Player size and modelling.

Hi, I have a question which is either going to be very hard to answer, or very easy to answer.

I am in the process of modelling a Russian Kishinev cargo ship for gmod, in 3DS Max.
My goal is to have interiors in the bridge, some (few) cabins, the engine room, and stairways to connect them all.
My question now is… Is there any way to know how wide to make walkways in the phys model so they can be walked through?
I know there are many problems with scaling and a known comparison, but I thought i would ask if anyone happens to have any ingenious idea of creating walk able spaces…

Thanks in advance.

I know that the collision model for players is 32x32x72 so you should probably make them at minimum 34-36 units wide if it’s a really tight space. Also adding sort of ‘guides’ for parts that players might get caught at.

Like this:

Here’s a documentation of commonly used dimensions:

Sweet, that answers the bulk of my question… now, transferring that data to 3DS Max… I can create a reference rectangle that’s 2.5 times taller than it is wide, then scale it to roughly match the walkways, and adjust walkways accordingly… But is that the easiest way? Is there any conversion, even a rough one, from source units to 3DS Max generic units?

EDIT: alternatively, 3DS units could be switched to metres and converted to source units…

EDIT2: From looking at the dimensions page, it seems easier than I thought… By my calculations, walkways should be 64 X 64 X 128 3DS Max generic unis… (extra width, minimum being 48 X 48 X 108, but on a moving prop, it would be better to have wide walkways to avoid getting stuck)