The Computer System Architecture of our first real-time real-world experiment of adaptive traffic signals with "connected" vehicles

Abstract Connected vehicles can transmit real-time information to traffic control management systems. Despite the recent technical advances of telecommunication networks and mobile computing there have been no real-time adaptive traffic signal control experiments with connected vehicles. Most of the research in this field has been carried out only with simulations. In this work we present the computer system that was adopted to regulate traffic signals in real-time with "smartphone-connected" vehicles as the only source of information. We introduce the description of the computer system architecture that was deployed in an experiment of a Floating Car Data (FCD)-based adaptive traffic signal in which a traffic signal has been regulated in real-time with 100% "smartphone-connected" vehicles. The description of the system based on commonly-used technologies could help others to develop and deploy new traffic signal management systems in new "connected" intersections

The use of a Blockchain-based System in Traffic Operations to promote Cooperation among Connected Vehicles

Abstract This paper intends to present some ideas for the implementation of cooperative ITS systems based on the Blockchain Technology (BT) concept. Blockchain technology has been recently introduced and, in this paper, we discuss a system that is based on a dedicated blockchain, able to involve both drivers and city administrations in the adoption of promising and innovative technologies that will create cooperation among connected vehicles. The proposed blockchain-based system can allow city administrators to reward drivers when they are willing to share travel data. The system manages in a special way the creation of new coins which are assigned to drivers and institutions participating actively in the system. Moreover, the system allows keeping a complete track of all transactions and interactions between drivers and city management on a completely open and shared platform. The main idea is to combine connected vehicles with BT to promote Cooperative ITS use and a better use of infrastructures

A Review of the use of traffic simulation for the evaluation of traffic safety levels: can we use simulation to predict crashes?

Abstract This paper presents a literature review on the application of traffic simulation for the evaluation of traffic safety levels. The main aim is to identify, through the implementation of a multi-step methodology current research-trends, main gaps in the literature and possible future challenges. First, a bibliometric analysis is carried out to obtain a broad overview of the topic of interest. Subsequently, the most influential contributions are analysed in-depth, with specific attention to specific issues

A review of traffic signal control methods and experiments based on Floating Car Data (FCD)

Abstract This paper intends to give a short review of the state of the art on the use of floating car data concerning the management of traffic flow at signalized intersections. New technologies such as connected and autonomous vehicles and Co-operative Intelligent Transportation Systems (C-ITS) are going to change the future of traffic control and management. Traffic signal control systems can be reorganized by using Floating Car Data (FCD), yet the concept of floating car data (FCD) has been mainly studied to gain traffic information and/or signal information. Only recent works have been focalizing on the potential application of FCD for traffic signal real-time control. This paper aims to evidence the most important concepts that can be extracted from the literature on this important topic

Validation of Simulated Safety Indicators with Traffic Crash Data

The purpose of this document is to validate a new methodology useful for the estimation of road accidents resulting from possible driver distractions. This was possible through a statistical comparison made between real accident data between 2016 and 2018 in the city of Santander (Spain) and simulated data resulting from the application of the methodology on two areas of study. The methodology allows us to evaluate possible collisions starting from the knowledge of vehicular trajectories extrapolated from microsimulation. Studies show that there are good correlations between the real data and the simulated data. The results obtained show that the proposed methodology can be considered reliable and, therefore, it could be of fundamental importance for designers, since it would simplify the choice between different possible intervention scenarios, determining which is the least risky in terms of road safety

New formulations of the stochastic user equilibrium with logit route choice as an extension of the deterministic model

This paper addresses the stochastic user equilibrium (SUE) in the case where the route choice is the multinomial logit model (MNL). Our main finding is that MNL SUE can be formulated and solved as an immediate extension of the deterministic user equilibrium (DUE) through a particular application of Wardrop’s first principle. The latter states, in general, that at equilibrium, the cost of all used routes is equal and not higher than those of unused routes. The extension is achieved by applying this statement to the “perceived cost” of a choice alternative, which is defined here as its generalized cost plus the logarithm of its choice probability multiplied by the logit parameter. Thus, substituting in DUE models the generalized costs with the perceived costs allows to easily adapt to MNL SUE the existing formulations and algorithms for DUE, as well as to manage a smooth transition of the route choice model from stochastic to deterministic by reducing the logit parameter down to zero. Particular consideration is devoted to the interpretation of the numerical solution as a restricted logit model, where only sufficiently good alternatives receive a positive probability. A family of MNL SUE models is then presented ranging from nonlinear optimization to variational inequalities and fixed-point problems, with both explicit and implicit path enumeration. A range of numerical tests is presented with the aim of assessing the continuity of the model results for decreasing logit parameter and proving the applicability of the proposed approach to real size networks, with particular emphasis on the performance and convergence of the methods