Experimental use of high-visibility clothing began in 1964 on the Scottish Region of British Railways. Fluorescent orange jackets, known as "fire-flies", were issued to track workers on the Pollokshields to 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 the London Midland Region of British Railways in 1965. It was thought to be more important due to the higher speeds of the newly electrified West Coast Main Line route from London Euston to Birmingham, Manchester and Liverpool. The first version was worn as a jerkin and was "visible at ... half a mile in normal weather conditions".