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Road Section (road + section)

Distribution by Scientific Domains

Engineering	28%

Selected Abstracts

Vehicle fatigue damage caused by road irregularities

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 5 2009
K. BOGSJÖ
ABSTRACT Road roughness causes fatigue-inducing loads in travelling vehicles. Road sections with a high degree of roughness are of special interest because these have a significant impact on vehicle's fatigue life. This study is focused on the statistical description and analysis of vehicle damage caused by irregularities. Standard statistical analysis tools are not straightforwardly applicable because of the non-stationary property of the irregularities. However, it is found that the road irregularities' influence on vehicles can be accurately described using a ,local' narrow-band approximation of the fatigue damage intensity. [source]

Contribution of intercepted subsurface flow to road runoff and sediment transport in a logging-disturbed tropical catchment

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 8 2008
J. N. Negishi
Abstract Hydrological and sediment fluxes were monitored for a 1 yr period in a tropical headwater catchment where a 3 yr old logging road caused substantial Hortonian overland flow (HOF) and intercepted subsurface flow (ISSF). On a 51·5 m road section, ISSF became an increasingly important component of total road runoff, up to more than 90% for large storms. The proportion of ISSF contributed by road cuts along more or less planar slopes compared with ISSF from a zero-order basin (convergent slopes) truncated by the road declined with increasing rainfall. During the monitored storms that generated ISSF along the road, on average, 28% of sediment export and 79% of runoff from the road section were directly attributable to ISSF. Estimates of total sediment export from the road surface (170 t ha,1 yr,1) and suspended sediment export from the logging-disturbed catchment (4 t ha,1 yr,1) were exceptionally high despite 3 yr of recovery. ISSF caused not only additional road-generated sediment export, but also exacerbated HOF-driven erosion by creating a poor foundation for vegetation recovery on the road surface. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Catchment-scale contribution of forest roads to stream exports of sediment, phosphorus and nitrogen

HYDROLOGICAL PROCESSES, Issue 23 2007
Gary J. Sheridan
Abstract The relative contribution of forest roads to total catchment exports of suspended sediment, phosphorus, and nitrogen was estimated for a 13 451 ha forested catchment in southeastern Australia. Instrumentation was installed for 1 year to quantify total in-stream exports of suspended sediment, phosphorus, and nitrogen. In addition, a total of 101 road,stream crossings were mapped and characterized in detail within the catchment to identify the properties of the road section where the road network and the stream network intersect. Sediment and nutrient generation rates from different forest road types within the catchment were quantified using permanent instrumentation and rainfall simulation. Sediment and nutrient generation rates, mapped stream crossing information, traffic data and annual rainfall data were used to estimate annual loads of sediment, phosphorus, and nitrogen from each stream crossing in the catchment. The annual sum of these loads was compared with the measured total catchment exports to estimate the proportional contribution of loads from roads within the catchment. The results indicated that 3·15 ha of near-stream unsealed road surface with an average slope of 8·4% delivered an estimated 50 t of the 1142 t of total suspended sediment exported from the catchment, or about 4·4% of the total sediment load from the forest. Stream discharge over this period was 69 573 Ml. The unsealed road network delivered an estimated maximum of 22 kg of the 1244 kg of total phosphorus from the catchment, or less than 1·8% of the total load from the forest. The average sediment and phosphorous load per crossing was estimated at 0·5 t (standard deviation 1·0 t) and 0·22 kg (standard deviation 0·30 kg) respectively. The lower proportional contribution of total phosphorus resulted from a low ratio of total phosphorus to total suspended sediment for the road-derived sediment. The unsealed road network delivered approximately 33 kg of the 20 163 kg of total nitrogen, about 0·16% of the total load of nitrogen from the forest. The data indicate that, in this catchment, improvement of stream crossings would yield only small benefits in terms of net catchment exports of total suspended sediment and total phosphorus, and no benefit in terms of total nitrogen. These results are for a catchment with minimal road-related mass movement, and extrapolation of these findings to the broader forested estate requires further research. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Data assimilation and inverse problem for fluid traffic flow models and algorithms

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2008
P. Jaisson
Abstract This article deals with traffic data assimilation and algorithms that are able to predict the traffic flow on a road section. The traffic flow is modellized by the Aw,Rascle hyperbolic system. We have to minimize a functional whose optimization variables are initial condition. We use the Roe method to compute the solution to the traffic flow modelling system. Then we compute the gradient of the functional by an adjoint method. This gradient will be used to optimize the functional. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Short-term prediction of motorway travel time using ANPR and loop data

JOURNAL OF FORECASTING, Issue 6 2008
Yanying LiArticle first published online: 28 MAY 200
Abstract Travel time is a good operational measure of the effectiveness of transportation systems. The ability to accurately predict motorway and arterial travel times is a critical component for many intelligent transportation systems (ITS) applications. Advanced traffic data collection systems using inductive loop detectors and video cameras have been installed, particularly for motorway networks. An inductive loop can provide traffic flow at its location. Video cameras with image-processing software, e.g. Automatic Number Plate Recognition (ANPR) software, are able to provide travel time of a road section. This research developed a dynamic linear model (DLM) model to forecast short-term travel time using both loop and ANPR data. The DLM approach was tested on three motorway sections in southern England. Overall, the model produced good prediction results, albeit large prediction errors occurred at congested traffic conditions due to the dynamic nature of traffic. This result indicated advantages of use of the both data sources. Copyright © 2008 John Wiley & Sons, Ltd. [source]

The road: An ethnography of the Albanian,Greek cross-border motorway

AMERICAN ETHNOLOGIST, Issue 1 2010
DIMITRIS DALAKOGLOU
ABSTRACT This article is an ethnographic study of a 29-kilometer stretch of cross-border highway located in South Albania and linking the city of Gjirokastër with the main checkpoint on the Albanian,Greek border. The road, its politics, and its poetics constitute an ideal point of entry for an anthropological analysis of contemporary South Albania. The physical and social construction, uses, and perceptions of this road uniquely encapsulate three phenomena that dominate social life in postsocialist South Albania: the transition to a market economy, new nationalisms, and massive emigration (mainly to Greece). Taking this cross-border road section as my main ethnographic point of reference, I suggest the fruitfulness of further discussion of the relationship between roads, narratives, and anthropology. [source]