A road safety film for children demonstrating what not to do when playing on the street or cycling on the road. Instructions on how to cross safely come form 'Safety Sam' and information is given about getting getting bicycle breaks checked.

The film opens with a logo for the Royal Society for the Prevention of Accidents and the title 'Safe or Sorry'. The film shows the police demonstrating “Bad road behaviour” to a crowd of school children. They act out various scenarios involving accidents with cars, bicycles and pedestrians. The commentary states: “You would not play football in a busy street ... or step out from behind a parked lorry”. “Safety Sam” in a white costume and a triangle on his hat shows the children how it is done. The rules include: “look right, look left and look right again...”. The film informs children what to do when riding a bicycle, showing both bad behaviour and good behaviour. Out on the street, a child crashes into a policeman due to poor breaks. Children are instructed to: “Make sure your bicycle is in good repair”. A poster reads: “Cyclists! Your Safety depends on Your Bicycle”. A boy is seen taking his bike to a bicycle repair shop. The 'End' title changes into: ‘There is a quick END to careless people’ and ‘You can’t be TOO careful’.

The Blackheath Film Unit was based in Leatherhead, Surrey. It specialised in producing educational, scientific, industrial and public relations films. Amongst these were a number of road safety films including 'Unguarded Moment' and 'Safe or Sorry'.