Abstract
Nowadays vehicles are already able to connect to the internet and provide information to the driver. As a next step, vehicles are expected to use vehicle-to-vehicle and vehicle-to-infrastructure communication (V2X) to allow safer, more efficient and more comfortable driving. The driver, for example, will be warned against hazardous situations precociously, even if these are out of sight due to a bend or other vehicles ahead. One V2X communication technology used to enable cooperative ITS is an ad-hoc Wireless LAN network (IEEE 802.11p).
During the last years V2X communication has already proven technical feasibility. However, to prepare the deployment of cooperative ITS and evaluate interesting applications, a large scale field operational test under everyday life conditions was needed. One example application, the “Emergency Electronic Brake Light” (EEBL), warns the driver about a hard braking vehicle ahead, even if out of sight due to a curve or other traffic in-between. The potential effect of this function has been successfully validated in “Safe Intelligent Mobility – Testfield Germany” (simTD). This joint industry initiative aimed for validating the effect of cooperative ITS on traffic safety and mobility. For a period of six month 120 vehicles with more than 500 drivers had been underway on public roads around Frankfurt/Main, Germany. In total more than 1.6 million kilometres had been driven and about 30 Terra Byte of log data needed to be analysed.
Ford Research and Advanced Engineering took the lead for developing, testing and evaluating EEBL. Besides EEBL other cooperative features had been tested and validated as well, such as “Road Works Warning”, “In-vehicle Signage”, “End of Traffic Jam Warning”, and “Intersection and Cross Traffic Assistance”.
EEBL has firstly been tested in a driving simulator. In cooperation with the University of Wurzburg EEBL was under investigation by selected drivers in various scenarios. The results are promising: in dense traffic situations, when a hard braking vehicle is not visible, a positive effect on drivers’ safety could be elaborated. The time-to collision (TTC) is enlarged and the vehicle brakes even harder. As a next step EEBL has been validated as part of the driving tests, too. In order to avoid any potentially hazard the EEBL tests have been performed on an enclosed test area. Here, EEBL had been tested in various scenarios with different numbers of equipped vehicles. The positive results from the simulator study could be verified with the driving tests, too. Summarizing the results of simTD a positive effect on traffic safety and efficiency has been demonstrated.
Besides the technical evaluation simTD investigated also user behaviour and user acceptance of cooperative ITS. The majority of test drivers showed interest to use the simTD functions in their vehicle and are willing to share driving profiles anonymously.
As a result of the socio-economic analysis full penetration with simTD functions will allow avoiding up to EUR 6.5 billion in terms of economic cost of road traffic accidents. Additionally, an economic benefit of EUR 4.9 billion can be achieved through reducing congestion and avoiding pollution.
This paper outlines some of the key findings from the simTD project, in particular for EEBL.
Keywords - Connected vehicle, V2X communication, Advanced Driver Assistance Systems, Electronic Brake Light