居住区路网模式研究

居住区的路网模式是关系城市道路和居住区内部交通运行效率的重要环节，文章分析了国外相关理论的发展历程。并从路网的形式、间距等方面将居住区路网模式分为41类，并选取几类代表性的模式进行了相关解析。     

居住区管网平面布局与绿化的关系

一、居住区绿化用地分析 国家要求居住区的绿地率达到30%,人均公共绿地3平方米(其中:居住小区公共绿地1.0M~2/人,居住区级公共绿地2.0M~2/人)。经对唐山市24个居住小区调查:列入用地平衡表的居住小区公共绿地人均0.75M~2,居住区级公共绿地人均0.12M~2。这两项用地占居住区用地的4.76%。显然依靠这点园林绿化面积去达到绿化、美化环境,提高环境质量是微不足道的。唯一可大做绿化“文章”的是占居住区用地约30%的楼间空地,再加上居住小区及居住区级公共绿地,居住区的绿地率可达30%以上,能基本满足居住     

居住区动态交通系统的发展模式探索

本文以居住区规划设计中的动态交通为主题．结合国外居住区中道路系统的发展演变过程中总结出的一些经验模式,结合我国的国情以及居住区规划中存在的具体问题,寻求出一条适合我国国情的居住区道路系统规划模式．使居住区内部的路网结构在发挥其交通功能的同时．体现出人的活动的主体作用,坚持以人为本的设计原则．进而营造舒适美好的居住环境。     

浅议晋中市新城组团路网规划

从城市交通、经济、城市功能、城市生态方面分析了宽道路—大街区—稀路网带来的问题，并提出了解决问题的方法，论述了晋中市新城路网规划的模式，以解决各类城市问题，达到人与城市的和谐发展。     

城市居住区地下空间开发利用探讨

城市居住区地下空间的开发利用是城市建设和经济发展到一定阶段，出现土地紧张和环境恶化结果后的一种解决方案。本文针对城市居住区地下空间的开发利用的综合效益、功能规划、开发模式等进行分析和探讨，以期能对未来居住区地下空间的开发提供一条前瞻性的构想。     

居住区道路系统与交通安全

作者从两个方面讨论了居住区道路系统规划与交通安全之间的关系。一是通过分析典型居住区路网形式的人车分流状况和道路面积率水平,指出对居住区路网形式的选择一定程度上是在交通安全与土地利用的合理性之间寻找平衡点。二是指出居住区不同位置应采用不同的交通安全标准,提出满足上述标准的部分规划措施。     

城市居住区内部交通系统优化的策略分析

城市居住区是城市空间的重要组成部分,是居住者日常生活的主要空间,居住区内部的交通系统在居住空间中扮演着重要的角色,文章从交通系统的道路布局、车辆控制及道路尺度等方面探讨居住区交通系统的优化策略。     

城市居住区地下空间开发利用探讨

城市居住区地下空间的开发利用是城市建设和经济发展到一定阶段 ,出现土地紧张和环境恶化结果后的一种解决方案。本文针对城市居住区地下空间的开发利用的综合效益、功能规划、开发模式等进行分析和探讨 ,以期能对未来居住区地下空间的开发提供一条前瞻性的构想     

基于小街区制的合理路网密度探讨

在分析路网密度与街区尺度的关系以及小街区模式下影响街区尺度界定的基础上,研究了小街区模式下方便市民慢行出行的适宜路网密度,得出小街区模式下街道间距100 m～200 m较为适宜,路网密度10 km/km~2～16 km/km~2,此时单个街区面积在1 hm~2～4 hm~2内。     

城市居住区规划中的抗震防灾问题研究

随着我国经济的发展,城市化进程不断加快,城市居住区居住着我国50%以上的人口,拥有我国2/3以上的财富,因此,城市居住区的抗震防灾能力直接关系着我国城市的发展和国家的命运,这就需要加强城市居住区的抗震防灾能力。主要分析目前我国城市居住区抗震防灾规划现状和抗震防灾规划在抗震设防中的地位和作用,提出了提升城市居住区抗震防灾规划水平,旨在提高我国城市居住区的抗震防灾能力。     

Projecting transition probabilities for regular public roads at the ecoregion scale: A Northern Appalachian/Acadian case study

