Relationship between predicted speed reduction on horizontal curves and safety on two-lane rural roads in Spain

According to different studies, speed reduction is considered one of the major factors in contributing road safety. For that reason, several guidelines have been recommended for maximum desirable speed reductions from tangents to horizontal curves and for maximum differentials between design and operating speeds on horizontal curves. The Interactive Highway Safety Design Model (IHSDM) Design Consistency Module presents an analysis of the relationship between speed reduction and crashes for horizontal curves on U.S. two-lane rural highways. This paper presents the relationship between speed reduction and crashes for horizontal curves on Spanish two-lane rural roads. A model for using regression analysis to predict crashes is presented. Exposure, curve length (CL), and difference in 85th-percentile speeds (δV85) between successive tangents and horizontal curves, as well as between successive curves, are used. The model's coefficients were different from the ones obtained for U.S. highways, although the values of the goodness-of-fit criteria were similar. In addition, the relationship between crashes and different speeds is analyzed, taking the difference in speed as a speed differential not exceeded by 85% of the drivers traveling under free-flow conditions (δ85V), instead of considering it as δV85. The two models (δV85 versus δ85V) give very similar results

Feasible Use of Recycled Concrete Aggregates with Alumina Waste in Road Construction

The management of different industrial by-products, such as recycled aggregates from construction and demolition waste and alumina by-products, as well as the reduction of landfill deposits by incorporating these products in a second life cycle, were the focus of this work. The aim of this study was to demonstrate the technical viability of using these waste and by-product as a material for road pavement base layers. For this purpose, a real-scale application was carried out, and the behavior of three types of materials, applied on a section of an experimental road under real vehicle traffic conditions, was studied and compared. Three materials were used in these sections applied in the road sub-bases. First, a control material composed of a type of artificial gravel was used to be compared with the rest of materials; the second material was composed of recycled aggregates, and the third was composed of a mix of recycled aggregates and alumina waste. The results concluded that the effectiveness of the sections built using recycled aggregates and alumina waste was very positive and similar those constructed using natural aggregates.Isolux-Corsan Constructio

Transit quality evaluation: processes conducted by managers and operators

The development of quality policies applied to the public transport sector has increased the operators and managers interest in ensuring passengers’ satisfaction standards; therefore, their actions have been instrumented through the quality of service perception. In this context, the research project GESCAL performs a comparative analysis about the evaluation techniques used by the operators, from the passengers’ point of view, as a tool that support the service quality management. This comparison shapes the innovative nature of this research. This paper presents, the diversity of procedures carried out at a national level for evaluating passengers’ perceptions about the transit service quality. Some conclusions are obtained through a qualitative analysis based on in-depth interviews conducted to operators and administrations of different public transport services (bus, train, tramway and light rail services in the urban, metropolitan and interurban contexts).These results permit to affirm that these procedures are to a large extent standardized, but the implemented methodologies are heterogeneous between organizations due to the influence of the exogenous context and different endogenous factors of the organization. Likewise, the objectives of the quality evaluation service campaigns can be affected by these conditioning factors and, in some cases there is no correspondence between the applied methodology and the postulated objectivesSpanish Ministry of Economy and Competitiveness (Research Project TRA2015-66235-R)

Tool to manage Road Safety Deficiencies and risk of highway crashes

[EN] In order to facilitate the management of the results obtained in the project “Analysis of the relationship between Road Safety Deficiencies, crashes and hazardous sections” financed by Public Works Agency of the Regional Government of Andalusia (AOPJA) and led by the research group TRYSE from University of Granada, a safety management tool has been developed. This application allows safety managers to consult some factors affecting crashes on two-lane rural highways. The main aim of that project was to analyze the influence of some road deficiencies on crashes and hazardous sections in the Complementary Road Network of Andalusia. These deficiencies were defined in a checklist and were identified by a road inspection. Decision Trees (DTs), that are a data mining technique that allows the extraction of Decision Rules (DRs), were used. DRs revealed the relationship between road deficiencies and crashes. The application allows two different analyses. A specific analysis of the Complementary Road Network of Andalusia, in which, particular safety problems can be identified, and the location of roads with those problems can be obtained. A more general analysis in which some characteristics related to road safety can be selected in order to know the combination of factors contributing to traffic crashes. Safety problems are based on data from Complementary Road Network of Andalusia but results can be extrapolated to other rural highways in Spain.López Maldonado, G.; Baena Ruíz, L.; Garach Morcillo, L.; De Oña López, J. (2016). Tool to manage Road Safety Deficiencies and risk of highway crashes. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 1553-1561. https://doi.org/10.4995/CIT2016.2015.4068OCS1553156

Influencia del gasto en construcción y mantenimiento de carreteras en la seguridad vial en el contexto europeo

