate 352,000 inhabitants living in a 1,500 meter perimeter around the current open air ring road.

Urban-rural and temporal differences of woody plants and bird species in Harbin city, northeastern China

Selecting ecologically appropriate scales to assess landscape ecological risk in megacity Beijing, China

To identify network bottlenecks of urban expressway effectively is a foundational work for improving network traffic condition and preventing traffic congestion. This study proposes a methodology to estimate the impact of traffic incident on urban expressway on the basis of modified cell transmission model. The metastable state was taken into account in the proposed method to reflect the actual operating state of traffic flow on urban expressway as much as possible. Regarding the location of traffic incident, the method of cell restructuring settings was discussed. We then proceed to introduce a new concept of the effected length in a given time period as the evaluation indicator to directly depict the influence of traffic incident. The proposed method was tested on a 6516-meter urban expressway section of west second ring road in Beijing. The simulation results indicated that the proposed methodology performs well to predict the impact of traffic incident on urban expressway.

Recurring bottlenecks significantly contribute to urban freeway congestion, making their analysis essential. This study examines six bottlenecks on Beijing’s Ring Road using multi-day data, identifying them via Dynamic Time Warping and Fuzzy C-Means Clustering (DTW+FCM). Key parameters—free-flow speed, critical speed, critical density, and jam density—are calibrated using fundamental diagram models. The Weibull distribution analyzes flow and speed patterns during congestion phases. The DTW+FCM method effectively identified bottlenecks and congestion levels. Severe congestion lasting over 10 hours on the West Second and Third Ring Roads averaged speeds of 15 km/h. The S3 model best fits data for the West Ring Roads, while the Van Aerde model suits the North Ring Roads. Different methods yield varying traffic capacity estimates, highlighting the need for nuanced approaches in urban expressway planning to maintain traffic quality and comfort. These findings offer valuable guidance for research and practical traffic management solutions.

Policy, innovation, market or behavior driven effects: Energy green transition and environmental management in Chinese heterogeneous cities

Evaluation and empirical research on the energy efficiency of 20 mining cities in Eastern and Central China

The concentration of economic activity in town centres requires a good transportation system which is however restricted often by the necessity to preserve historical significant buildings and street patterns. Responsible planners must therefore connect the old structures to modern ones in a manner which will guarantee economical circulation in town centres. The maintenance of these functions depends in each individual case upon a thorough knowledge of the interdependence of traffic-structure and environment. Several traffic studies by the author show the following results: 1. The clearance from town-centres of all transport of persons and goods not directly designated for the centre can be achieved by the construction of ring and tangential roads. 2. The efficient coordination of traffic and parking policies, thus insuring the traffic flow in town centres, can be accomplished efficiently by the provision of sufficient parking space within and outside the ring roads. 3. As the cost and importance of land in city centres increases, the parking time within should be reduced. Free and unlimited parking in areas of high land cost is unreasonable, and, in the long run, impossible. 4. The quality of public transportation from the outskirts to the centre needs to be improved as the town grows. 5. Vehicular traffic cannot be completely excluded from city centres. But the creation of pedestrian zones is still desirable. 6. Many individual measures will contribute to an amelioration of trafficflow and capacity in city centres: a) segregation of public and private transportation b) one-way-street systems, and c) improved intersection design and coordination of traffic signals.

The road network in the city center is a critical element, not only for ensuring a comfortable and healthy lifestyle but also for fostering economic development. Therefore, road networks must meet standards of effectiveness, speed, comfort, and safety. However, achieving these standards can be challenging for some cities, such as Amasya. Amasya, a historically small city in Turkey, faces limitations in expanding road capacity or constructing new roads due to its geographical conditions. Instead, a ring road has been constructed around Amasya's city center to alleviate traffic congestion. This study investigates the impact of the newly opened ring road on urban traffic in Amasya. Manual traffic data for 26 links in Amasya's city center were collected over 11 hours (from 7 AM to 6 PM) before and after the ring road was opened. Under three different assumptions, 1-hour traffic flows for these links were estimated, and subsequent comparisons were made between traffic data obtained at two different times. The findings indicate a decrease in traffic for 92% of the links after the ring road's opening, with more than a 20% reduction observed in 35% of the roads. Statistical support for this decrease is provided by the paired t-test at a 95% confidence level. Additionally, taking into account seven pollutants, including Carbon Monoxide (CO), Hydrocarbons (HC), Nitric Oxide (NOx), Particulate Matter (PM), and Sulfur Oxide (SOx), a 6.6% reduction in traffic-related air pollution was found following the opening of the ring road.

As many as 99% of national logistics transportation using land routes. To accommodate the need for logistics, the development of ring road is an efficient solution, especially to prevent the distortion of activities within the city. Likewise with Salatiga City, the construction of Salatiga’s South Ring Road aims to reduce congestion on the main road in the city center. Of course, the existence of the ring road is affecting land use change in Salatiga City, especially in areas passed by the ring road. Therefore, the research question is how the relationship between the ring road and land use transformation in Salatiga City. While the purpose of this research is to identify the form of relationship between the ring road and land use transformation in Salatiga City.

One of the prime objectives of this study is to evaluate the differences between the night time and the day time merging traffic stream characteristics by analyzing the merging traffic survey data covering night time and day time as well as congested and non-congested traffic conditions. A previously developed merging traffic computation model considering multi-merging phenomena was applied to evaluate the traffic in terms of merging probability.

With the urban expansion and economic restructuring, the jobs-housing relationship has become an important issue in studies on urban spatial structure. This paper employed a job accessibility model, which is an evaluation instrument to measure the jobs-housing relationship in Beijing Metropolitan Area from a job accessibility perspective. The results indicate that the population in the central city is declining, whereas the population in the suburbs is consistently growing and forming new population centers. However, the distribution pattern of employment is still highly centralized. Job accessibility varies in different locations, but the inner-city areas (within the Third Ring road) have seen improved job accessibility over time while job accessibility in the suburbs (especially outside the Fourth Ring road) has decreased, and this has led it to become a primary area of residential and employment mismatch. At the same time, the new towns in the outer suburbs have not yet demonstrated great potential to attract more jobs. In addition we find that, to some extent, urban planning changes the jobs-housing relationship, but a polycentric urban spatial structure is not yet evident. The floating population and related housing policy also affect the jobs-housing relationship. We propose some measures to resolve the spatial mismatch as well as some future research directions.