Safety vest which is called High-visibility (HV) clothing, a type of personal protective equipment, is any clothing worn that has highly reflective properties or a color that is easily discernible from any background. Yellow waistcoats worn by emergency services are a common example. Occupational wearers of clothing with high visibility features include railway and highway workers, airport workers, or other places where workers are near moving vehicles or in dark areas. Some cyclists wear high visibility clothing when riding amongst motor vehicles. Hunters may be required to wear designated high visibility clothing to prevent accidental shooting.
Experimental use of safety vest began in 1964 on the Scottish Region of British Railways. Fluorescent orange jackets, known as "fire-flies", were issued to track workers on the Pollok shields to Eglinton Street electrified section in Glasgow; they were later tried in other areas, such as Edinburgh, Aberdeen and Inverness. Train drivers operating in these areas were asked their opinion as to the effectiveness of the jackets. Following trials, high visibility clothing was issued to engineering and other staff working on the electrified lines of BR's London Midland Region in 1965. It was thought to be more important due to the higher speed of the newly electrified WCML route from Euston to Manchester, Liverpool and Birmingham. The first version was worn as a jerkin and was "visible at... half a mile in normal weather conditions."
Since then, features of high visibility clothing with reflective materials such as the EN510 quick release standard and the EN20471 high-visibility standard, have improved the effectiveness and contributed to improved safety for rail workers. The specifications for high-visibility clothing suitable for use on railways in the United Kingdom are published by the Rail Safety and Standards Board.