Existing roads have far-reaching effects on biodiversity, and therefore road network expansion is of critical concern to conservation planning. Road density trend analysis is often too coarse and assumes homogeneous landscapes, whereas spatial transition probability analysis captures landscape variability typical of ecoregions. Simple models for projecting road network growth will assist planning agencies and conservation organizations to guide protection efforts. We investigate growth of regular public roads in the State of Maine over a 17-year historical period, and then use the best-selected (AIC) logistic regression model to validate and then project spatial probability of future roads to the Northern Appalachian/Acadian ecoregion. Nearly 2000 km of new roads were constructed in settled landscapes in Maine 1986–2003, influencing 37,000 ha of adjacent habitats. The majority (93.5%) of the new roads performed local functions and were short (<1/3 km in length), characterized as residential roads typical of sprawl. The best-selected logit model [dwelling density (+), elevation (−), distance to urban area (−), distance to existing primary/secondary highway (−)] captured 84% of reserved new road points in Maine, and only 27% of random points at the >0.5 probability level. The projected model forecasts 0.5 million km of new residential public roads in the Northern Appalachian/Acadian ecoregion for the next two decades, suggesting that cumulative effects of residential road network expansion are a serious region-scale biodiversity threat.     

Regional analysis of the effect of paved roads on sodium and chloride in lakes

Salinization of surface water from sodium chloride (road salt) applied to paved roads is a widely recognized environmental concern in the northern hemisphere, yet practical information to improve winter road management to reduce the environmental impacts of this deicer is lacking. The purpose of our study was to provide such information by developing baseline concentrations for sodium and chloride for lakes in watersheds without paved roads, and then determining the relationship between these ions and density, type, and proximity of paved roads to shoreline. We used average summer (June-September) sodium and chloride data for 138 lakes combined in a watershed based analysis of paved road networks in the Adirondack Park of New York, U.S.A. The watersheds used in our study represented a broad range in paved road density and type, 56 of which had no paved roads. Median lake sodium and chloride concentrations in these 56 watersheds averaged 0.55 and 0.24 mg/L, respectively. In contrast, the median sodium and chloride concentrations for the 82 lakes in watersheds with paved roads were 3.60 and 7.22 mg/L, respectively. Paved road density (lane-km/km²) was positively correlated with sodium and chloride concentrations, but only state roads were significantly correlated with sodium and chloride while local roads were not. State road density alone explained 84 percent of the variation in both ions. We also successfully modeled the relationship between road proximity to shoreline and sodium and chloride concentrations in lakes, which allowed us to identify sections of road that contributed more to explaining the variation in sodium and chloride in lakes. This model and our approach could be used as part of larger efforts to identify environmentally sensitive areas where alternative winter road management treatments should be applied.     

山地城市道路规划刍议

山地城市地形、地质条件复杂,道路选形应依据道路等级和性质而定,采用曲线形设计方法,避开不良地质带;道路竖向规划应注意平面线形与纵面线形的协调;道路网络布局应追求自由式、组团式。城市各组团间应加强车流集散通道和人流集散通道建设,组团内部应合理规划支路,采用立交方式提高道路通行能力。     

Characteristics of road network forms in historic districts of Japan

This study focused on the structure and the platform of the road space of historic districts. We analyzed the road networks of 16 historic districts in Japan from the perspectives of circularity, accessibility and indirection based on graph theory. By calculating and comparing the indexes of each road network (NW1 and NW2) forms, we quantitatively describe the effects of the main prefectural roads (more than 4 m in width) and narrow streets (less than 4 m in width) on the spatial characteristics. And it turned out that we could divided the 16 objective historic districts into 4 types. Moreover, we qualitatively studied the characteristics of each type of historic districts based on their development background and the structure of road network.     

Cultural Heritage of Roads and Road Landscapes: Classification and Insights on Valuation

Over time roads and their surroundings gained historic and cultural significance. This significance is oftentimes acknowledged and numerous roads and road infrastructure objects with their surrounding environment are listed and protected. Notwithstanding this, it is necessary to note that the ways in which roads, their surrounding environment, and adjacent objects can manifest heritage values, can be complex, and are not limited to historic roads or historic road landscapes. Different categories of these ways can be distinguished: road landscape can be recognized as cultural heritage, cultural heritage objects functionally related or unrelated to the road can exist in its surrounding environment, and roads can also be treated as cultural heritage objects in landscape. Understanding the dimensions of the cultural heritage of roads and road landscapes and analysing its values can be important not only to the environmental, technological, and cultural history, but also to the future-oriented heritage management and territorial planning fields. The article is aimed to present a framework for analysing the cultural heritage of the automobile roads and road landscapes consisting of the system for its classification and of identification of factors determining its cultural value and the categories of economic value it can provide. Assessment possibilities of these values are also shortly discussed.     

