The Moral Case for Intelligent Speed Adaptation

Hierarchical Bayesian modeling to evaluate the impacts of intelligent speed adaptation considering individuals’ usual speeding tendencies: A correlated random parameters approach

ROAD SAFETY: A MAJOR PUBLIC HEALTH ISSUE

On the basis of the characteristic of traffic simulation technique, which is intuitionistic, exact, agile and can be tested repetitively, this paper deal with the relation between the Intelligent Speed Adaptation (ISA) and the driving safety. Different percentage of ISA vehicles and their speed distribution were constructed to simulate the traffic flow based on Vissim. Velocities of vehicles in different percentage of ISA were recorded to evaluate traffic rates. Mean speed and standard deviation of speed decreased as percentage of ISA vehicles increased according to the simulation result. Considering accident rate is determined mostly by deviation of speed, accident rate may decrease about 27% if all vehicles adopt ISA. As a conclusion, ISA is a hopeful proactive technology.

How much benefit does Intelligent Speed Adaptation deliver?—An analysis of its potential contribution to safety and environment

As a new approach, intelligent speed adaptation (ISA) systems are being developed to provide drivers with assistance for controlling their driving speeds. In this study, ISA impacts were investigated through micro-simulation. The simulation results show that ISA has positive impacts on safety in terms of reducing speeds and speed variations. Applying ISA can harmonizing vehicle speeds between and within lanes, which results in reductions of the number of lane changes and short time-to-collision events. However, journey times could be increased because of speed decreases. This is part of the work of STARDUST, an EU project aimed at assessing the extent to which advanced driver assistance systems (ADAS) and automated vehicle guidance (AVG) systems can contribute to sustainable urban development. The main objective of this simulation study was to assess what impacts intelligent speed adaptation (ISA) have on traffic performances.

Desirability of advanced driver assistance from road safety perspective: the case of ISA

A sustainable transport system needs to focus not only on reliability and efficiency, but also on the safety aspect. Speeding problem has becoming one of the major road safety focuses around the globe (Global Road Safety Partnership, 2008; OECD/ECMT Transport Research Centre, 2006). Many researchers have shown the negative effect of speeding on road safety (Nilsson, 2004; Walz et al., 1983; OECD/ECMT Transport Research Centre, 2006). One of the speed management strategies to reduce the harmful effects of speeding is by utilizing in-vehicle technology such as intelligent speed adaptation (ISA). Several previous researches have shown the effectiveness of ISA system in reducing the speeding problem (Sundberg, 2001; Lahrmann et al., 2001; Jamson et al., 2006). This concept paper discusses the settings of a pilot study in Malaysia along with its challenges as well as recent progress on adapting a commercially available handheld GPS device as working ISA system.

Intelligent speed adaptation (ISA) has the potential to improve road traffic safety significantly. Large-scale implementation of ISA, however, is hampered by large uncertainties, such as the level of compliance (LC), reliability of the technology, unexpected costs and so on. We suggest an adaptive policymaking approach for implementing ISA. We propose five steps: (1) specify the policy problem, (2) assemble a basic policy, (3) specify the rest of the policy, (4) learn from real world experience with the basic policy and (5) adjust the implemented policy. We demonstrate, as a proof of concept, how to design a basic ISA policy and how to gain knowledge over time about the behaviour of the system in order to resolve some of the uncertainties and improve the policy. By monitoring the percentage of speeding drivers to detect changes in the LC, the policy can be adapted to unfolding events. Hence, by using the adaptive approach, policymakers can proceed with implementing ISA despite the large uncertainties.

Formal Models for Intelligent Speed Validation and Adaptation

Intelligent speed adaptation: Preliminary results of on-road study in Penang, Malaysia

An ex ante impact assessment of advanced driver assistance systems was conducted with focus on autonomous intelligent cruise control and intelligent speed adaptation. The effects of these systems on efficiency, reliability, driving comfort, and safety were addressed by microsimulation for different penetration levels and bottleneck layouts. The deployment of cruise control improves bottleneck capacity. The bottleneck reliability, however, deteriorates in most cases. No significant changes in traffic safety, expressed by the time drivers are exposed to small time-to-collision values, could be established. From the simulation experiments it appears that intelligent speed adaptation has no effect on capacity and provides no substantial contribution to bottleneck reliability. Contrary to expectations, no significant safety benefits could be established using the study’s assessment approach.

The recent Swedish Intelligent Speed Adaptation (ISA) study included a component that involved the installation of GPS-based units in hundreds of cars in three Swedish cities (Borlange, Lund and Lidkoping) and observed these vehicles for up to two years. In Borlange, the speed and location data of each vehicle were transmitted at regular intervals to a central server and stored for later analysis. This dataset contains a wealth of travel behavior information that, to date, has never been available. However, a dataset of this magnitude introduces a major need for automated processes that can glean the travel behavior details out of the trip summary and GPS point files collected for such a large scale study. This paper presents a summary of the characteristics and issues with the Borlange GPS dataset, which includes 186 personal vehicles that have at least 30 days of travel data and corresponding household socio-demographic data. (These 186 vehicles recorded 49,667 vehicle days of travel and 240,435 trips inside the study area.) The paper then presents automated methodologies for imputing trip purpose for these trips once the trip destinations are identified, as well as correcting the GPS traces and identifying missing trips (or trip ends) within these trips. Results of these automated processes for a subset of the ISA study vehicles are included.

Compared to the motorway network, rural and urban roads are very unsafe. Advanced Driver Assistance Systems can be used to increase traffic safety, thereby improving the conditions for effective deployment of the underlying network for integrated traffic management. In this study, we have identified ADA systems that are expected to have a high impact on traffic safety by coupling characteristics of accidents to the functionality of different ADA systems. Based on the results of this study, Intelligent Speed Adaptation (ISA) and Intersection Crash Avoidance systems appeared most likely to substantially improve the safety on non-motorway roads. ISA was selected for further analysis due to the likelihood of timely deployment of the system. Microscopic simulation model was used to quantify the impacts on traffic safety for an urban highway with controlled intersections near the Dutch city of Delft. Depending on the penetration level, the results of the simulation study showed that the decrease in the total number of accidents ranges from 4% to 19%.

Adapting ISA system warnings to enhance user acceptance

The long-term effect of intelligent speed adaptation on driver behaviour