Summary
Insight into traffic flow characteristics is often gained using local measurements. To determine macroscopic flow characteristics, time aggregation of microscopic information is required.
Usually, a data collection system stores values averaged over time. However, it is well known that a time mean average overestimates the influence of faster vehicles, and consequently overestimates the mean speed. As a direct result, densities, computed from flow and speed, are underestimated.
This paper compares the time mean speed and space mean speed, using data of individual car passages on a motorway road stretch. We show that the differences between time mean and space mean averages are substantial, up to a factor four. In particular in the lower speed regions the error is big. We indicate the considerable consequences for the jam density and shock wave speed. Finally, a fundamental diagram based on correctly averaged microscopic data can be fitted much better.
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© 2009 Springer-Verlag Berlin Heidelberg
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Knoop, V., Hoogendoorn, S.P., van Zuylen, H. (2009). Empirical Differences Between Time Mean Speed and Space Mean Speed. In: Appert-Rolland, C., Chevoir, F., Gondret, P., Lassarre, S., Lebacque, JP., Schreckenberg, M. (eds) Traffic and Granular Flow ’07. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-77074-9_36
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DOI: https://doi.org/10.1007/978-3-540-77074-9_36
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-77073-2
Online ISBN: 978-3-540-77074-9
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