Thanks for the Note. :)

According to dashcam footage:

- "Robertridge Drive" = Every street sign along the road.
- "Robert Ridge Drive" = 2 streetsigns in the N (very beginning) of the street/development.

The street sign colors are:

- 1st kind = "green with white lettering".
- 2nd kind = "blue with white lettering".

- - -

Note: The St. Charles County GIS data also agrees with NO-SPACE version:

- "Robertridge Drive"

A ton of the other streetsigns in the area also:

1. Combine "-ridge" with the first name before.
2. Have a same named Drive+Court.

There is also a "Robertridge Court" in the far SW corner of this development. And that's verified correct by dashcam footage + GIS too.

- - -

So, I'd say the actual name of the street is with:

- NO-SPACE

- - -

Note 2: I corrected 2 other street errors in the area:

- https://www.openstreetmap.org/changeset/152060678

Maybe the are a few more errors/misspellings in this surrounding area too.