Services on the line are operated by London Overground. The line runs beside the West Coast Main Line (WCML) for most of its length. The London Underground Bakerloo line shares the track of the line from Queen's Park to Harrow & Wealdstone. The London Overground rolling stock used on the line is Class 378. The line is electrified with direct current, hence its name in contrast to the overhead alternating current of the adjacent WCML.