Hi Simon, there are a number of variants of the Wiedemann model out there and even our implementation does not have a single reference paper behind it but at least three: * Andre Stebens - Traffic simulation with the Wiedemann model * Werner - Integration von Fahrzeugfolge- und Fahrstreifenwechselmodellen in die Nachtfahrsimulation LucidDrive * Olstam, Tapani - Comparison of Car-following models
Our implementation is only rarely used, we still use mostly our Krauss variant and therefore not very well tested, I would assume that it is nearly impossible to get similar results as in VISSIM for a reasonable complex scenario. I cannot elaborate on the individual parameters since I am no Wiedemann expert at all, but maybe the references above help (and yes, the four parameters you identified are the only ones we have implemented so far). Any improvements to or reports about experiences with the model are very welcome! Best regards, Michael Am 09.07.2014 13:44, schrieb Simon Solvason: > Dear Sumo users, > > Can you please help me out on the proper use of car-following models? > > In Denmark, the road directorate has suggested parameter values for the > Wiedemann 99 car-following model in VISSIM that should be used when > micro-simulating Danish traffic. I am wondering if I can implement the > values into Sumo-Sim? > > I have found the Wiedemann car-following model in Sumo here: > http://sumo-sim.org/doxygen/de/d42/class_m_s_c_f_model___wiedemann.html > > To enable this car-following model, I have specified > *<carFollowing-Wiedemann/>* in my *<vType>* definitions. > > How do I know which parameters of this model can I specify and what they > mean? I found this in the documentation, which appears to be the parameters > that I can edit: > > MSCFModel_Wiedemann::MSCFModel_Wiedemann ( const MSVehicleType > <http://sumo-sim.org/doxygen/de/da2/class_m_s_vehicle_type.html> * *vtype*, > > > SUMOReal > <http://sumo-sim.org/doxygen/d3/d99/windows__config_8h.html#a2481f526aef497857d2b407bc09129fd> > *accel*, > > SUMOReal > <http://sumo-sim.org/doxygen/d3/d99/windows__config_8h.html#a2481f526aef497857d2b407bc09129fd> > *decel*, > > SUMOReal > <http://sumo-sim.org/doxygen/d3/d99/windows__config_8h.html#a2481f526aef497857d2b407bc09129fd> > *security*, > > SUMOReal > <http://sumo-sim.org/doxygen/d3/d99/windows__config_8h.html#a2481f526aef497857d2b407bc09129fd> > *estimation* > ) > > Are there other parameters I can edit? What are the "security" (ZF1) and > "estimation" (ZF2) parameters? > > These are the parameters available in VISSIM, of which the first three are > the most important (as long as the others are specified correctly): > > *CC0 Standstill distance:* Desired distance between lead and following > vehicle at v = 0 kph (*minGap *in Sumo, I believe) > *CC1 Headway Time: *Desired time in seconds between lead and following > vehicle (*tau *in Sumo, I believe) > *CC2 Following Variation: *Additional distance over safety distance that > a vehicle requires > *CC3 Threshold for Entering ‘Following’ State:* Time in seconds before a > vehicle starts to decelerate to reach safety distance (negative) > *CC4 Negative ‘Following’ Threshold:* Specifies variation in speed > between lead and following vehicle > *CC5 Positive ‘Following Threshold’:* Specifies variation in speed > between lead and following vehicle > *CC6 Speed Dependency of Oscillation:* Influence of distance on speed > oscillation > *CC7 Oscillation Acceleration:* Acceleration during the oscillation > process > *CC8 Standstill Acceleration:* Desired acceleration starting from > standstill (*accel* in Sumo, I believe) > *CC9 Acceleration at 80 kph:* Desired acceleration at 80 kph > > > If anyone has any additional information about these parameters, or on how > to use this car-following model, it would be greatly appreciated. > > Best Regards > Simon > ------------------------------------------------------------------------------ > Open source business process management suite built on Java and Eclipse > Turn processes into business applications with Bonita BPM Community Edition > Quickly connect people, data, and systems into organized workflows > Winner of BOSSIE, CODIE, OW2 and Gartner awards > http://p.sf.net/sfu/Bonitasoft > _______________________________________________ > sumo-user mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/sumo-user > ------------------------------------------------------------------------------ _______________________________________________ sumo-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sumo-user
