[sumo-user] Using lane area detectors to measure queue length at on-ramp

[yu tang <herrtangvonjj@xxxxxxxxx>]

Hi all,

I am using lane area detectors to measure queue length at on-ramps that are regulated by ramp meters. I set both the simulation step size and the period of lane area detectors equal to one second. It is not surprising to find that "meanMaxJamLengthInMeters" and "maxJamLengthInMeters" have the same values, but it is confusing to find that "jamLengthInMetersInSum" can have different values. In my opinion, it should have the same values since the simulation step size is equal to the period of lane area detectors. 

Besides, I also tried to access the queue length via Traci. The method getJamLengthMeters() of lane area detectors provides the values that the same as "jamLengthInMetersInSum" does.

Can anyone explain the differences between "jamLengthInMetersInSum" and "maxJamLengthInMeters" when both the simulation step size and the period of lane area detectors are equal to one second?

Best,

Yu