As of October 2015, Hong Kong has the world's only exclusively double-decker tramway system. 320 km (199 mi) was in Minneapolis-Saint Paul in 1947: There streetcars ended 31 October 1953 in Minneapolis and 19 June 1954 in St. Paul. In the US, Bachmann Industries is a mass supplier of HO streetcars and kits. Tramways with trams (British English) or street railways with streetcars (North American English) were common throughout the industrialised world in the late 19th and early 20th centuries but they had disappeared from most British, Canadian, French and US cities by the mid-20th century. The overhead power lines and supporting poles utilized by trams (except for those using a third rail) can be unsightly and contribute to visual pollution. Steel wheel and rail particulates are produced but regular wheel alignment and flexible track mounting can reduce emissions. Tram tracks can be hazardous for cyclists, as bikes, particularly those with narrow tyres, may get their wheels caught in the track grooves. World's longest 9-sectioned 56 metres (184 ft)-meter articulated tram vehicle CAF Urbos 3/9 started operation in Budapest in 2016. Škoda ForCity vehicles family allows expansion of length up to 72 metres (236 ft) with 539 passengers.
O scale trams are also very popular among tram modellers because the increased size allows for more detail and easier crafting of overhead wiring. As tram lines are permanent this allows local authorities to redevelop and revitalise their towns and cities provided suitable planning changes are made. When wet, tram tracks tend to become slippery and thus dangerous for bicycles and motorcycles, especially in traffic. It is possible to close the grooves of the tracks on critical sections by rubber profiles that are pressed down by the wheelflanges of the passing tram but that cannot be lowered by the weight of a cyclist. There have also been some new tram systems in cities that never previously had them. Trams that are compatible with heavy rail systems are called tram-trains, while those that can use subway tunnels are called semi-metro, pre-metro or U-Stadtbahn. However, transportation planners use noise mitigation strategies to minimise these effects. Most of all, the potential for decreased private motor vehicle operations along the tram's service line because of the service provision could result in lower ambient noise levels than without.
Rail transport can expose neighbouring populations to moderate levels of low-frequency noise. The opening of new tram and light rail systems has sometimes been accompanied by a marked increase in car accidents, as a result of drivers' unfamiliarity with the physics and geometry of trams. Saint Petersburg's tram system has declined in size since the fall of the Soviet Union. Since 1961, the Melbourne system (recognised as the world's largest) has assumed Sydney's title as the largest network in Australia. The Toronto streetcar system had similarly become an iconic symbol of the city, operating the largest network in the Americas as well as the only large-scale tram system in Canada (not including light rail systems, or heritage lines). Though such increases may be temporary, long-term conflicts between motorists and light rail operations can be alleviated by segregating their respective rights-of-way and installing appropriate signage and warning systems. Trams are in a period of growth, with about 400 tram systems operating around the world, several new systems being opened each year, and many being gradually extended.
The Sydney tram network, before it was closed on 25 February 1961, had 291 km (181 mi) of route, and was thus the largest in Australia. New systems have been built in the United States, United Kingdom, Ireland, Italy, France, Australia and many other countries. Some of these systems date from the late 19th or early 20th centuries. Since 2000, 78 systems have opened while 13 have closed. The team members have already won the prize for the most disrupted biological clocks. Since 1980 trams have returned to favour in many places, partly because their tendency to dominate the roadway, formerly seen as a disadvantage, is considered to be a merit since it raises the visibility of public transport (encouraging car users to change their mode of travel), and enables streets to be reconfigured to give more space to pedestrians, making cites more pleasant places to live. They carry 13.5 billion passengers a year, 3% of all public transport passengers. This goal was to be met by setting a Renewable Fuel Standard of 35 billion US gallons (130,000,000 m3) by 2017 and Hybrid Battery Replacement mn by reforming and modernizing Corporate Average Fuel Economy (CAFE) standards. The average U.S. household consumes about 10,000 kWh of electricity each year.
