Have you looked at the 31 kitchen design rules? I think the situation you describe is a combination of rules 6, 7 & 8, and I'd say you'd want that walkway to be 54-60" wide.

Here is a link that might be useful: 31 kitchen design rules

Do you really need a prep sink that large? It seems that a much smaller one will do.

We could get away with a smaller one but the wife and I decided to just make them the same size. Even if we shrink it, it wouldn't increase the spacing in the isle. If we shrink the primary sink, then we could gain 3" on the aisle.

Hi n123 - where is your dishwasher? Are you planning on a truly counter depth fridge - what is the actual depth of your fridge with handles? Do you have a link to a larger picture? The dimensions on yours are hard to read because groupwise shrank it.

If you use a smaller prep sink, I would think that you could increase the isle width between the refrigerator and the end of the island. It is nice to have the isle wide enough that someone can get by a person that is getting into the refrigerator, otherwise, that becomes a choke point.

Here is a better resolution picture.
The fridge is full depth, we are having large cabinets built to case it out. There are two dishwashers flanking the island sink.

Hmm it seems gardenweb might be scaling the image. A better link is below on imgur.

Thanks!

Here is a link that might be useful: Kitchen image

I think I might see some confusion, sorry for not being clear. Our "prep" (really, just secondary for cooking helpers) is the non-island sink. Our primary sink is on the island. We currently have them both as 33" but we could shrink the island to 30" and gain 3" of walking space.

The function is backwards then. Put the DW's on the cleanup sink, and have a smaller prep sink with a 42"-48" aisle between it and the cooking zone. You've got pinch points between the seating and pantry, and the pantry and fridge wall cabinets, and the fridge and island end. Those are all too small.

The function is backwards then. Put the DW's on the cleanup sink, and have a smaller prep sink with a 42"-48" aisle between it and the cooking zone. You've got pinch points between the seating and pantry, and the pantry and fridge wall cabinets, and the fridge and island end. Those are all too small.

I agree with hollysprings on the size of sinks and placement of dishwashers. I'd just add that you should consider the placement of flatware, plate, and glass/cup storage - best to have those very close to the dishwasher to facilitate unloading.