faq 109100389

Why are vehicles in my simulation travelling so slow?

by Daniele Miranda on 2017-04-26 16:00:27

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Hello,

I am running a simulation in MATSim 8.0.1 and I am using the free version of VIS to visualise outputs. I started with TUB Tutorial and I made some modifications in the original CreateDemand class in order to create my own demand. The point is: the output I get from MATSim shows vehicles travelling very slow! Not even close to the link freespeed I've set. In addition, travel lengths shown are way longer than correct. A trip that should take about 6km is shown as taking over 300km!!

I tried the following analysis already:

• I chose an agent to follow in VIS simulation. Acording to its plan, it should have taken 17 hours to complete its trip, but VIS shows it arriving in less than 3 hours (I checked the route taken in VIS and it is exaclty the one shown in the plan);
• I checked units, everything is fine: flow capacity is given in vehicles/lane/hour, link speed in m/s;
• I also checked Geographic Coordinates, everything is UTM 23S.
• Following agens in VIA simulation, I checked that they travel faster on 60km/h links that have 3 lanes than on 80km/h links that have only 1 lane. However, none of the travel speeds seem correct.

I have absolutely no idea why vehicles are traveling so slow. Does anybody have a guess?

Thank you very much,

Daniele Miranda,

University of Brasilia, Brazil.

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Comments: 1

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Re: Why are vehicles in my simulation travelling so slow?

by Kai Nagel on 2017-04-27 16:13:41

From the hip, it looks like a unit mismatch.  MATSim will always take link lengths and link speeds from the link data, so the distance in coordinates does not matter.  So if your link is 300'000 (= 300km) long, and you have a link speed of, say, 30 (m/s), then it will take 300'000/30=10'000sec to traverse the link.  If, however, the coordinates of the toNode and fromNode of the link are only 6km apart, this will look very slow in the visualizer.