Jinan Piao

Advanced driver assistance systems from autonomous to cooperative approach

Abstract Advanced Driver Assistance Systems (ADAS) have been one of the most active areas of ITS studies in the last two decades. ADAS aim to support drivers by either providing warning to reduce risk exposures, or automating some of the control tasks to relieve a driver from manual control of a vehicle. ADAS functions can be achieved through an autonomous approach with all instrumentation and intelligence on board the vehicle, or through a cooperative approach, where assistance is provided from roadways and/or from other vehicles. In this article, recent research and developments of longitudinal control assistance systems are reviewed including adaptive cruise control, forward collision warning and avoidance, and platooning assistants. The review focuses on comparing between autonomous systems and cooperative systems in terms of technologies used, system impacts and implementation. The main objective is to achieve common understanding on ADAS functional potentials and limitations and to identify research needs for further studies.

Low speed car following behaviour from floating vehicle data

In this paper, an analysis of driver behaviour is reported focusing on car following separation at low speed traffic conditions. The data used for this analysis was collected using an instrumented vehicle in three European cities: Oslo (Norway), Paris (France) and Southampton (UK). The data collection covered a wide range of traffic conditions on urban motorways, urban arterial roads and urban streets. Time gaps and distance gaps in low speed traffic conditions were investigated and were compared with those in high speed traffic conditions. This research 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 results obtained will be fed into simulation models in the next stage of the project, to assess the impacts of selected ADAS systems in the urban applications.

Safety Impacts of Variable Speed Limits - A Simulation Study

Variable speed limits have great potential for smoothing traffic and increasing traffic safety. In this study, safety impacts of variable speed limits applications on motorways have been assessed by using microscopic simulation. The main factors considered include range of speed limits, penetration rates, and enforcement levels. The study results show that application of variable speed limits on motorways can significantly reduce speed differences between and within lanes and number of small headways, an indication of safety benefits to drivers. This is part of European COOPERS project which aims to develop cooperative vehicle-infrastructure systems for increasing road safety.

An assessment of user acceptance of intelligent speed adaptation systems

As a new approach, intelligent speed adaptation (ISA) systems are being developed to help drivers to avoid speeding. In this study, driver acceptance of ISA was assessed based on questionnaire results in three European cities. The following questions were addressed in this study: (1) Do drivers like ISA systems? (2) Are drivers willing to pay for the ISA system? (3) What types of roadways driver like to use ISA systems? 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.

Vehicle positioning for improving road safety

Abstract Vehicle positioning is a key requirement for many safety applications. Active safety systems require precise vehicle positioning in order to assess the safety threats accurately, especially for those systems which are developed for warning/intervention in safety critical situations. When warning drivers of a local hazard (e.g. an accident site), accurate vehicle location information is important for warning the right driver groups at the right time. Global positioning system and digital maps have become major tools for vehicle positioning providing not only vehicle location information but also geometry preview of the road being used. Advances in wireless communication have made it possible for a vehicle to share its location information with other vehicles and traffic operation centres which greatly increases the opportunities to apply vehicle positioning technologies for improving road safety. This paper presents a state‐of‐the‐art review of vehicle positioning requirements for safety applications and vehicle positioning technologies. The paper also examines key issues relating to current and potential future applications of vehicle positioning technologies for improving road safety.

An assessment of ISA impacts through micro-simulation

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.

NETWORK EFFECTS OF VMS DURATION

In this paper, the authors describe results obtained from modeling the effects of a number of traffic incidents and scenarios in which variable message signs (VMS) were used to deliver traffic information to drivers. Results show that the benefits of on-line VMS messages varied significantly with the duration of the VMS, particularly in situations with varying incident severity and duration.