Hi Clare.  Thanks for contacting the Extension Master Gardener Helpline.

You don't indicate any particular species of Sorghum, and an initial look at the literature would indicate that most, if not all, Sorghum species (think Sorghum halapense or Johnsongrass) are highly invasive, enough to make it onto most international lists of highly discouraged species.

However, there is one Sorghum cross called Sudangrass that might work.  The following two articles may give you more information.

https://www.uvm.edu/vtvegandberry/factsheets/Sudax.html

http://www.hort.cornell.edu/bjorkman/lab/covercrops/pdf/sudangrass.pdf

But I note that you want to use it as an ornamental landscape element not a crop, and since all the literature talks about Sorghum Sudangrass as a cover crop or forage crop, it may be more vigorous (and short-lived) than you need.  I'm assuming you're looking for screening and perhaps noise reduction when you say you want a buffer between your lawn and the road.  Would any of the other ornamental grasses do the same with perhaps a little more finesse than Sorghum?  It's true that few of them reach the potential height of the Sorghum, but many are reliably perennial in Zones 3 and 4 so you wouldn't have to reseed every year.  Many have beautifully airy seed heads that would provide some separation without the "cornfield wall" effect of a Sorghum field.  The following link may give you some other ideas.

https://hgic.clemson.edu/factsheet/ornamental-grasses-and-grass-like-plants/

I hope this information is helpful.  Good luck!

Jessie, Extension Master Gardener Helpline Volunteer