Hi,
I am working on optimization approaches on an intersection. And I have been getting some questionnable results on the simulator. I get some high troughputs of vehicle in the intersection but with big average delay of vehicles e.g :
In a scenario I get a throughput of 4544 with an average delay of 31.22 seconds and average queue length per phase of 41 meters
And in another scenario I get a 4551 throughput with an average delay of 31.26 seconds with an average queue length per phase of 39.68 meters
This compared to the average study of the same intersection we see different results, e.g in a scenario a throughput of 4343 with an average delay of 30.7 seconds and an average queue length per phase of 21.1 meters.
I am starting to question my results performance. Doesn't higher throughput mean minimum average delay and lesser queues on lanes ?
Dear Saad,
I suggest to you a links and attached files in topics.
-Traffic Parameter Definitions
ntl.bts.gov/DOCS/96100/ch02/ch02_03.html
-Department of Homeland Security Headquarters Consolidation at St. ...
https://books.google.dz/books?id=8zc3AQAAMAAJ
Best regards
Dear Saad,
There is a mathematical theorem linking some quantities: Little's law for queuing systems isL=λW: the average queue length equals the average arrival rate times the average waiting time in the system.
It means you should not diverge too much from that without clearly violating at least one hypothesis. Usual deviations are:
- bad definition/calculation of quantities (throughput...)
- using the wrong quantities (what is the delay?)
- your system is not stationary (i.e. the simulation is not long enough or you don't cut the first part that is usually very non-stationary)
- you do not compare the same quantities.
Then, I can discuss more about interpreting results, because cooperative intersection is a topic I have highly investigated. But before going to theory (optimization criteria, mathematical tools, hypotheses...), check the simple issues I have mentioned.
Best regards,
Arnaud
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