The Readers' Digest published a 33-page version of the road to Serfdom that was highly popular in the early 1950s. Now it is available again as a PDf with some introductory material, reprinted by permission by the Institute of Economic Affairs in the UK. Their site is a little hard to navigate, so I've copied it here .
In addition, the story is told in cartoon form at the end. I am told that the cartoons were especially popular in the high schools.
The book is a great resource that everyone should read. Hayek was Austrian, and although he has a perfect command of English, he writes in a German-style sentence structure which is a bit slow for Americans to read. Still, having got the idea from the Readers' Digest edition, I highly recommend the full edition.