Demetrio Carmine Festa

Comparing Safety Performance Measures Obtained from Video Capture Data

Safety performance is evaluated by using measures obtained experimentally from a videotaping of traffic operations at an urban roundabout situated in Cosenza, Italy. Five different expressions of safety performance from the perspective of “rear-end” vehicle interactions include maximum deceleration rate to avoid a crash (DRAC), time-to-collision (TTC), proportion of stopping distance (PSD), time integrated time-to-collision (TIT), and crash potential index (CPI). Differences in safety performance are discussed with respect to the type of measure, traffic conditions, and variations in roundabout geometry. The results of this analysis suggest that safety performance is highly sensitive to the way it is measured; different measures can highlight different locations or geometric features of the roundabout as posing potential safety problems. This study underscores the usefulness of safety performance measures for providing meaningful experimental indicators of potential safety problems at roundabouts and how ...

Using Smartphones as a Tool to Capture Road Traffic Attributes

Road network management under critical conditions is achievable by adopting technologies that trace vehicles and capture unsafety events to provide users with real time traffic information. Most common approaches used to acquire vehicle tracking data are based on video image processing algorithms and satellite navigation systems. However, many studies are increasingly focused on the emerging smartphone technologies for tracking vehicles. The aim of this study is to present a procedure for acquiring vehicle tracking data from smartphone sensors, supporting managers of transportation systems to take effective decisions on their networks, especially in conjunction with special events and/or critical road safety issues.

Experimental tour-based travel demand models

Abstract In this paper some experimental sequential models for the simulation of trip-chains are presented; the models have been calibrated on the basis of a survey made in a medium-sized town. This work is part of a research, effected by the Department of Regional Planning of the University of Calabria, to forecast travel demand and to analyze travel behavior of the transport system users (Festa et al., 2000). The travel choices of individuals have been reproduced simulating the decisional process in sequential steps, by models based on the random utility theory. The tour generation models, proposed by Festa et al. (2001), have been once again calibrated introducing a new set of variables in the systematic utility function of the alternatives of choice. Some models for the travel type choice simulation are also presented; the models have a Binomial Logit functional structure, with trip-tour and trip-chain as choice alternatives.

EcoSmart: An Application for Smartphones for Monitoring Driving Economy

nstantaneous consumption models are designed to provide an accurate description of fuel consumption by relating the instantaneous rate of consumption with the vehicle acceleration, speed and the engine dynamics. In principle, instantaneous consumption models allow users to calculate the fuel consumption for any profile of vehicle operation. Some kind of models that take into account only driving dynamics can be used to describe the variability of consumption. The procedure used by this type of models is to establish reference matrices (related to specific time intervals) that for each combination of speed and acceleration determine the rate of fuel consumption. This paper Describes the design of a mobile application for the estimation of consumption, and user behavior, that applies models of instantaneous consumption. A preliminary experimental survey has been the carried out to obtain a large data base related to the acquisition of cinematic and engine parameters to allow the development of the mobile application. The experimental acquisition of parameters was accomplished in dynamic driving, connecting the OBDII port to different models of vehicles. With this procedure, reference matrices of fuel consumption for each specific class of emission (as required by ECE 15.03 - Directive 78/665/EEC and ECE 15.04 - Directive 83/351/EEC) have been obtained. The mobile phone application, after receiving as input the vehicle specifications provided by the user, can associate the specified matrix of consumption to the cinematic parameters (instant speed and acceleration obtained by GPS measures) and by using each pair of speed and acceleration can give an estimate of consumption values. At the end of the trip the user can take view of all device information on consumption also by geo-displaying the information on a map (showing the path and the related point by point consumptions). The output of the system, that can also provide information related to the dynamic behaviour and energy management in the user guide style, have been confronted with real consumption data. The advantage of the application is to estimate fuel consumption and driving style, from just GPS data, without connecting the phone to OBDII port.

EcoSmart: A Survey and Sector Analysis of Mobile Phone Application Market for Fuel Consumption Reduction

The spread of Smartphones and Tablets has led to the birth and the development of a new business: mobile applications on smartphones. Mobile telephonys continuous growth implies a large number of users that can access all applications of online stores. Mobile business is evolving continuously and offers applications that grant many different innovative services and at the same time mobile business offers many opportunities of development for companies and corporations because participating this new sector is becoming more and more required to improve performances and competitiveness. The purpose of this paper is a quantitative analysis of the smartphone application market through a survey of users desires and an analysis of different mobile application features and business models. The results of the survey provide a full representation of the mobile market potential, with a focus on the applications that work on fuel consumption reduction and road safety. In this framework an evaluation of the presented application EcoSmart is carried out. The application estimates users fuel consumption and returns conclusions about his driving style (with focus on fuel consumption). The user can also review offline his paths and the geo-localised driving style data thanks to the Smartphones GPS. The EcoSmart application replaces the OBD device and the consumption data, that can be obtained from the car engine, approximating fuel consumption just based on the dynamic of vehicle motion that is evaluated on GPS data. This procedure is simple and innovative. This study provides a demand survey for this kind of services and a sector analysis. The survey has been carried out using traditional market research methods, with a qualitative approach that is used to understand users habits of purchase and users desires. The second one was realised investigating the applications which are similar to EcoSmart on the Apples Appstore and the Google Play Store, analysing their features and how they can be distributed to the users.

