BayAreaMetro/travel-model-two

HighwayAssign.job dividing SR2 and SR3 demand by cost share factors

i-am-sijia opened this issue · 2 comments

Why does the demand need to be divided by the cost share factors (1.75 for SR2, 2.5 for SR3)? @dhensle

; shared ride 2, no value toll, exclude sr2 value toll and HOV 3+ facilities, internal demand plus intra-regional demand plus air passenger demand
pathload path = lw.gencost_s2, excludegrp = 12, 3, vol[2] = (mi.1.SR2_GP_@token_period@ + mi.1.SR2_HOV_@token_period@) / sr2costShare + mi.2.sr2 + mi.4.sr2
; shared ride 3+, no value toll, exclude sr3 value toll facilities, internal demand plus intra-regional demand plus air passenger demand
pathload path = lw.gencost_s3, excludegrp = 13, vol[3] = (mi.1.SR3_GP_@token_period@ + mi.1.SR3_HOV_@token_period@) / sr3costShare + mi.2.sr3 + mi.4.sr3

This term was not added as part of our TM2.1 update. As you can see it was in place for TM2.0 and even in TM1.5 before that (albeit with different values). I speculate that the demand matrices used here need to be scaled from person trips to vehicle trips... @jfdman do you know the origin / logic of this?

The code below in MTCTM2TripTables.java suggests the scaling of person trip to vehicle trip is done in CTRAMP. I wonder if scaling again in assignment is a mistake.

float vehicleTrips=1;
if(modelStructure.getTourModeIsS2(tripMode) && !jointTour){
vehicleTrips = 0.5f;
}else if(modelStructure.getTourModeIsS3(tripMode) && !jointTour){
String tourPurpose = tripData.getStringValueAt(i, "tour_purpose");
tourPurpose = tourPurpose.replace(" ","");
tourPurpose = tourPurpose.replace("-", "");
float occ = averageOcc3Plus.get(tourPurpose);
vehicleTrips = 1/occ;
}