Student Researcher: B. Zielke

Faculty Advisor: R.L. Bertini

ABSTRACT: The objective of this paper is to conduct a country specific analysis of freeway traffic oscillations. Toward this end, loop detector data from sites in the United States, Germany and the United Kingdom was analyzed. By using a method applied in previous work, traffic oscillations were identified in all three countries. Calculation of the cross-correlation coefficient reveals that they travel upstream at speeds of about 19-20 km/h at the site in the US, 16 km/h at the German site and 14 km/h on the UK freeway. Similar magnitudes were found in the literature verifying the hypothesis that they propagate faster in the US than in Germany. Furthermore, an oscillation frequency was identified by calculation of the data's autocorrelation. However, since the oscillation frequency is likely to be site specific, conclusions regarding general differences between the frequencies measured in different countries cannot yet be made. For the sites analyzed, it was found that oscillations appear every 8-12 min on the M4 (UK site), 10-30 minutes on the A9 (German site) and every 3-6 minutes on OR 217 (US site). Even though the magnitudes of the latter two countries are supported by the literature, further empirical research on several different sites should be pursued in order to draw final conclusions.

PRODUCTS:

conferenceproceedings Zielke, B., Bertini, R.L., and Treiber, M., "Empirical Measurement of Freeway Oscillation Characteristics: An International Comparison." Proceedings of the 87th Annual Meeting of the Transportation Research Board, Washington, D.C., 2008.

thesis Zielke, B., "Identification of Country Specific Characteristics of Oscillating Congested Traffic." M.S. Thesis, Technical University of Darmstadt, Germany, 2007.