Board Thread:Suggestions forum/@comment-2602:30A:C7DA:7850:DDA8:E542:788A:AF23-20170727162154/@comment-26172435-20170727173013

''There was a proposal on making travelling traders spawn with increased chance near roads a few months ago. That may already cover this idea. Couldn't find it though.''

For further reference, also check these:

[Endorsed] Strangers From Distant Lands, Friends of Old...

[Endorsed] Vicinity of roads should increase structure generation chance

[Endorsed] Poets, wanderers and makers

There are many more endorsed suggestion threads on travelling traders, but of the ones I could find these are the most relevant.