Hello everyone:

simtraffic have 10 different driver types with 10% each. how can i change the driver type in driver parameter? suppose i want to make 50% drivers aggressive, meaning driver type 10, how can i do that? your suggestion will be appreciated. thanks. the delay result and travel time i am getting from simtraffic is way less than the actual field data, so i am thinking of changind driver types. is there anything else i can do? thank.

Hello,

In SimTraffic, you have 10% of each Driver Type (DT) and this cannot be changed. You can always change the parameters of one to more closely match the other, but I don't really suggest this.

If you have travel time issues, it could be a huge variety of things. You don't have any artifical bottlenecks downstream? If that is the case, this will spillback and slow vehicles. This is not uncommon to have an issue upstream or downstream that causes the problem. you'll want to look at the animation and results very carefully.

Thanks,

John.

thanks john. you are right, i actually have bottlenecks at some signalized intersections. the issue is, there is median in the field and the roadway has TWLTL, so the left turning drivers will use TWLTL as left turn storage and will not block through traffic so much, however, in the model, we can not do that, and with storage length and median, i see a lot of left turning vehicles blocking the through traffic. also, what i noticed was there is a big delay at the first and last node of the segment in the model, meaning suppose i have 20 intersections, when going eastbound i found huge delay at intersection 1 and on goign westbound, i see that kind of huge delay in intersection 10.

how good is it to decrease the vehicle length?

I would suggest increasing the left turn storage to match the actual queues in the field that extend beyond the formal storage into the TWLTL (if I understand your situation correctly). While it is nice to make the model LOOK like reality, it is far better to me to make it behave like reality even if that means making it look wrong. Explaining that to the layperson is another matter...

Don, I agree with you. i also just did the same thing that you mentioned. lets see how the result comes. thanks for your input.

I also agree with Don. I've done field observations to determine how much shoulder drivers were willing to use as right turn lane.

Eric Royer
Caltrans