I am working on an signalized intersection with high ped traffic especially during lunch time. Is that a way to model ped movement? I have followed all the procedure of ped conflict coding and it's seem like the ped conflict have little impact on the approaches capacity.

I would like to know what impact would it be on the ped movement if I adjusted the signal timing and/or provide an exclusive ped phase.

thank,

amphone

Hi Amphone,

There are two places in Synchro for peds. Whether you code both places depends on the situation.

Volume Window, Conflicting Peds: This will reduce the saturation flow rate for the movement(s) that have peds conflicting. The amount of reduction in the saturation flow is based on the procedures of the Highway Capacity Manual. If you have a pretimed signal, and you have enough time set for peds to cross, then this is the only place you'd need to code ped information.

Phasing Window, Ped Calls per Hour. If you have an actuated phase, the amount of time given might depend on this setting. Assume you have a maximum split set at 25 seconds. Under low volumes, maybe it only operates at 10 seconds, for example. If you input in a number of ped calls, you may see the green time increase for some of the percentiles (5 percentile scenarios). This indicates that some of the percentiles are serving the peds. Normally, the number you put here would be equal to the number in the Volume window. However, if you wanted a certain number of cycles to show ped timings (say 3/5ths), increase or decrease the ped calls until 90th, 70th and 50th percentiles show 'pd'.

If you have an exclusive ped phase, handle this the same way. Code in an exclusive ped phase on the timing window and add ped calls in the Phasing window. You probably would not add conflicting peds since this is an exclusive phase.

John.

John Albeck
Trafficware

i have seen an exclusive ped phase set up with 100 calls (even synchro's help menu says to use 100 calls if it is a high pedestrian volume intersection).. how is that possible?
isn't the number of calls dependant on the cycle length, and the maximum number of ped calls per hour = number of cycles per hour ... no? since you can't have a ped phase come up more than once in a cycle...

Thanks ..

Each call is representative of a person (or group of people) pushing the ped push button in the field. Since people arrive randomly if you entered 100 calls it could mean, for example, a combination of 10 calls (or people or groups of people) in the first signal cycle, 5 in the second, 20 in the third cycle, 0 in the fourth, etc. Or it could be any other combination. Your best bet to see what exactly that combination is, is to observe it in simtraffic. If you change the random seed, you should see a different combination of calls (or people) in each signal cycle.

quote:

Originally posted by seki:
i have seen an exclusive ped phase set up with 100 calls (even synchro's help menu says to use 100 calls if it is a high pedestrian volume intersection).. how is that possible?
isn't the number of calls dependant on the cycle length, and the maximum number of ped calls per hour = number of cycles per hour ... no? since you can't have a ped phase come up more than once in a cycle...

Thanks ..

If I understand John correctly, we should put the same number for ped volumes and ped calls. irrespective of what is the difference it would make, i would disagree.
the pedestrians counted are as 1 person one ped. even if 3 persons come to intersection at the same time crosses the same approach same time, we usually count as three peds. secondly, i am crossing the road does not mean i am pushing the ped button. i can cross the road when the ped phase is on. (i wait or it was already the phase when i was crossing). thirdly, one phase can and will serve more than one ped. a jurisdiction here provided a formula to find # of ped calls from # of ped. in another discussion group i found a rule of thumb of 5 ped = 1 call.