El presente artículo analiza la influencia de los recursos económicos invertidos en la red viaria, tanto en construcción como en mantenimiento, sobre el número de fallecimientos producidos en la misma. Dada la multitud de factores de los que depende el tema de estudio, además de los recursos económicos invertidos, se incluye una serie de variables explicativas que tratan de reflejar características de la red viaria, aspectos socioeconómicos, meteorológicos y legislativos. Para ello, se ha construido un modelo de datos de panel para 22 países europeos y para el período comprendido entre 1998 y 2016, para la red viaria interurbana. Los resultados muestran un efecto beneficioso del gasto en mantenimiento de carreteras sobre la mortalidad. También se han hallado resultados significativos para la construcción de carreteras, la proporción de vías de gran capacidad, el PIB per cápita y el carnet por puntos.Este estudio ha sido realizado en el marco del proyecto “Inversión en carreteras y seguridad vial: un análisis internacional (INCASE)”, financiado por: FEDER/Ministerio de Ciencia, Innovación y Universidades–Agencia Estatal de Investigación/ Proyecto RTI2018-101770-B-I00, dentro del Programa Estatal de I+D+i Orientado a los Retos de la Sociedad

Using Decision Trees for comparing different consistency models

[EN] One technique used to improve highway safety from the point of view of the infrastructure is to examine the consistency of the design. Design consistency refers to if highway geometry is conformance to driver expectancy. When the consistency of the road is inadequate, the more likely it is that drivers will be startled and a crash will occur. The consistency, based on operating speed, has been calculated in Spanish two-lane rural highways. This consistency has been evaluated using a local method, to measure the consistency of each element of the road and using a global method, to measure the consistency of a segment of the road. Different models of consistency have been compared using Decision Trees (DTs). DTs are a Data Mining Techniques which can be used to solve classification problems. The results show that DTs are a suitable technique to compare consistence models and they permit to establish limits between the different models analyzed.Support from Spanish Ministry of Economy and Competitiveness (Research Project TRA2012-37823), co-funded with FEDER, is gratefully acknowledged.Griselda López wishes to express her acknowledgement to the regional ministry of Economy, Innovation and Science of the regional government of Andalusia (Spain) for their scholarship to train teachers and researchers in Deficit AreasGarach Morcillo, L.; Calvo Poyo, FJ.; López-Maldonado, G. (2014). Using Decision Trees for comparing different consistency models. Procedia - Social and Behavioral Sciences. 160:332-341. https://doi.org/10.1016/j.sbspro.2014.12.145S33234116

Influence of Wider Longitudinal Road Markings on Vehicle Speeds in Two-Lane Rural Highways

Longitudinal road markings are a valuable aid in driving guidance. An increase in their width may influence driving and, therefore, road safety. Wider road markings generate a perception of a narrowing lane, which may induct drivers to reduce speed. The present study tries to verify if an increased width of longitudinal road markings actually helps one to drive more slowly, and consequently leads to enhanced road safety. For this purpose, three curves with reduced visibility were selected and driving speed was measured with normal and modified (wider) longitudinal road markings. The results showed a speed reduction effect of around 3.1% with wide road markings. The speed-reducing effect of wide marks was greater during weekends and with more intense traffic volume, while it was slightly attenuated by night. Finally, the calculation of some standard cases on a working day, and considering average traffic volume, gave the following speed reductions during the day and at night, respectively: for light vehicles, 2.24% and 1.96%; for heavy vehicles, 2.46% and 2.15%. In view of the results obtained, it may be said that using wide road markings can help reduce vehicle speed, thereby contributing to reduced traffic accidents and making road transport more sustainable.Ministry of Economy and Competitiveness of Spain TRA2012-37823Ministry of Science, Innovation and Universities of Spain RTI2018-101770-B-I00European Union (EU

The effect of widening longitudinal road markings on driving speed perception

Road markings may influence driver behavior, and therefore road safety. An increase in the width of road markings might lead drivers to perceive lanes to be narrower than they really are, creating the illusion of traveling faster. The objective of this paper is to analyze whether wider longitudinal road markings can affect the perception of lane width and thus induce drivers to slow down. To this end, three curves with reduced visibility were selected for a field experiment. The road markings were painted wider than normal, and video recordings were made with narrow and wide markings by a camera installed in a vehicle. A total of 14 videos were shown to each of the 185 participants; then a survey was carried out to analyze in which video the participants perceived higher speed. The results showed that if the participants perceived differences in speed, the higher speed was perceived with the wide markings. This perception of higher speed increased if the participant was female, or if the participant had ever had an accident. In view of the obtained results, it can be said that the use of wider road markings could help reduce vehicle speed, thus contributing to improved road safety.Spanish Government TRA2012-37823 RTI2018-101770-B-I00European Commission(Ministry of Public Works)(Asfaltos y Construcciones ELSAN

Driving speed perception survey results

Database for the analysis of the perception of speed when one drives along curves with wider longitudinal markings than the ones established by the traffic code. To this end, video recordings of vehicles traveling along curves with normal longitudinal markings and modified ones (wider) were made. Then, a survey was carried out. The participants were shown the videos and asked in which they perceived a greater vehicle speed. This database includes the results of that survey.Spanish Ministry of Economy and Competitiveness for funding the project "Increasing the width of road markings as a tool for reducing the speed on highway sections with safety problems (MARVIVEL)", reference TRA2012-37823, and to the Ministry of Science, Innovation and Universities of Spain, for funding the project “Investment in roads and road safety: An international analysis (INCASE)”, reference RTI2018-101770-B-I00 (MCIN/AEI/10.13039/501100011033). Both projects were co-funded through FEDER