The film was motivated by personal experience in that the artist's own home would also be destroyed in the process. Blight begins with views into the bedrooms of terraced houses, as they are exposed to the public gaze by demolition workers. A fragment of memoir, spoken by a resident, accompanies these shots. Gradually the story broadens to encompass a critique not just of the effect of the road locally, but of the London network of motorways of which the M11 is a part, and, by implication, the motorway network and car travel as a whole.

As it does this, however, many of the images become gradually more abstract, as we see close ups of hoardings and security fencing, before the last shot of a graphic map of the road network, an image which also resolves the relationship between image and sound.

As with Sundial, the film's "message" is conveyed without any explanatory voice-over. On a meta-critical level, Smith shows not only how a documentary can be informative without recourse to commentary, but that such a film can include abstract images and forms, and a poetic sound track in which the distinction between speech and music blurs. Thus Smith not only records a series of real events in a specific time and place, but also challenges the common understanding of documentary and experimental forms as mutually exclusive.