| [sumo-user] Meso Sumo TauJF |
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Dear SUMO-Team, I’m searching for two inputs about the Tau-Meso settings. In general my network is quite large – now I’m using a small testnetwork for finding well-fitting parameters, I’ve tried to add every speed type etc. I need into this testnetwork. I’ve different speeds (there are urban, suburban, rural areas and highways) and a lot of different edge lengths.
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Are there any suggestions for the calculation of tau which Vmax I should use (the total Vmax of the hole network – the Median, Q75 etc.?), the smaller the Vmax, the higher the tau-ff
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Or is there a way that this depends on the lane type itself? (I didn’t really know how to handle this information
https://github.com/eclipse/sumo/issues/5745) The second question is, that I’m not totally sure how to calculate the tau jam-free and I would like feedback on the tau_ff if possible:
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For the tau_ff:
https://github.com/eclipse/sumo/issues/2244 and https://www.eclipse.org/lists/sumo-user/msg04886.html were looked at. I’ve tried the tau_ff once with (lcar+lgap)/speedmax and once with the formula max. flow=1/(tau_ff+(lcar+lgap)/speedmax) and I receive
the same results - but definite a lot lower than the tau-values Eissfeld uses in his examples (ex. I calculated 25m/s tau 0.3 (Eissfeld has an example with 19.6m/s with tau_ff 1.4s, for 16m/s I calculated a tau with 0.46 and for 9.7m/s I calculated a tau with
0.77)– do you know if this results are correct, though they are much lower?
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Can you give me a hint how to calculate the jam-free? (I’ve looked at the thesis of Eissfeld, I’ve found that once there he sets the value) However, I’m unsure how to calculate it when I do not have a jam-free
or jam-jam value Also I wanted to note that in the thread
https://www.eclipse.org/lists/sumo-user/msg04884.html the following is pointed out: “The other point is that in the dissertation on page 70 formula 3.24 there is a relationship between
tau_jf and tau_jj defined indicating that tau_jj is bigger than tau_jf but in SUMO it is the other way around” this is not correct – Eissfeld writes
“tau_ff<=taujf” which is handled exactly that way in the default values and is important for a static jam. Thanks in advice! Greetings, Christina |