Hi All!

I noticed that simtraffic sometimes has trouble simulating vehicles at a lane drop location. Specifically at an intersection with two feeder lanes and two receiver lanes that transition into one. I have noticed two types of hang-ups with this set-up.

1. A vehicle gets jammed at the merge point and seizes the model.
2. Vehicles do not use the feeder lane that gets dropped creating excessive queues in the inside lane.

Are there any solutions to these issues?

This message has been edited. Last edited by: GEOCHA,

there are a few ways to account for this that I am aware of.
1) the good solution, but time consuming, is to adjust the mandatory distances at the node in question where the drop occurs. You'll have to vary this by trial and error to get the results you see in the field.
2) You can play with the headway adjustment on the link. This might reduce the frequency of "lock ups" but I don't think it solves the problem.
3) quick and (very) dirty solution. code a 3rd leg at a right angle to the bend node where the lane drop is, by adding a link - but do not code in any lanes going to or from it. Simtraffic now treats it as an intersection instead of a bend. This means it won't lock up, but it also doesn't have merging behavior, and as it gets congested, the vehicles go one at a time as if they're at a stop sign. This reduces the capacity of the location, but it won't lock up. If you're not interested in reporting the performance of this or nearby locations in your network, this might work for you - but then so would an exit link. As I said, its not a good solution but it won't jam up.