Some of these features are inevitable. The economics of mass-market retailing are pulling consumers out of high streets and towards suburban shopping malls. Social changes inside families mean that more people want to shop in the evening or at weekends, and want to pick up enough groceries for a week at a time. Out-of-town shops are therefore likely to grow in number and in size. As deregulation of shopping legislation allows them to open for longer, there will be more times when those shops are open, customers are sparse, and night is falling in the car park outside.
Until now, supermarkets have had little reason to worry about security outside their doors. Last week's incidents change everything. The top management of the biggest chains, including J Sainsbury, Marks & Spencer, Tesco and Asda, are now likely to look closely at what can be done to make shopping safer for their customers.
Some precautions - better lighting, cameras, more secure perimeters - will suggest themselves. But the big retailers should resist the easy solution of uniformed security guards outside their doors, which helps to reassure customers but does little to make the far corners of the car park safer. They would do better to adopt the American practice of providing a member of staff to carry customers' shopping out to their cars free of charge. By doing so, stores could give women shoppers peace of mind - and better service at the same time.