Since some people asked I do it in chat (serious or not) I finally decided to map out grids for travel times from storehouses and for farms to their fields. This is the one-way time, or the time listed from storehouse to the workyard, not the cumulative extra time, so for production buildings it would be the time shown x4 for the total added time. For the farms to the fields it's the workyard to deposit time, which shows up twice so the total time is the number shown x2. For the storehouse grid the center is labeled SH and for the farm grid it's labeled FM, the grids aren't fully filled out because frankly, reaching some of the travel times is nearly impossible if you build properly.
Edit: I think when I uploaded it it shrank the farm graph, it's still somewhat readable but you might wanna save it to zoom in.
Edit 2: Oddly, some people might have some troubles readin the graph, just turn it so the lines match the diagonal grid lines in game.
I noticed that the farther away you were from the storehouse the longer it took, which makes sense, thanks for posting the patern and explaining it a bit.
Drat... I thought straight up and straight down were the same as either side... oh well, fairly minor difference. Thanks for this! Wish I'd looked for it earlier.