Hello, I'm trying to set a simulation for an isolated signalized intersection. The westbound approach includes a left turn lane, a through lane, a shared through/right turn lane, and a free flow right turn lane with 600 feet of storage. The shared right turn lane is a yield condition. The free flow right turn lane feeds into a northbound lane that terminates approximately 800 feet north of the intersection. Using default values in SimTraffic, I'm not getting enough utilization of the free flow lane (vehicles will sit in a queue in the shared through/right turn lane) at the signal when they could easily change into the free flow lane and proceed to the northbound link. Using the default values for mandatory distance and positioning distance (Cycle Length of 80 / Speed Limit of 45), I get a little less than half the right turns using the free flow lane. I'd like this number to be about 80%.
Is tweaking these values my only option? Does anyone have any suggestions? What unintended consequences may come from tweaking these numbers too much?
reducing your mandatory lane change distances will help. Without hard control of lane utilization, you're left with trial and error calibration of this value.
Does anyone have any experience with tweaking the mandatory lane changing distances? I've messed around with the numbers and gotten better results, but with the detriment of some through vehicles unrealistically jumping into the free flow lane for a few hundred feet and then getting back into the through lane when the signal is red (causing extra, unrealistic delay).
Do I need to modify the MD and PD and MD2 and PD2 for both the westbound link and the northbound receiving link? Or just a few of the numbers?mlspayd@garverUSA.com
