Hello,

I have a question about the "Intervals" in simtraffic. When I set up the simulation runs, I go to "options--> intervals and volumes...". In the "Intervals" tab, you enter the "Seeding" and "Recording" time. I am wondering do the "Start Time" matter at all? If the peak hour start at 4:30 PM, should I enter 4:30 PM under the "Recording" for the "Start Time" and make the "Seeding" "Start Time" like 20 min (or how long should i make it) beford 4:30 PM?

[QUOTE]Originally posted by Jahid Russel:
Time of day is not an issue. your recording time would be your time of simulation. seeding time is different. roughly, the longer the seeding time is more accurate the simulation would be. (up to a certain point, see Mark's comment below. I agree with Mark you can probably be overconservative)



I have not ran anything more than 15 minutes for 1 hour run. the bigger the network longer the seeding time need be. Local DOT asked for a minimum seeding time equaling the time to need to travel from one end of the network to the other.

This message has been edited. Last edited by: Jahid Russel,

Seeding is just populating the network. For a small network of only a few close signals, seeding doesn't need to be very long at all. You are just letting your network go from 0 vehicles to a peak hour condition.

Longer isn't always better though. You may end up with over-inflated problems because your demand is being held constant over a longer than normal period.

While the "start time" won't matter to the actual simulation (only the seeding time and the recording time matter), I have found that it's always a good idea to enter the correct peak hour times, particularly if the simulation will ever be presentated at a public meeting. I once was asked why the simulation was showing 7:30 AM when I was telling everyone that it was the PM peak hour. I explained that I just never updated the simulation clock, but assured everyone that the PM volumes and timings had been used. That whole conversation (and an un-needed distraction) could easily have been avoided had I just updated the clock to match the peak hour that was being presented.

Got it, thanks