This film, which is also being shown on January 3rd, 4th, 20th and 26th, is part of the Ingmar Bergman season at BFI Southbank. Full details here.
Chicago Reader review:
An archetypal Ingmar Bergman film, and one of his best (1957). An aging professor (Victor Sjostrom, who as a director was Sweden's D.W. Griffith) making a long journey by car takes the opportunity to rummage through his past, wondering for the first time what kind of man he was. There's a lot of allegorical baggage on board, but the film's virtues lie in its relative simplicity. With Ingrid Thulin and Bibi Andersson.
Here (and above) is the trailer.