Research and Doctoral Thesis Project

In September 2002 I joined the research group of Prof. Dirk Helbing as a Doctoral Candidate. I am generally interested in studying and understanding the collective vehicle traffic dynamics of freeways which show a broad and amazing variety of instabilities and phase transitions (probably better known as traffic jams).

Research Field

In my work I basically focus on the modeling and simulation of traffic flow using microscopic traffic models. These car-following models describe the motion of each individual vehicle whose acceleration only depends on the vehicle ahead. On this topic I work closely together with Dr. Martin Treiber. We mainly use the Intelligent Driver Model (IDM) as basis for our freeway traffic simulations. For an interactive demonstration of the IDM and further details, see www.traffic-simulation.de. Specifically, I work on improving the lane-change behavior of the "driver-agents" for more realistic multi-lane simulations. To deal with the short comings of car-following models, we recently formulated a "Human-Driver" Model (HDM) which additionally takes specific human aspects into account such as spatial and temporal multi-anticipation, finite reaction times, finite estimation capabilities and finite attention spans.

Doctoral Thesis Project

Recently so-called adaptive cruise control (ACC) systems have hit the market for premium class vehicles. See for example the account about Volkswagen Phaeton TRW Adaptive Cruise Control. ACC systems are designed to detect and to track the vehicle ahead for measuring the actual distance, speed and speed differences. This input data allows the system to calculate the needed acceleration or deceleration to maintain a selected timegap or to prevent a rear-end collision. An ongoing research effort is to expand the applicability of ACC systems to stop-and-go or even city traffic. Besides safety concerns, the interesting question from a physicist's as well as engineer's point of view is: What will be the impact of future ACC on the traffic dynamics? Is it possible to design algorithms to improve the capacity and stability of the overall system?

To deal with this question for my dissertation, I develop and build appropriate simulation tools for studying the impact on the collective dynamics. Furthermore we model and simulate control strategies for potential ACC devices focusing on the improvement in stability and capacity of the overall traffic system. See also the articles in The Economist (July, 1st 2004), in the Financial Times Deutschland, November 27, 2006, or in the PhysicsWeb, January 20, 2006.

My work is partly funded by Volkswagen. We are working on this topic in the context of the German research initiative INVENT for intelligent traffic and user-friendly technology.