Hello, This is an artefact of the simulation step-length (vehicles can only be inserted at full seconds and this implies a narrow choice of headways when inserting at a fixed position. (There is actually an open issue that would fix this https://github.com/eclipse/sumo/issues/4277) - One workaround is the insert the vehicles with the attribute departPos="last" and departSpeed="x" where x is tuned to achieve the desired space headway based on the car-following parameters. However, this always results a fixed time headway according to the vehicle types tau parameter. - Another workaround is to lower the simulation step-length somewhat - A third approach would be to generate the vehicles individually with a script and define the desired departPos for each one
regards, Jakob 2018-08-30 5:41 GMT+02:00 Alan Dee <[email protected]>: > Hello, > > I have needed an equally spaced vehicle flow. As per the documentation > <http://sumo.dlr.de/wiki/Definition_of_Vehicles,_Vehicle_Types,_and_Routes#Repeated_vehicles_.28Flows.29> > , > vehicles should be equally spaced unless someone randomizes the flow. I > didn't randomize the flow, but I am experiencing that the vehicles do not > have the same headway. > > Here is my rou.xml file entry, and I set sigma = 0 as well. > > <flow id = "f1" color="1,1,1" begin = "0" type="Car" vehsPerHour="1500" > number="100" route="route0" departSpeed="13.9"> </flow> > > I am seeing majority of the vehicles have a headway around 27m and some > other vehicles around 40m. There is a pattern. The first 2 vehicles of > every 5 vehicles travel together (with 27m heading), and other other 3 > travel together (with 27m heading) but with 40m gap between 3rd and the > 2nd (e.g. V represents a vehicle V**V**V*****V**V*****V**V**V** > ***V**V**V**V**V*****V**V) > > I tried this as well. <flow id = "f1" color="1,1,1" begin = "0" > type="Car" period="2.4" number="100" route="route0" departSpeed="13.9"> > </flow> > > But it is the same as the previous. > > Is this is a bug or is there a workaround for this? > > Thanks, > Dee. > > _______________________________________________ > sumo-user mailing list > [email protected] > To change your delivery options, retrieve your password, or unsubscribe > from this list, visit > https://dev.eclipse.org/mailman/listinfo/sumo-user > >
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