Risk analysis in the surrounding areas of one-runway airports: A methodology to preliminary calculus of PSZs dimensions

The risk analysis of aeronautical accidents has been faced in several countries in order to plan the territory around airports. In the past, many accidents have had serious consequences in the surrounding of airports. To protect the dwellers in these zones, Sapienza University of Rome has studied a risk assessment model of air crash accident during take-off or landing. In force of an agreement with the National Aviation Authority, the major Italian airports have been analyzed. These studies have highlighted the opportunity to know the influence on the territory of the variation of the traffic volume. This knowledge can be particularly useful for forecasting the impact on the territory in a preliminary phase of the master planning activity of the airport. The influence of the traffic volume and the types of aircraft on the sizes of safety areas around airports has been studied with a computer program developed by the authors. As a result of this first analysis, a simplified approach to study the extension of the Public Safety Zones around an airport is presented. This method calculates the area and the main dimensions of PSZs for a number of representative cases of one-runway airports with more than 30000 operations per year. In Europe, there are a large number of one-runway airports and they have similar operational and traffic conditions. Therefore, the results here presented can be applied for a preliminary study to all the one-runway airports, having the same level of traffic of the airports considered in this paper

Environmental, human health and socio-economic effects of cement powders: The multicriteria analysis as decisional methodology

The attention to sustainability-related issues has grown fast in recent decades. The experience gained with these themes reveals the importance of considering this topic in the construction industry, which represents an important sector throughout the world. This work consists on conducting a multicriteria analysis of four cement powders, with the objective of calculating and analysing the environmental, human health and socio-economic effects of their production processes. The economic, technical, environmental and safety performances of the examined powders result from official, both internal and public, documents prepared by the producers. The Analytic Hierarchy Process permitted to consider several indicators (i.e., environmental, human health related and socio-economic parameters) and to conduct comprehensive and unbiased analyses which gave the best, most sustainable cement powder. As assumed in this study, the contribution of each considered parameter to the overall sustainability has a different incidence, therefore the procedure could be used to support on-going sustainability efforts under different conditions. The results also prove that it is not appropriate to regard only one parameter to identify the ‘best’ cement powder, but several impact categories should be considered and analysed if there is an interest for pursuing different, often conflicting interests

New research opportunities for roadside safety barriers improvement

Among the major topics regarding the protection of roads, restraint systems still represent a big opportunity in order to increase safety performances. When accidents happen, in fact, the infrastructure can substantially contribute to the reduction of consequences if its marginal spaces are well designed and/or effective restraint systems are installed there. Nevertheless, basic concepts and technology of road safety barriers have not significantly changed for the last two decades. The paper proposes a new approach to the study aimed to define possible enhancements of restraint safety systems performances, by using new materials and defining innovative design principles. In particular, roadside systems can be developed with regard to vehicle-barrier interaction, vehicle-oriented design (included low-mass and extremely low-mass vehicles), traffic suitability, user protection, working width reduction. In addition, thanks to sensors embedded into the barriers, it is also expected to deal with new challenges related to the guidance of automatic vehicles and I2V communication

Consistency and stability of risk indicators: The case of road infrastructures

Over the last decade, the World Road Association – PIARC and several European research projects, among which Ecoroads, have encouraged a promising reflection on risk analysis methods, acceptance criteria and safety practices applied to the road system. The goal of this research activity is the definition of best practice for safety analysis and management to be applied to network TERN (Trans European Road Network). Quantitative Risk Analysis (QRA) provides much information on safety management. Nevertheless, the potential fragility of the method, stochastic uncertainties (both parameters and models), and ethical aspect of criteria must be adequately analyzed. This paper focuses on all these aspects, assessing the reliability of QRA due to modeling errors and statistical errors, and assessing the statistical consistency of Risk Indicators of QRA

Comparative life cycle assessment of lighting systems and road pavements in an Italian twin- tube road tunnel

This work calculates and discusses the Life Cycle Assessment (LCA) of four scenarios composed of two types of road pavements and two types of lighting systems to be built in an Italian twin-tube road tunnel. A 20-year time horizon is adopted to assess the burdens of construction and maintenance of both flexible and rigid pavements and high-pressure sodium (HPS) and lightemitting diode (LED) lamps, traffic, and switching on of lamps. All considered scenarios are comparable with each other in terms of technical performances, but significantly differ regarding their environmental consequences. The geometrical and technical characteristics of the examined scenarios comply with current Italian standards for highways. In all the examined cases, LCA is carried out according to the European standard, EN 15804, and includes 19 impact categories (IC). The analysis demonstrates that the use of more reflecting surface pavement materials (i.e., concrete vs. asphalt) and more performing lighting systems (i.e., LED vs. HPS) can effectively mitigate the deleterious burdens related to road construction, maintenance, and use. For most of the examined ICs, the most environment-friendly scenario has LED lamps and concrete pavement

Technical and Economic Criteria to Select Pavement Surfaces of Port Handling Plants

