What is lacking is any sort of supermarket trolley discipline. The South East of England, and, in particular, Surrey, is now so overcrowded with Islamic fundamentalists, Russian oligarchs, Eastern European builders, Korean chaebol executives, refugees from France, Continental footballers and even a few locals that manoeuvering around a supermarket during the week is rather akin to taking part in a chariot race at the Circus Maximus or driving a taxi in Cairo.
What is needed is a supermarket trolley equivalent of the cycling proficiency test which all children in Britain have to take at school (with the exception of Agent Triple P, of course, who didn't learn to ride a bicyle until he was 34). Anyone who hasn't passed this test will not be allowed to push a trolley around a supermarket at all. This will be designed to prevent behaviour such as: parking your trolley at an angle across the aisle, parking your trolley right in front of a popular section, like meat, whilst you wander off to look for some lemongrass, letting horrid little children ride on the side of the trolley so that they crash into everyone else, stopping next to another trolley whilst you chat to your ghastly friend, moving down the aisle and then stopping dead whilst you take a mobile phone call and parking your trolley right next to a supermarket unloading cart which is already blocking more than half of the aisle. These are just parking offences and are nothing to the people who actually crash their trolleys into you or your trolley as they fight their way across the fruit and vegetable section under the impression that they are commanding a T34 at the Battle of Kursk. Non-compliance with the new Supermarket Trolley Proficiency code will be enforced by people carrying electrified cattle prods who just need to touch an errant trolley to ensure a healthy dose of volts for the miscreant.