Berlin 2005 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

AKSOE: Physik sozio-ökonomischer Systeme

AKSOE 5: Traffic Dynamics, Urban and Regional Systems I

AKSOE 5.2: Talk

Saturday, March 5, 2005, 11:00–11:30, TU P-N203

Modelling Traffic Flow Fluctuations — •Peter Wagner — Institute of Transport Research, German Aerospace Centre, Rutherfordstrasse 2, 12489 Berlin

The analysis of time headway distributions of traffic flow yield an interesting result: when viewed as a function of speed, the headway distribution undergo a transition from a Poissonian dominated regime (for large speeds) to a power-law regime (for intermediate speeds in the range 10 ≤ v ≤ 30 m/s). The power-law distribution can be modelled by a simple stochastic process (stochastic differential equation) that act on the preferred headway of an individual driver.

Additionally, more detailed empirical results will be presented related to the so called slow-to-start mechanism identified for models as one of the major reasons for jam stability.

Finally, the comparison of German and US-American data-sets demonstrates similarities, as well as differences on the level of the time headway distributions.

By inserting this mechanism into microscopic traffic flow models, the models become more realistic in term of their fluctuation structure, which so far has been difficult to model. This is different from the usually fluctuation mechanism used in microscopic modelling, where the noise is acting as additive noise on the acceleration directly.