John,

I am modeling a diamond interchange with some interesting left-turn geometry. There are dual left-turn lanes from the EB off ramp turning NB into 5 lanes. 3 of these NB lanes are through lanes and the remaining 2 lanes are left turn lanes to get onto the freeway going WB. These 2 left turn lanes are separated by a raised median to require vehicles to be in the appropriate lanes prior to the interchange. I used the O-D editor to assure no vehicles enter the freeway immediately after exiting. Vehicles queued in the EB left turn lanes only want to use 1 of the 2 left turn lanes (the right lane). Storage lanes cannot be coded for the NB left turn lanes because these lanes take up the entire link and there are 5 lanes that approach the intersection. Can I get vehicles to utilize both EB left turn lanes and turn into the 3 through lanes without giving the NB left turn lanes storage?

Brian Porter

Brian,
Lane utilization in SimTraffic is about coding the geometry as it exists (drivers will anticipate their upcoming lane changes and get in the appropriate lane based on their driver characteristics). Send us your file at support@trafficware.com and we would be glad to look it over.

Thanks,
Jeff

Trafficware