Abstract
Enhanced vehicle flow and safety, reduction and eventually elimination of traffic congestion have been attractive issues for the past two decades in the Intelligent Transportation Systems (ITS) domain. Several Advanced Driver Assistance Systems (ADAS) intended to lower down the driver workload, reduce congestion and improve safety, have been developed during this period and introduced on the market. Adaptive Cruise Control (ACC) is one of the first systems that lead towards enhanced traffic flow and safety, but it is limited on higher speeds. For low speeds a Stop and Go system has been introduced as an upgrade of ACC.
In order to achieve interoperability and harmonization several ITS standards have been developed. Even though they are regularly adopted to the technical progress to take into account the latest engine technologies, there is still a significant room for their further elaboration and evaluation of the possibilities for implementation in real urban environment (especially in the WBC region), and, if possible, proposing their further improvement.
Based on the standard ISO 22178 Low speed following systems, a research that should reveal answers to some of the problems and challenges lied down in this paper has been designed. The research is focused on urban traffic environment. Due to increased driver workload, inattention, weather and several side activities like SMS, CD and radio change, site seeing etc. vehicles movement through urban intersections gets wavy effect. In these conditions, intensive acceleration and deceleration are imminent and lead towards decreased driver concentration, reduced safety and increased fuel consumption and emission. This problem imposes the meaning of harmonized vehicle start and flow through intersections without inappropriate acceleration and deceleration and its impact on the traffic flow, safety, fuel consumption and emission.
Although the introduction of ITS standards and researches conducted in the subject field are expected to have contribution in reduction of traffic congestion and enhanced safety, there is a space for further contribution especially in term of implementation in regions, like WBC region, with not optimized urban traffic solutions and various and often old vehicle fleet.
So far, in this research, the state of the art concerning ACC and all variations and modifications of the system: control algorithms, controller designs, following models and strategies, combinations with other Driver Assistance Systems, upgrades to Cooperative Adaptive Cruise Control and Stop and Go systems, has been reviewed and analyzed. An initial model of several urban intersections using Matlab has been developed. Using this model, preliminary qualitative and quantitative results concerning traffic flow, time of travel through urban intersections, vehicle speed and acceleration/deceleration over time have been obtained. The model gives qualitative results concerning fuel consumption and emission.
Besides the subject explanation, this paper contains research approach, results already achieved and description of further research activities.
Keywords: Intelligent Transportation Systems (ITS), Adaptive Cruise Control (ACC) system, Stop and Go (SG) system, traffic flow, traffic simulator