In alt.comp.os.windows-10, comp.sys.mac.apps, & rec.photo.digital ...
http://wetakepic.com/images/2017/09/11/chaya0.jpg

We found:
* The Mac can't embed the font in PowerPoint, and,
* The Mac can't even read an embedded front in PowerPoint, and,
* The Mac doesn't ship with a road-sign font native.

On the other hand:
* Windows can embed any font we choose into the PowerPoint, and,
* Windows can read any PowerPoint with the font already embedded, and,
* Windows (recently) ships with a road-sign font native.

The best free road-sign font choices seem to be the following:
* Good: Roadgeek (USA-standard copy)
http://www.fontspace.com/michael-d-adams/roadgeek-2005
* Better: Gothic (USA standard)
http://www.dafont.com/highway-gothic.font
* Best: Bahnschrift DIN 1451 (German standard)
https://blogs.windows.com/windowsexp...uild-16273-pc/

All are free road-sign specific fonts which can be embedded into Windows
PowerPoint so that the document itself just works on all Windows machines
with MS Office on them (whether or not the user has the latest Windows
version).

Here are some samples in our tests with the RoadGeek Narrow Series B font:
http://wetakepic.com/images/2017/09/11/chaya1.jpg
http://wetakepic.com/images/2017/09/11/chaya2.jpg
http://wetakepic.com/images/2017/09/11/chaya3.jpg
http://wetakepic.com/images/2017/09/11/chaya4.jpg
http://wetakepic.com/images/2017/09/11/chaya5.jpg
http://wetakepic.com/images/2017/09/11/chaya6.jpg
http://wetakepic.com/images/2017/09/11/chaya7.jpg

The Windows functionality/compatibility goal has been solved.
Now we only have to solve the functionality/compatibility problem for Mac.

Do any Mac experts know of a road-sign font that exists native on the Mac?