Road_names#Highways
I propose a small change for clarification on highway names with a single-letter suffix.
If there is no objection, I will make the change within a week or so.

1) remove the note that interstates with suffixes are only found in 2 states. They are found in 4 states.
2) Add 2 examples of numbered US highways with "suffixes" (divided routes and special routes)

The draft text is at Road_names#Highways.
View the difference between the two versions