We are doing a very simple analysis.

Unsignalized "T" intersection, free flow across the top of the T. We want to assess the benefits of adding a left turn bay on the free flow approach leg.

When we add the left turn bay we get a increase in delay on the approach with the bay. This doesn't make sense; the addition of the bay, which allows left turning vehicles to stop/stage, without impeding through traffic, leads to greater delay?

Comments?

It is very common with synchro's HCM analysis. you may want to look at the HCM manual unsignalized intersection analysis for the actual reasoning.

Hi,

I just noticed that I placed this question in the Synchro 6 forum.

These results are from a Sim Traffic 7 analysis. We are using results from 5 runs averaged, no issues were observed on any of the runs.

Hi,

Please feel free to send us the SYN and SIM files. You can go to Help>Support and attach these two files. It sounds like this is a SimTraffic issue and we'll run this to see what we get.

Thanks,

John