John Hewitt recalls "the fire station scenes were shot at the former Watford Fire Station which was then located in the High Street so green LT buses in the background would have passed this site. I recall (if my memory serves me correctly) that some of the escape/chase scenes were on the A1 - some near the one-time 'Stone House' road house at Hatfield (Herts), and again just south of what is now the Brent Cross fly-over." (thanks also to Colin Read and Bob Wingrove)