Objective: Safety performance at bus stops is generally evaluated by using historical traffic crash data or traffic conflict data. However, in China, it is quite difficult to obtain such data mainly due to the lack of traffic data management and organizational issues. In light of this, the primary objective of this study is to develop a quantitative approach to evaluate bus stop safety performance.
Methods: The concept of level-of-safety for bus stops is introduced and corresponding models are proposed to quantify safety levels, which consider conflict points, traffic factors, geometric characteristics, traffic signs and markings, pavement conditions, and lighting conditions. Principal component analysis and k-means clustering methods were used to model and quantify safety levels for bus stops.
Results: A case study was conducted to show the applicability of the proposed model with data collected from 46 samples for the 7 most common types of bus stops in China, using 32 of the samples for modeling and 14 samples for illustration. Based on the case study, 6 levels of safety for bus stops were defined. Finally, a linear regression analysis between safety levels and the number of traffic conflicts showed that they had a strong relationship (R2 value of 0.908).
Conclusions: The results indicated that the method was well validated and could be practically used for the analysis and evaluation of bus stop safety in China. The proposed model was relatively easy to implement without the requirement of traffic crash data and/or traffic conflict data. In addition, with the proposed method, it was feasible to evaluate countermeasures to improve bus stop safety (e.g., exclusive bus lanes). 相似文献
China encourages the demonstration of carbon capture and storage (CCS) projects. In an effort to identify gaps and provide suggestions for environmental risk management of carbon dioxide (CO2) geological storage in China, this article presents a concise overview of potential health, safety and environmental (HSE) risks and environmental management regulations for CO2 geological storage in Australia, Japan, the United States (USA), the European Union (EU), and the United Kingdom (UK). The environmental impact assessment (EIA) experience of Shenhua Ordos Coal-to-Liquid (CTL) Project and PetroChina Jilin Oil Field enhanced oil recovery (EOR) is subsequently analyzed in light of our field investigation, and gaps in current EIA guidelines that are applicable to CO2 geological storage projects are identified. It is found that there are no specific environmental risk regulations suitable for CO2 storage in China, and environmental risk management lags behind the development of CCS technology, which presents a challenge to demonstration enterprises in terms of assessing environmental risk. One major challenge is the overestimation or underestimation of this risk on the part of the enterprise, and another is a lack of applicable regulations for government sectors to supervise the risk throughout CCS projects. Therefore, there is a pressing need for China to formulate environmental management regulations that include environmental risk assessment, mandatory monitoring schemes, environmental emergency plans, and related issues. 相似文献
Journal of Polymers and the Environment - Diclofenac sodium, as a typical deputation of non-steroidal anti-inflammatory drugs, is widely used in clinical treatment. Due to the heavy use, diclofenac... 相似文献