Assessment of road instability along a typical mountainous road using GIS and aerial photos, Lebanon – eastern Mediterranean

The steeply sloping and mountainous nature of the Lebanese territory gives rise to a spectrum of natural hazards. It is a rugged area cut by a dense network of roads connecting scattered but highly populated cities. The roads experience heavy traffic. They often follow geological formations of weak lithologies and cross fault systems inducing recurrence of mass movements. When the rather poor road construction in Lebanon is added to this, the result is a potential risk to life as well as economic losses. The purpose of this study was to investigate the interactive components determining the hazards affecting the highway between Beirut and Broummana (Mount Lebanon). It specifically aims to show, with the aid of GIS and aerial photographs, the integration of datainput from those components for optimizing approaches to highway hazard analysis. Electronic Publication     

Edge effects of roads on temperature, light, canopy cover, and canopy height in laurel and pine forests (Tenerife, Canary Islands)

The estimation of the road edge effect is useful to understand changes induced by the road network on ecosystems. Road networks on islands may break ecosystem integrity through microclimate edge effects, which are known to be associated with disturbances to animal and plant communities. Road edge effects have been scarcely studied on oceanic islands. In this paper we studied road edge effects on microclimate and canopy structure in laurel and pine forests in Tenerife (Canary Islands). We assessed depth of road edge effect for temperature at four vertical layers (soil, litter and air at 5 cm and 1.3 m above ground), light intensity, canopy cover and height, in transects running from narrow (6–7 m width) asphalt roads and dust trails to 100 m to the interior of both forests. We used an ANOVA procedure with Helmert difference contrasts to identify the distances along transects over which edge effects were significant. We detected significant gradients for most parameters but they were consistently narrow both within and between forests. In the laurel forest, we detected highly significant gradients for soil temperature, light, and canopy cover and height in both asphalt and unpaved roads. In the pine forest, we detected a highly significant gradient for soil temperature at asphalt roads, and a significant light gradient for both asphalt and unpaved roads. From the road edge to the forest interior, significant temperature changes persisted for only 3 m, light variation persisted for 6 m, and canopy cover and height changed significantly within the first 10 m. Asphalt roads and dust trails revealed different patterns of variation for temperature between edge and interior. No differences were found between the two types of roads in edge-interior trends for light or canopy structure. The abruptness of microclimate and canopy gradients was slightly higher in the laurel forest than in the pine forest, caused by a higher edge contrast in the former. The depth of the road edge effect found in laurel and pine forests was small, but it could have cumulative effects on forest microclimate and forest associated biota at the island scale. Such changes deserve attention by local road managers for planning and design purposes.     

A further discussion of the factors controlling the distribution of Pt, Pd, Rh and Au in road dust, gullies, road sweeper and gully flusher sediment in the city of Sheffield, UK

Forty paired road dust and gully sediments from the city of Sheffield in NE England show that high platinum, palladium and rhodium concentrations derived from catalytic converters depend on proximity to both roundabouts rather than traffic lights and to topographic lows. Road dust outside schools and control samples, further away on the same road, show that Pt, Pd and Rh concentrations are dependant on passing traffic flow rather than numbers of stopping vehicles. Highest values of Pt + Pd in road dust are 852 ppb and 694 ppb in gullies. Rh has maximum values of 113 ppb in road dust and 49 ppb in gullies. Pt and Pd values of a few ppb to just over 100 ppb occur in road dust where traffic does not stop, on roads away from junctions. Pt, Pd, Rh and Au are all picked up by road sweepers and gully flushers both with maximum values of just over 100 ppb Pt and Pd. High Au values (maximum 610 ppb in a road dust) were located on pavements, in suburbs, outside schools and in road sweepers collecting in residential areas rather than on high traffic flow roads. Stratification of Pt and Pd in gullies was not observed whereas a high Au value was recorded at the bottom of a gully suggesting gravity concentration for Au. Anomalous Pd grades of 1050 ppb in road dust from a school entrance and 2040 ppb in a street sweeper sample were recorded. These high Pd- and Au-bearing samples do not have anomalous Pt or Rh values and may be sourced from jewellery or dental fillings. However, most samples have consistent Pt/Pd ratios of about 1 and Pt/Rh values of 4 to 5 indicating a catalytic converter source. Pt and Pd are concentrated in road dust at levels well above background in all the samples, including on high and low traffic flow roads.     

道路生态学融注城市道路景观规划初探——以武汉花山生态新城为例

该文首先指出道路生态景观建设是体现花山生态新城的重要表征,然后定位了花山生态新城道路系统生态景观总特征,尝试从道路生态学的角度,对花山滨水道路、路边植物、路面、亮化、道路休闲等几个方面初步探讨道路生态景观营建的措施,对今后道路生态景观建设起到参考作用。     

关于城市道路网规划设计的一些问题与思考

针对城市道路交通效能低下、交通拥堵的现状,从道路网规划理念、道路与周边土地开发利用关系、道路网密度、道路文明等几个方面探讨了城市道路网规划设计中存在的一些问题,以此提高我们对城市道路网规划设计的认识。