Search results for " roundabouts"
showing 6 items of 16 documents
A grid of material and immaterial laboratories for supporting the sustainability of transportation: the RESET project in Sicily
2015
Transportation is a crucial sector, to be suitably approached in order of getting human activities in more environmentally sustainable paths. In fact, in developing, as well in less developing, countries people and freights mobility are responsible of important amount of pollutant emissions and are cause of significant levels of energy consumptions. In this paper, a Sicilian regional project is presented, aiming at establishing an interconnected grid of material and immaterial laboratories. These laboratories, that are devoted at inducing more virtuous behaviors in the transportation policies, are constituted by equipment and software tools, mainly located in the region’s universities, acti…
Reducing Air Pollutants through Road Innovative Intersections
2013
Road pollutant emissions are correlated mainly to infrastructural capacity and to traffic intensity and typology. With the aim to improve road intersections performances in the last years was designed many new geometric layouts, like turbo roundabouts and flower roundabouts. The main objective of this paper is carried out a comparative analysis between conventional and innovative roundabouts in terms of CO, CO2, NO and PM2,5 vehicular emissions, evaluated by means of COPERT Software which is developed as a European tool for the calculation of emissions from the road transport sector.
Calculation of turbo- roundabouts with slip lanes
2013
A turbo roundabout is a particular type of roundabout where all lanes are bounded by traffic signs and by non-mountable curbs installed at entering and circulating lanes. Turbo roundabouts also have a very particular shape to accomplish the splitting of traffic streams and to prevent cars weaving through. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. Only in some traffic conditions, turbo roundabouts can offer higher capacities than conventional double-lanes roundabouts, so if more capacity must be guarantee a bypass lane can be added t…
Turbo-Roundabouts: a Model to Evaluate Capacity, Delays, Queues and Level of Service
2012
A turbo roundabout is a particular type of roundabout where entering and circulating lanes are bounded by traffic signs and by non-mountable curbs. The physical separation between lanes, both at entries and on the ring, helps to prevent side collisions crossing the roundabout. The main advantages of turbo roundabouts are: i) reduction in the number of potential conflict points; ii) lower speed of vehicles passing through the intersection; iii) safety conditions at the intersection due to lower risk of side-by-side accidents. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestri…
Application of a genetic algorithm in calibration of traffic microsimulation models
2017
This chapter describes the genetic algorithm-based calibration procedure for a microscopic traffic simulation model focusing on freeways and modern roundabouts. For both case studies, the genetic algorithm tool in MATLAB® was applied in order to reach the convergence between the outputs from Aimsun microscopic simulator and the observed data. The automatic interaction with Aimsun software was implemented through an original external Python script. Results showed that the genetic algorithm-based calibration procedure gave a better match to the observed data than simple manual calibration and the efficiency of the calibration efforts resulted significantly improved. At last, the calbrated mod…
Cost-benefit analysis of road safety measures
2013
Road accidents represent one of the most serious problems faced by the Ministries of Public Health in the World. In Italy for example, in the year 2007 there were almost 330, 000 injuries and 5, 131 fatalities; 230, 871 crashes in all which resulted in an estimated € 30.4 billion financial loss, corresponding to 2% of GDP. In 1999 the National Road Safety Plan (NRSP), among other things, funded the requalification of several unsafe road infrastructures at higher risk of accidents. Unlike other infrastructure investment plans, NRSP usually requires: i) specific safety analysis of crash history to identify the critical road; ii) proactive action, e.g. RSAs and RSARs; iii) before-after acciden…