I looked through the group archive but didn't see a discussion of this topic.
I'm getting ready to start hand laying the track for the HOn3 portion of my layout. When looking at pictures of the D&RGW between Antonito and Durango in the late 40's and early 50's it looks like the ties aren't spaced much farther apart than the width of a 5"x7" tie. Many ties seem to be placed even closer than 7" apart. This is quite a bit closer together than the ties on the Micro Engineering flex track that I used on my last layout.
This surprised me a bit. What are the experts here in this group using for the spacing between their ties?