I would like to see a lane utilization option for individual lanes in a link, in addition to lane groups at an intersection.

Thanks.

Hi Robert,

Thanks for the suggestions. Feel free to email us (support@trafficware.com) any further suggestions that you might have. Any examples of what you are looking for are always welcome. This helps us to fully grasp the reasoning for the change.

Thanks,

John.

I didn't think SimTraffic use lane utilization anyway, only synchro?
Eric

Hi Eric,

You are correct that SimTraffic does not use the Lane Utilization Factor (fLU) from the Synchro Lanes window. This fLU is only used for the macroscopic analysis.

Thanks,

John.

I would want to see some things to be changed. well everything may not be covered in Synchro7. Some points can be considered for Synchro 8.
-adding a transit component, for example, timely arrivals of buses
- separate designation of lanes, for example, modeling HOV lane or Bus only lanes. or even for Cars, how would you model dual left when from the inner lane you cannot make RTOR, but from the outer lane you can
- There is atleast one glitch for modeling oneway roads. There is no shared left-right lane option (when the opposing approach is oneway out) for any approach.
- The deafult allred time is 0.5 sec. is it not little low?
- The naming of intersection should be left to the users. Synchro probably takes southbound and eastbound approach for reference. that is sometime not very smart.

Some urban signal could have a 0 all-red time if the approach speeds are low enough (25mph.)
But, these are on a case by case basis.

on several models I've changed the approcah link naming to suit my purposes; for instnace, on a E-W highway that is N-S in the simulation I still label as E-W, and side streets as N-S. This also helps ensure the time-space diagrams work out properly, by keeping the approaches on the mainline opposite one another. The program appears to default to the closest true angle. if you have approaches that are closer to the NE-SW and NW-SE then they will assume those names instead. So it doesn't assume N-S E-W, it assumes the closest angle.
Eric

Please read dual right in the second comment of my posting.

I think the default values should be the ones that are most common. For instance, the Hevay vehicles to be 2%, and PHF to be 0.92. When we can get even 0% heavy vehicles, or PHF to be 1.

I do think Synchro has a preference for naming the intersection. please see this discussion below:
http://trafficware.infopop.cc/eve/forums/a/tpc/f/57.../306109739#306109739

I would vote to keep the default values right where they are, even though they may not be realistic. The reason is that it is a check for me as a state DOT who checks timing plans from others (namely consultants) to see if they have a clue! For example, the default min split for left turns is yellow + red + min green (there's not a ped phase for left turn). The default values are 3 s yellow, 1 s all red and 4 s min green. The consultants then optimize the model and in order to reduce overall intersection delay (the left turns are not efficient at all), the model will "shaft" the lefts and give them 8 seconds total split time. Well, in reality, if we only had 8 seconds total split for a left turn, our phone would ring off the hook, taking into account that start-up-loss time is 2-3 seconds anyway. We usually set min split for left turn somewhere between 12 the absolute lowest to maybe 15 seconds, depending on the intersection. However, please leave how it is so I know the competance of the one who built the model.

The reason I think the default values would be changed to fit the most common values like it is with PHF and Heavy vehicles. In many cases it is possible that the consultant (even a good one) forgets to change the All Red according to its local standard minimum, the default value would not be that far from the local standard minimum. I have worked in only couple of states, the minimum is 1 second for all red and 3.5 S for yellow. Do we think the countrywide average values for these would be different?
I think Mr Taylor has talking about something else. The unrealistic min green can be set by an engineer can still occur if the Yellow is 4 second and allred in 1 second. That issue can be solved only if you make changes after the optimization to minimize these discrepencies. (what I do as a traffic engineer in a consulting firm). The optimization philosophy in Synchro is based on overall intersection delay, not approach/movement delay.
In general I do agree that having F in left turn movement and B in Through is probably not the best option. But I can sacrifice the acceptable LOS of left turn movement (with volume of 10 vehicles), for making the LOS of opposing through movements(with volume of 2000 vehicles), both as a driver and as a traffic engineer.
Setting the minimum green for different movements should be based on movement volume, intersection geometry and jurisdiction standards. I am not sure what should be the default values for different movements, but I would think throughs might be little longer than that of lefts.