Synchro vs Simtraffic Reports

[Zeggelaar]

Synchro and Simtraffic output results are often similar but quite different in magnitude, Simtraffic delays and queuing are usually larger than Synchros.

95th Percentile Queuing especially, as Synchro does not take into account spillback from insufficiently long turning bays. For example left turns movements backing into through lanes, blocking thru movements and increasing delay.

What is the general practice of deciding which report to accept?

Which one, Synchro or Simtraffic has been everyones preference?

 

[kellig]

It really depends on your objective and what level of planning/analysis you are looking at. Synchro is a macroscopic model and simtraffic is a microscopic model. Take a look at the FHWA Traffic Analysis toolbox; it has a good comparative description that might help you to make a decision about which would be most appropriate for your particular application.

 

[teeman]

Synchro and Simtraffic are two different animals. The first is essentially a statistical model of intersection operations. If all your input parameters are good it should give you a reasonable approximation of intersection operations. The second is a simulation model. Simulation models track the movement of individual vehicles through the network, keeping track of variables associated with that vehicle.

You have control over the much of the data input to Synchro and can refine the Synchro input to better reflect observed operating conditions. Simtraffic is more of a black box. Data in, simulation out. The programs can complement each other. Simtraffic may illustrate some elements of the network that don't stand out in the synchro analysis. Simtraffic is also useful for presentations.

I have a fair degree of confidence in Synchro outputs. I consider Simtraffic to be a supplement to, not a substitute for the Synchro analysis.