In the original story, the character of Nan was a male, Ronald. Rod Serling believed that a female in the situation would be reacted to with more feeling by audiences. She was named after one of his daughters.
Lucille Fletcher got the idea for this story in 1940 when she and her husband Bernard Herrmann were driving cross-country from New York to California. On the first day of the trip they saw the same odd-looking man on the side of the road in two different locations. She found the occurrence rather eerie and thought it might be a good concept for a story.
Alfred Hitchcock tried to purchase the rights to the radio play for his television series Alfred Hitchcock Presents (1955), for $2000 but his bid was rejected. Nevertheless, Cayuga Productions was able to obtain rights to Lucille Fletcher's script for $2000 and $1100 for each episode re-run.
The voice-over narration references the radio-play source of the episode. The original radio play was originally produced for a summer replacement series called "Suspense" on September 2, 1942 and starred Orson Welles. The program was so popular that Welles restaged the same script for "Philip Morris Playhouse" on October 15, 1942 and "Mercury Summer Theater on the Air" on June 21, 1946. Musical cues Bernard Herrmann composed for the 1946 radio production were re-scored for this episode.
In a strange coincidence before the filming of Twilight Zone, Inger Stevens attempted to commit suicide on New Year's Day, 1959 by swallowing 25 sleeping pills and a quantity of ammonia in an attempt to take her own life. On another occasion, she narrowly missed being killed in a fiery plane crash. In 1961, she was the last passenger to leave a jet that crashed on landing and exploded after her exit.