The advantages of electrification in the main lie in lessened operating costs, better running schedules, improvement of terminals, betterment of employees' working conditions, and cleaner and more attractive service generally. Against these advantages have to be placed high initial expenses in the provision of track equipment, sub-stations, transmission lines, locomotives, motor and trailer cars, and so on. In Europe electrification has been found a decidedly paying proposition, from the economic viewpoint it having given complete satisfaction in Switzerland, Norway, Sweden, Holland and Italy. In Britain, on the the Southern Railway, there has been built up the world's biggest suburban electrification system, page 47 which is also a decided financial success and a big asset in meeting the competition of the road carrier. A good deal of doubt still, unfortunately, exists as to the ideal system of electrification. Direct current has been adopted as standard in Britain, and is also employed extensively in the United States, France, Italy and Holland, at voltages varying from 600 to 3,000. Elsewhere, three-phase and single-phase current is favoured, at varying periodicities. There seems a great need for the technical experts to get their heads together on the standardisation question, and the establishment of definite standards would probably do more than anything else to speed up railway electrification throughout the world.