Highway toll and air pollution: Evidence from Chinese cities

Most highways in urban China are tolled to finance their construction. During the eight-day National Day holiday in 2012, highway tolls were waived nationwide for passenger vehicles. We use this to identify the effects of highway tolls on air pollution. Using daily pollution and weather data for 98 Chinese cities in 2011 and 2012 and employing both a regression discontinuity design and differences-in-differences method with the 2011 National Day holiday as a control, we find that eliminating tolls increases pollution by 20% and decreases visibility by one kilometer. We also estimate that the toll elasticity of air pollution is −0.15. These findings complement the scant literature on the environmental impact of road pricing.     

公路项目施工期环评要点分析

本文首先介绍公路项目施工期环评的现实意义,之后阐述公路项目施工期环评要点,以此强化公路项目施工期环评水平及其环保效益。     

谈公路运输突发性环境污染事故应急监测

针对公路危险化学品运输车辆泄漏突发性环境污染事故发生突然、危害严重等特点,阐述了应急监测在污染事故中的关键作用。要求环境监测部门迅速反应,进行快速监测,并报出监测结果,为污染物的控制提供科学依据。本文为公路运输突发性环境污染事故应急监测提出了建议和要求。     

吴忠黄河公路大桥建设对滨河湿地的影响及保护措施研究

跨河大桥的建设对社会和经济的发展具有促进作用，但同时也会影响环境。正在建设的吴忠黄河公路大桥穿越吴忠滨河湿地，会对湿地的生态环境产生影响。文章介绍了吴忠黄河公路大桥和滨河湿地的基本概况，分析了大桥建设和营运对滨河湿地环境的影响，并提出了滨河湿地生态环境保护措施。     

青藏公路路堤边坡水土保持措施及效益分析

公路建设加速了区域的原有侵蚀，为了摸清公路边坡的侵蚀特征，寻找有效的防治措施，在青藏公路边坡布设不同水土保持措施的径流观测小区，进行了两年的观测（2003年和2004年），结果表明：（1）工程措施具有较好的水土保持效益，其减流（减沙）效益在第一年和第二年分别达到3883％（8189％）和48.72％（9581％），其中截排水措施的水土保持效益一方面说明公路路面来水也是边坡侵蚀的重要动力，有效拦截路面来水将会极大地减少径流和泥沙，另一方面也说明要提高公路边坡土壤侵蚀的预测能力，应该将路面来水作为重要的驱动力之一；（2）植被措施可以起到一定的减流减沙效果，其中人工植被措施有很大的潜力，其减蚀效益都在50％以上；（3）综合措施表现出了极好的水土保持效益（减流在40％以上，减沙在97％以上），尤其土工格室+植被措施，兼具水土保持与景观双重效益。该研究可以为青藏高原地区的水土保持设计和生态环境保护规划提供数据支持。〖     

Modelling vegetation greenness responses to climate variability in a Mediterranean terrestrial ecosystem

Accurate knowledge of the quality and environmental impact of the highway runoff in Pear River Delta, South China is required to assess this important non-point pollution source. This paper presents the quality characterization and environmental impact assessment of rainfall runoff from highways in urban and rural area of Guangzhou, the largest city of Pear River Delta over 1 year’s investigation. Multiple regression and Pearson correlation analysis were used to determine influence of the rainfall characteristics on water quality and correlations among the constituents in highway runoff. The results and analysis indicates that the runoff water is nearly neutral with low biodegradability. Oil and grease (O&G), suspended solids (SS) and heavy metals are the dominant pollutants in contrast to the low level of nutrient constituents in runoff. Quality of highway runoff at rural site is better than that of at urban site for most constituents. Depth and antecedent dry period are the main rainfall factors influencing quality of highway runoff. The correlation patterns among constituents in highway runoff at urban site are consistent with their dominant phases in water. Strong correlations (r ≥ 0.80) are found among chemical oxygen demand (COD), total phosphorus, Cu and Zn as well as conductivity, nitrate nitrogen and total nitrogen. O&G, COD, SS and Pb in highway runoff at urban site substantially exceed their concentrations in receiving water of Pear River. The soil directly discharged by highway runoff at rural site has contaminated seriously by heavy metals in surface layer accompanying with pH conversion from original acidic to alkaline at present.     

公路建设项目声环境后评价方法研究及其应用

通过对公路建设项目声环境后评价的概念和目的的讨论，对声环境后评价的主要内容作了较系统的研究，提出了公路建设项目声环境后评价的方法，重点介绍了声环境后评价的监测与调查和验证分析的方法，并将其应用到深汕西高速公路的环境影响后评价之中。     

高速公路对沿途土地利用及景观格局的影响——以内蒙古省道103线蒲滩木刀口到城壕段为例

利用2002年和2006年公路建设前后的两期遥感数据,分析了公路对沿线土地利用和景观格局的影响。结果表明：公路建设使公路用地面积增加了4.10km^2,主要由侵占农业用地和沙地所导致;居民区、森林面积分别增加了1.12km^2和0.08km^2,其余土地利用类型面积有所减少;道路、居民区和森林的景观破碎化指数增加,农田、草地、灌木、沙地和水域下降;景观多样性指数增加,景观优势度降低。     

Efficacies of roadway safety improvements across functional subclasses of rural two-lane highways

Introduction

Highway crash occurrence is a leading cause of unnatural deaths, and highway agencies continually seek to identify engineering measures to reduce crashes and to assess the efficacy of such measures. Most past studies on the effectiveness of roadway improvements in terms of crash reduction considered all rural two-lane sections as a single category of roads. However, it may be hypothesized that the differences in the mobility and accessibility characteristics that are reflected in (and due to) the different design standards between different functional subclasses in the rural two-lane highway system can lead to differences in efficacies of safety improvements at these subclasses. This paper investigates the efficacy of roadway improvements, in terms of crash reduction, at the various subclasses of rural two-lane highways.

Methods

An empirical analysis of safety performance at each of the three subclasses of rural two-lane highways was carried out using the negative binomial modeling technique. For each subclass, crash prediction models were developed separately for the three levels of crash severity: property-damage only, injury, and fatal/injury. The crash factors that were considered include lane width, shoulder width, pavement surface friction, pavement condition, and horizontal and vertical alignments. After having developed the safety performance functions, the effectiveness (in terms of the extent of crash reduction, for different levels of crash severity) of highway safety enhancements at each highway subclass were determined using the theoretical concepts established in past literature. These enhancements include widening lanes, widening shoulders, enhancing pavement surface friction, and improving the vertical or horizontal alignment.

Results and Conclusion

The study found that there is empirical evidence to justify the decomposition of the family of rural two-lane roads into its constituent subclasses for purposes of analyzing the effectiveness of safety enhancement projects and thus to avoid underestimation or overestimation of benefits of safety improvements at this class of highways.     

新疆天山公路泥石流风险评价研究

结合泥石流危险度和公路受泥石流损毁度两个指标,构建了天山公路泥石流风险评价模型,实现了对天山公路全线主要泥石流沟的风险值量化:风险值大于0.80的为极度危险,应以防为主,治为辅;风险值在0.50～0.80之间的为高度危险,应防、治并重;风险值在0.25～0.60之间的为中度危险,应以治为主,防为辅;风险值小于0.25的为轻度危险,应以防为主,治为辅。