Brings up a couple of questions Pretzel,,, what does estimating walk classes mean and how does it distinguish between a 5'0 tall female and a 6'4" 25 year old man? Also, if the program does not study traffic, how can it possibly be accurate?
I'll try and answer, but Big Brown Santa in a post following yours answered the walk classes well....
Time study observers are trained to estimate walk distances. They are broken into classes of walks and there are five of them. Class 1 is the shortest walk (6 to 25 feet) and class 5 is the longest (201 feet and over).
The walk time is not broken out between make / female / height / etc. Its an average time to walk. I once did the math to figure out how fast the measurement expected a walk pace to be, and as I recall it was 2.78 miles per hour. (The average person walks 3 miles per hour, so I thought that was pretty fair).
Classifying walks are a carryover from manual worksheets from many years ago. Back there was no way to estimate actual distance, so whether you walked 51 feet or 100 feet, you got the same allowance (Class 3 walk).
The new time study program measures walk distances using the satellite images, and it does it by using the measured distance instead of a walk class. So, if you walked 200 feet, you'd get a different measure in the time study than if you walked 101 feet. (Today, there is the same calculation for both)
As far as travel goes, the virtual study we have discussed does NOT measure travel. It is measured the same way as before. There is a travel chart, and the chart says that give you planned time for traveling to and from an area as well as travel time within an area. The travel time within an area is based on the number of stops you have.
During a time study, the observer can add time based on travel delays.
Of all the time study measures, travel is the least accurate.
Again, the virtual study is only changing a portion of the time study procedure. From what I hear, there will be other changes over time. Travel being one of those changes.
P-Man