Mobility & Sustainability.

Roadworks = traffic congestion

Traffic congestion is part of everyday life in Germany. And alongside accidents, roadworks are one of the main causes. Unfortunately, these look set to become ever more frequent in the future. One reason is the increasing traffic on the roads. The above-average rise in heavy goods vehicles has also resulted in increased wear on the roads. The age of the road infrastructure and insufficient maintenance work means that the number of roadwork sites looks set to increase still further in years to come. The volume of traffic can no longer be accommodated. The result is increased traffic congestion.

The problems caused by roadworks are escalated by lack of information and driving errors with regard to distance or braking, reducing capacity on the roads even more. This means that some traffic congestion caused by roadworks could be avoided. But what is the best way to drive and how can the driver know what action to take? Our research project is working to provide an answer to this question. Although construction sites will continue to be a part of daily life way into the future, we can help guide drivers as effectively as possible through the roadwork site.

Guiding drivers and vehicles through roadwork sites
The goal of the Volkswagen roadworks pilot is to ensure optimal driving behaviour before, during and after encountering a roadwork site. Simulations in the preceding project "invent" have already proven that optimal driving behaviour adapted to the specific traffic situation helps to reduce congestion on the roads and stabilize the traffic flow. Travel times, fuel consumption and emissions can be reduced. Hazardous situations are minimized.

The roadwork pilot is based on modern communication system technology and a convenient automatic distance control system (ADC). ADC systems are already in use on the road in a large number of vehicles and will be launched in the high-volume segment soon. Current systems available on the market only take the next vehicle on the road into account and not the traffic situation as a whole. For example, these systems would provide relatively little information on a roadwork site just three kilometres away. Other vehicles currently passing the roadwork site, however, are all too aware of the situation and are faced with reduced number of lanes, lane diversions, maximum speed restrictions, volume of traffic etc. In the research project, this traffic data is evaluated and passed on to the vehicle via car-to-car communication and intelligent road side unit technology. The vehicle knows what lies ahead and shows the "traffic horizon" to the driver on the display.

The roadworks pilot also makes driving recommendations or controls the distance and speed automatically. Depending on the traffic situation, the driver is instructed to approach the roadworks with caution, directed passed the affected area without manoeuvring between lanes, and told to speed up immediately when the roadwork site has been left behind - an advantage not offered by current systems available on the market. The traffic flow remains stable and congestion is avoided.

The roadworks pilot in the "AKTIV" research initiative
Volkswagen demonstrated the latest status at the "AKTIV half-time presentation" in Bergisch Gladbach on 25 June, 2008. The information on the "traffic horizon" derived from the exchange of driving experiences plays a key role in this traffic-optimized ADC system. The roadworks pilot is part of the project Adaptive driving. Over the next 2 years of the "AKTIV" project, we will work on refining and testing our roadworks pilot.

The German research initiative "Adaptive und Kooperative Technologien für den Intelligenten Verkehr" (Adaptive and Cooperative Technology for Intelligent Driving) aims to help achieve safe and flowing traffic on the roads. The initiative was launched on 1 September 2006 and is subsidized by the Federal Ministry for Economics and Technology. 28 partners from a wide range of sectors (mainly automotive, electronics, telecommunication, software and science) will carry out research until 2010 on new traffic solutions for driver assistance systems, information technology and improved traffic management systems. The central goal of this research is to create and test prototypes in real-life conditions. The mid-term goal is to create marketable innovations.