Please find attached my config. I've tidied things up a bit and do appear to be now getting slightly higher densities but there still seems to be a bottleneck at densities lower than I would expect.
I have also attached a few graph showing how the average gap, effective flow and average speed alter as i increase the vehsPerHour parameter. The all seem to flatline at around 6000. Many thanks for taking a look at this. On Wed, 9 Feb 2022 at 09:54, Jakob Erdmann <[email protected]> wrote: > The spacing of 90m is unexpected for your setup, With the above > configuration, you should see an average spacing of roadSpeed + vehLength + > minGap (i.e. ~20m for 13.89/ms = 50km/h road and 7.5m length+minGap). > Depending on road speed you should be seeing 1800 - 2000 v/h/lane. > If you use departSpeed="avg" instead of "max", capacity goes up to 2400 > v/h/lane > see also https://sumo.dlr.de/docs/Simulation/RoadCapacity.html > > Please post your (zipped) scenario files to figure out why you are not > seeing this. > > However, insertion flow alone will never lead to a breakdown of the flow. > For that you need some sort of speed disturbance downstream. > If you set sigma="1" you will see occasional breakdowns but they will be > short-lived (and due to a known issue with the Krauss model, this only > works at 1s step length). > An alternative for inducing break-down would be a variable-speed-sign > https://sumo.dlr.de/docs/Simulation/Variable_Speed_Signs.html > https://sumo.dlr.de/docs/Tutorials/FundamentalDiagram.html > > regards, > Jakob > > Am Di., 8. Feb. 2022 um 17:23 Uhr schrieb Ste Millington < > [email protected]>: > >> I'm struggling to get high flow rates in a simple model, just a straight >> 5km stretch of 4 lane highway. >> >> I'm using multiple flow elements with probability set close to 1. However >> i can't seem to get the flow rate to ever go above 4000 vehicles per hour. >> This only gives me 1000 vehicles per hour per lane and an average vehicle >> spacing of 90 metres. I was hoping to be able to achieve a breakdown of the >> flow. >> >> I've tried tried setting step length to 0.1 and using multiple copies of >> >> <flow id="flow_0" type="DEFAULT_VEHTYPE" begin="0.00" departSpeed="max" >> departPos="last" departLane="best" route="route_0" end="3600.00" >> probability="0.9"/> >> >> But after a certain point nothing seems to make much difference. I'm sure >> I'm doing something wrong or not perhaps just misunderstanding the traffic >> dynamics somehow. >> >> Should I be able to ramp up the flow rate to a point where the traffic >> flow breaks down? >> _______________________________________________ >> sumo-user mailing list >> [email protected] >> To unsubscribe from this list, visit >> https://www.eclipse.org/mailman/listinfo/sumo-user >> > _______________________________________________ > sumo-user mailing list > [email protected] > To unsubscribe from this list, visit > https://www.eclipse.org/mailman/listinfo/sumo-user >
<<attachment: sumoconf.zip>>
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