A port is an intermodal system in which many logistics activities requiring properly constructed areas occur. The large extension of these areas poses a major problem in choosing materials with technical and economic implications. Choice and design of pavements are directly related to the port handling systems and procedures for the disposal of the cargo units. The paper presents the design and verification procedures for three equivalent pavements for a handling pavement in an Italian medium-sized port trafficked by reach stackers moving containers. An asphalt pavement, a concrete pavement, and a concrete block pavement have been considered during the 20-year service life. Empirical and analytical methods have been adopted to design and verify the pavements. The structures have been examined in terms of economic concerns during the overall service life, considering both construction and maintenance costs, in order to determine the most cost-effective option. The results demonstrate the inappropriateness of asphalt pavement, in the examined case, from a construction costs point of view. Furthermore, the overall discounted costs show an inversion of convenience between block concrete pavement and cast in situ concrete: the latter is the cheaper solution. The proposed methodology can balance often conflicting objectives in matters of durability and funds management, providing answers to a complex topic

The public safety zones around small and medium airports

Proper planning around airports safeguards the surrounding territory from risks of air accidents. Many countries have defined Public Safety Zones (PSZs) beyond the runway thresholds as a result of targeted risk assessment methods. Therefore, national aviation Authorities could limit building construction and industrial development in order to contain the risk for dwellers to be involved in aircraft accidents. The number of people who live, work or congregate in these areas should be limited. The procedure to set Public Safety Zones is based on advanced technical analyses for major infrastructures. For smaller airports, simplified schemes are used, but, sometimes, they are not as effective when considering the actual safety conditions. This article aims to identify the shape and size of the Public Safety Zones for small and medium one-runway airports. The influence of the volume and mix of traffic on the PSZ geometry has been evaluated using the program named SARA (Sapienza Airport Risk Analysis); the results are correlated with the current Risk Plans generally adopted in Italy. According to the air traffic, the Risk Plans are characterized by a dynamic definition and fit the results obtained from risk assessment

Geometrical and functional criteria as a methodological approach to implement a new cycle path in an existing Urban Road Network: A Case study in Rome

Most road accidents occur in urban areas and notably at urban intersections, where cyclists and motorcyclists are the most vulnerable. In the last few years, cycling mobility has been growing; therefore, bike infrastructures should be designed to encourage this type of mobility and reduce motorized and/or private transport. The paper presents a study to implement a new cycle path in the existing cycle and road network in Rome, Italy. The geometric design of the new path complies with Italian standards regarding the technical characteristics of bicycle paths, while the Highway Capacity Manual has been considered for the traffic analysis. In particular, a before-after approach has been adopted to examine and compare the traffic flow at more complex and congested intersections where the cycle path will pass. Trams, buses, cars, bikes and pedestrians were the traffic components considered in each analysis. The software package PTV VISSIM 8 allowed the simulations of traffic flows at traffic-light intersections; an original linear process has been proposed to model dynamic intelligent traffic controls, which are not admitted by the software used. The traffic analysis allowed the identification of the best option for each of the five examined intersections. Particularly, the maximum queue length value and the total number of passed vehicles have been considered in order to optimize the transport planning process. The results of this study highlight the importance of providing engineered solutions when a cycle path is implemented in a complex road network, in order to avoid negative impacts on the citizens and maximize the expected advantages

Concrete block pavements in urban and local roads: Analysis of stress-strain condition and proposal for a catalogue

Although the construction of block pavements has grown fast in the last decades, there is still a need for simple tools that could be applied to design them. This paper analyzed and verified concrete block pavements for urban and local roads composed of rectangular concrete pavers with plane side surfaces (no interlocking effect). The examined blocks were laid on a bedding sand layer, a cement treated base layer and a granular unbound foundation layer. The commercial finite element (FE) software ANSYS® was used to calculate the response of the pavement when subjected to different loading, construction configurations. Three wheel positions, five blocks patterns, three bedding sand thicknesses and joints gaps have been considered to evaluate stress-strain condition on pavement materials. Fatigue and rutting verification was performed respectively for bound and unbound pavement materials using analytical curves available in the literature. At the end of this study, a proposal for a catalogue is presented. It has nine pavement sets, because it takes into account three values of subgrade capacity (30, 90, and 150 MPa of resilient modulus) and three levels of traffic (400,000, 1,500,000, and 4,000,000 passages of commercial vehicles during the service life). The obtained results provide an inexpensive procedure for the preliminary design of concrete block pavements. Keywords: Block pavement, Finite element model, Concrete pavers, Local roads, Urban road

Analytical method for calculating sustainable airport capacity

Capacity is the attitude of an airport to manage a number of operations in a given time interval within a fixed maximum delay (and under given safety conditions). Capacity studies are commonly carried out on five levels of analysis according to the required detail in order to identify the best option that balances economic, logistic and safety issues. This study focuses on level 3 (i.e., analytical methods) developing a calculation model to assess the runway capacity. The model was calibrated by comparing the outputs of different airport configurations with those provided by the circular of the Federal Aviation Administration Airport Capacity and Delay. The model was well calibrated with maximum differences in the analyzed configurations that stood at 1 or 2 movements/hour. The runway capacity of an international airport was calculated and compared to that of the entire airside, assessed through fast time simulation, in a previous study. The analytical model provides runway capacity slightly higher than that of the entire air system, as it cannot evaluate all the critical issues present in the airport that reduce its maximum theoretical capacity. Therefore, depending on the degree of detail required, you can use the developed model or the simulation software; the use of the latter is possible when the airside infrastructure does not adequately support the runway system or in cases of advanced design level