Simpson was a fair and tolerant man, but also expected the same high standards of others that he set for himself and was a great believer in discipline. He believed in a more equal police force, where senior officers and lower ranks had a closer relationship. This was somewhat marred by the promotion of fellow Hendon graduates as Deputy Commissioner and all four Assistant Commissioners; the short-lived Hendon experiment was never popular with most officers, although actually these appointments were made by the Crown on the advice of the Home Secretary. He strove, with some success, to improve the deteriorating relationship between the police and the public and encouraged the public to "have a go" against crime, although he did issue a warning against tackling armed criminals. He was an enthusiastic supporter of crime prevention and the use of police dogs, and also greatly expanded the Police Cadets. He established the Obscene Publications Squad, Drugs Squad (1963), Special Patrol Group (1961), Art Squad (1967) and Antiques and Philately Squad (1967), laid the foundations for the Scenes of Crime Branch established shortly after his death, and greatly expanded the Flying Squad. He introduced personal radios and the Unit Beat system (1967), whereby the use of panda cars was greatly expanded for patrol purposes. He reorganised the Metropolitan Special Constabulary to integrate them more into the divisions. He introduced traffic wardens and fixed penalty parking fines.