Traffic Delays Estimation in Two-lane Highway Reconstruction

Abstract An increasingly important issue, as congestion levels increase more and more, is that freeways become subject to rebuilding and restructuring when traffic cannot be re-routed. It has already been asserted that traffic simulation provides a better approach to the analysis of freeway reconstruction than the traditional Highway Capacity Manual. In fact the users’ delay on freeway under reconstruction, when traffic flow is under capacity, cannot be evaluated by the standard HCM procedures. The impacts on existing traffic patterns are significant: the costs of delay and safety suffered by users even for low flows requires to take adequate management actions. From the point of view of direct reconstruction costs, every attempt to reduce user cost brings an increase in the direct costs of rebuilding. So there is a clear trade-off between reducing direct costs and mitigating the costs to travellers and economic activities. The object of this paper is to allow the evaluation of the delay that is suffered by the users of two-lane freeways when only one lane is available. The delays for different flow levels and different lengths of the reconstruction area are evaluated with the use of a tailored new developed microscopic traffic simulation model.

Co-operative ITS: ESD a Smartphone Based System for Sustainability and Transportation Safety

Abstract Co-operative Intelligent Transportation Systems (C-ITS) are emerging rapidly due to recent development in Global Navigation Satellite System GNSS systems and mobile internet. The main goal of these systems is to improve traffic conditions and safety level on the road networks. With the rapid growth of smartphone technologies and mobile internet, C-ITS based on smartphone may contribute increasingly in vehicle data collection and in traffic safety and sustainability issues. This paper, extending previous research results, explores the possibilities of using smartphone applications coupled with a central server GIS (Geographic Information System) web system to contribute to traffic safety and to reduce fuel consumption. The idea of a co-operative system in which GPS (Global Positioning System) enabled smartphones are capable to acquire individual vehicles kinematics is extended to take into account both safety and fuel consumption issues. Information in the system is shared on a web server for promoting more sustainable and safe driving styles. The co-operative system allows drivers to examine information about their individual driving style and consumptions allowing a better use of the road. Road operators can use the system to find critical points on the network and to promote traffic safety.

New methodology for the identification of road surface anomalies

This article show a methodology for the identification of road anomalies through the coupled measurements of vertical acceleration and sound pressure levels. The innovative solution of this methodology lays in the possibility to evaluate road anomalies by using the time derivative of acceleration and sound pressure. Furthermore, this methodology has been developed and validated using a commercially available instrumentation possessed by most drivers, such as, smartphones and tablets. The current smartphone devices, in fact, are equipped with GPS, gyroscope and microphone that allow to simultaneously record data relating to geolocation, acceleration and sound pressure. The widespread distribution of this equipment could allow local administration to acquire a large number of surveys carried out by normal drivers and build a large Data Base on road anomalies representative of a whole network of infrastructures with a very small cost. Finally, the application of the methodology overturns current monitoring policies of road infrastructure that can be carried out only by the management staff by crowdsourcing the DB system with continuous real time updates brought by normal road users.

A New Simulation Model Of Fuel Consumption And Pollutant Emissions In Urban Traffic

The paper presents a model for fuel consumption and pollutant emissions that is based on: average traffic speed so it can be coupled with macro traffic simulators; its range of validity (1-30 km/h) is well suited for urban congested traffic; and it reproduces consumption and emissions in presence of accelerations, decelerations, stop and go phenomena, typical of urban traffic. Fuel consumption and pollutant emissions have been computed second by second for each journey, and statistical relationships between consumption/emissions rates and average speed, observed in the test runs, have been derived by the least squares method.

Comfort Index CI(bus): A methodology to measure the comfort on board.

Abstract The presented work deals with the important topic of assessing the quality of public transport services. This research specifically addresses the performance of the service in terms of comfort. In particular, the study focuses on the definition of a comfort index (CI) that takes into account two dimensions (noise and vibration) measured on board the buses studied, both during motion and on a stationary vehicle. The methodology interprets how users perceive the comfort on board the public transport considered, with numerical data coming from high-precision measuring instruments. This methodology represents a further element of synthesis in the complex quantification of perceptions by an individual, precisely because of the extreme subjectivity of judgment.