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

quantitative risk assessment of temporary hazards and maintenance worksites in the airport safety areas a case study

Abstract Airports are complex environments where the operational conditions are subjected to different risks, both due to the intrinsic nature of the manoeuvres themselves and to the external factors, as for human actions or environmental causes. An important risk factor is the presence of temporary hazards on the runway or taxiway safety area, including work in progress related to maintenance or construction operations. Both ICAO (International Civil Aviation Organization) and FAA (Federal Aviation Administration) defined their own approach on this topic. The FAA, in the Advisory Circular "Operational Safety on Airports During Construction", states the impossibility of any construction activities within the safety area when the runway is active, while the ICAO, in the Doc 9137 "Airport Service Manual" Part 6, states specific operational restrictions for the airport which allow the presence of temporary hazard in the safety area. This paper analyses the impact of temporary hazards (for example worksites) in the safety areas, according to ICAO requirements, by using a performance approach. The method has been applied to an international airport, using the software RSARA e LRSARA, provided by ACRP (The Airport Cooperative Research Program), in order to calculate the expected risk level within the safety area. This method provides a rapid and practical evaluation of risk level, according to the ICAO Safety Management System approach, in order to optimize the maintenance operation and construction in the safety area, minimizing the closing time of the runway. The main aim of this study is to verify if, under temporary restrictive operational condition (such as the limitation on available runway length and on traffic mix and weather conditions) related to the temporary hazard presence, it is possible to guarantee sufficient safety level, without occurring in runway closures. From the analysis arose that the first factor that affects the risk level for a runway is the temporary hazard dimension: while the environmental conditions (crosswind and pavement conditions) have a minor effect

"City Sensing", Nuove tecnologie e dimensione sociale dell'informazione città territorio e ambiente

Nuovo concetto di spazio urbano, basato sul concetto di Smart City, reso possibile dal pervasivo impiego di tecnologie ICT