The film's original length was 110 minutes. Bernard Herrmann composed his score for a 110-minute version; however, about 13 minutes was cut right before the film's official release. So some of Herrmann's cues didn't end up in the film. In the released version (97-98 minutes), small portions of Herrmann's cue close to the end accidentally were edited out. Some of the cues Herrmann composed for the released version didn't end up in the released cut. One of those was a cue for when the nurse walks back and enters her car.
In the beginning, Patricia Neal's character is shown working as a speech therapist. Later she mentions having had a stroke herself years earlier. Neal suffered three burst cerebral aneurysms while pregnant in 1965 and was in a coma for three weeks. She survived with the assistance of her husband Roald Dahl and a number of volunteers who developed a grueling style of therapy which fundamentally changed the way that stroke patients were treated. She subsequently relearned to walk and talk and gave birth to a healthy daughter on August 4, 1965.
The St Ives Times and Echo in Cornwall announced on 12 November 1970 that Patricia Neal was scheduled to arrive there the following week to commence location shooting on "The Road Builder." By the time MGM-EMI submitted the film to the British Board of Film Censors on 16 February 1971, the title had changed to The Night Digger (1971). It was passed with an "X" certificate, after cuts.
Although the film's running time is listed as 110 minutes, according to Filmfacts, 10 minutes of sexual scenes were cut shortly before the film was released. One of the cuts was when Maura (Patricia Neal) and Billy (Nicholas Clay) are in the kitchen, and Billy is without his shirt. Another cut scene is with Maura and Billy immediately after Maura (with her hair shortened) reveals herself to Billy.
The filming of Patricia Neal proved to be an unpleasant experience for Neal. According to author Stephen Michael Shearer in his biography of Neal, An Unquiet Life, "...Patricia sensed that the cast and crew were against her. Some actors and the director himself made unkind remarks about Patricia behind her back. After filming ended, Patricia told American celebrity writer Rex Reed, "I don't really care about making films now. I was so ambitious once. But I don't really want to work."