6 resultados para Road distance
em Universidad Politécnica de Madrid
Resumo:
Because of the high number of crashes occurring on highways, it is necessary to intensify the search for new tools that help in understanding their causes. This research explores the use of a geographic information system (GIS) for an integrated analysis, taking into account two accident-related factors: design consistency (DC) (based on vehicle speed) and available sight distance (ASD) (based on visibility). Both factors require specific GIS software add-ins, which are explained. Digital terrain models (DTMs), vehicle paths, road centerlines, a speed prediction model, and crash data are integrated in the GIS. The usefulness of this approach has been assessed through a study of more than 500 crashes. From a regularly spaced grid, the terrain (bare ground) has been modeled through a triangulated irregular network (TIN). The length of the roads analyzed is greater than 100 km. Results have shown that DC and ASD could be related to crashes in approximately 4% of cases. In order to illustrate the potential of GIS, two crashes are fully analyzed: a car rollover after running off road on the right side and a rear-end collision of two moving vehicles. Although this procedure uses two software add-ins that are available only for ArcGIS, the study gives a practical demonstration of the suitability of GIS for conducting integrated studies of road safety.
Resumo:
Questions relating to the transport of radioactive materials are very much an issue of current interest due to the increasing mobility of the materials involved in the nuclear fuel cycle, commitment to the environment, the safety and protection of persons and the corresponding regulatory legal framework. The radiological impact associated with this type of transport was assessed by means of a new data-processing tool that may be of use and serve as complementary documentation to that included in transport regulations. Thus, by determining the level of radiation at a distance of one metre from the transport vehicle and by selecting a route, the associated impacts will be obtained, such as the affected populations, the dose received by the most highly exposed individual, the overall radiological impact, the doses received by the population along the route and the possible detriment to their health. The most important conclusion is that the emissions of ionising radiation from the transport of radioactive material by road in Spain are not significant as regards the generation of adverse effects on human health, and that their radiological impact may be considered negligible.
Resumo:
Sight distance is of major importance for road safety either when designing new roads or analysing the alignment of existing roads. It is essential that available sight distance in roads is long enough for emergency stops or overtaking manoeuvres. Also, it is vital for engineers/researchers that the tools used for that analysis are both powerful and intuitive. Based on ArcGIS, the application to be presented not only performs an exhaustive sight distance calculation, but allows an accurate analysis of 3D alignment, using all new tools, from a Digital Elevation Model and vehicle trajectory. The software has been successfully utilised to analyse several two-lane rural roads in Spain. In addition, the software produces thematic maps representing sight distance in which supplementary information about crashes, traffic flow, speed or design consistency could be included, allowing traffic safety studies.
Resumo:
An integrated approach composed of a random utility-based multiregional input-output model and a road transport network model was developed for evaluating the application of a fee to heavy-goods vehicles (HGVs) in Spain. For this purpose, a distance-based charge scenario (in euros per vehicle kilometer) for HGVs was evaluated for a selected motorway network in Spain. Although the aim of this charging policy was to increase the efficiency of transport, the approach strongly identified direct and indirect impacts on the regional economy. Estimates of the magnitude and extent of indirect effects on aggregated macroeconomic indicators (employment and gross domestic product) are provided. The macroeconomic effects of the charging policy were found to be positive for some regions and negative for other regions.
Resumo:
Sight distance plays an important role in road traffic safety. Two types of Digital Elevation Models (DEMs) are utilized for the estimation of available sight distance in roads: Digital Terrain Models (DTMs) and Digital Surface Models (DSMs). DTMs, which represent the bare ground surface, are commonly used to determine available sight distance at the design stage. Additionally, the use of DSMs provides further information about elements by the roadsides such as trees, buildings, walls or even traffic signals which may reduce available sight distance. This document analyses the influence of three classes of DEMs in available sight distance estimation. For this purpose, diverse roads within the Region of Madrid (Spain) have been studied using software based on geographic information systems. The study evidences the influence of using each DEM in the outcome as well as the pros and cons of using each model.
Resumo:
The introduction of a homogeneous road charging system according to the Directive 2011/76/EU for the use of roads is still under development in most European Union (EU) member states. Spain, like other EU members, has been encouraged to introduce a charging system for Heavy Goods Vehicles (HGVs) throughout the country. This nationwide charge has been postponed because there are serious concerns about their advantages from an economic point of view. Within this context, this paper applies an integrated modeling approach to shape elastic trade coefficients among regions by using a random utility based multiregional Input- Output (RUBMRIO) approach and a road transport network model in order to determine regional distributive and substitutive economic effects by simulating the introduction of a distance-based charge (?/km) considering 7,053.8 kilometers of free highways linking the capitals of the Spanish regions. In addition, an in-depth analysis of interregional trade changes is developed to evaluate and characterize the role of the road charging approach in trade relations among regions and across freight intensive economic sectors. For this purpose, differences in trade relations are described and assessed between a base-case or ?do nothing? scenario and a road fee-charge setting scenario. The results show that the specific amount of the charge set for HGVs affect each region differently and to a different extent because in some regions the price of commodities and the Generalized Transport Cost will decrease its competiveness within the country.