Tidbit Tuesday
Tuesday, December 10, 2019 at 4:04:36 PM
Tidbit Tuesday #9

Little Details Can Make A Big Difference

It’s important to understand and incorporate all the details of your intersection when analyzing it. Here’s an example: a backed up intersection that needs some investigation. We’ve put all our data into the HCS software to see what the model shows. Voila! But, wait, it doesn’t really match what we’ve noticed in the field. The field shows that we have a lot of queuing, but HCS results don’t show that. We double-check the Traffic Signal Inventory (TSI), phasings, timings, etc and, yep, everything matches. So, what’s the problem?

Our TSI shows that the signal is actuated, but the HCS output doesn’t match because the detection loops are broken in the field, and the signal is operating as fixed time. So, there’s a simple solution to this one. To match your analysis with the field conditions, you need to analyze it as a pretimed signal instead of what the TSI shows and document it in your findings.

If you'd like to contact us with any comments, questions or tidbits of your own, please email TrafficEngineering@la.gov.

Thanks for reading!