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With nearly a quarter million riders served each day, is the busiest light rail system in the. There is no standard definition, but in the United States (where the terminology was devised in the 1970s from the engineering term ), light rail operates primarily along exclusive and uses either individual tramcars or multiple units coupled to form a train that is lower capacity and lower speed than a long heavy or system.

A few light rail networks tend to have characteristics closer to or even commuter rail; some of these heavier rapid transit-like systems are referred to as. Other light rail networks are tram-like in nature and partially operate on streets. Light rail systems are found throughout the world, on all inhabited continents. They have been especially popular in recent years due to their lower capital costs and increased reliability compared with heavy rail systems. Streetcar built by in Ontario Many original tram and streetcar systems in the United Kingdom, United States, and elsewhere were decommissioned starting in the 1950s as the popularity of the automobile increased. Britain abandoned its last tram system, except for, by 1962. Although some traditional trolley or tram systems exist to this day, the term 'light rail' has come to mean a different type of rail system.

Modern light rail technology has primarily West German origins, since an attempt by to introduce a new American light rail vehicle was a technical failure. After World War II, the Germans retained many of their streetcar networks and evolved them into model light rail systems ( Stadtbahnen). Except for, all large and most medium-sized German cities maintain light rail networks. The basic concepts of light rail were put forward by H. Dean Quinby in 1962 in an article in Traffic Quarterly called 'Major Urban Corridor Facilities: A New Concept'. Quinby distinguished this new concept in rail transportation from historic streetcar or tram systems as: • having the capacity to carry more passengers • appearing like a train, with more than one car connected together • having more doors to facilitate full utilization of the space • faster and quieter in operation The term light rail transit (LRT) was introduced in North America in 1972 to describe this new concept of rail transportation.

The first of the new light rail systems in North America began operation in 1978 when the Canadian city of, adopted the German system, followed three years later by, and. The concept proved popular, and although Canada has few cities big enough for light rail, there are now at least 30. Britain began replacing its run-down local railways with light rail in the 1980s, starting with the and followed by the (DLR) in London. The historic term was used because it dated from the British, although the technology used in the DLR system was at the high end of what Americans considered to be light rail.

The trend to light rail in the United Kingdom was firmly established with the success of the system in 1992. Definition [ ]. 's 101 trolley pulling into near Philadelphia The opposite phrase heavy rail, used for higher-capacity, higher-speed systems, also avoids some incompatibilities in terminology between British and American English, as for instance in comparing the and the. Conventional rail technologies including, freight,, and urban transit systems are considered 'heavy rail'. And are even 'lighter,' at least in terms of capacity. Is a separate technology that has been more successful in specialized services than in a commuter transit role.

Like most light rail systems, the (Tenerife, Spain) includes some operation at street level, but separated from other traffic Due to varying definitions, it is hard to distinguish between what is called light rail, and other forms of urban and commuter rail. A system described as light rail in one city may be considered to be a streetcar or tram system in another.

Conversely, some lines that are called 'light rail' are in fact very similar to; in recent years, new terms such as have been used to describe these medium-capacity systems. Some 'light rail' systems, such as, bear little similarity to urban rail, and could alternatively be classified as commuter rail or even inter-city rail. In the United States, 'light rail' has become a catch-all term to describe a wide variety of passenger rail systems. There is a significant difference in cost between these different classes of light rail transit. Tram-like systems are often less expensive than metro-like systems by a factor of two or more. Lower capacity [ ] The most difficult distinction to draw is that between light rail and streetcar or tram systems. There is a significant amount of overlap between the technologies, many of the same vehicles can be used for either, and it is common to classify streetcars or trams as a subcategory of light rail rather than as a distinct type of transportation.

The two general versions are: • The traditional type, where tracks and trains run along the streets and share space with road traffic. Stops tend to be very frequent, but little effort is made to set up special stations.

Because space is shared, the tracks are usually visually unobtrusive. • A more modern variation, where the trains tend to run along their own, separated from road traffic. Stops are generally less frequent, and the vehicles are often boarded from a platform. Tracks are highly visible, and in some cases significant effort is expended to keep traffic away through the use of special signaling, with gate arms, or even a complete separation with non-level crossings. Higher capacity [ ].

's is a line consisting of both conventional track and a short on-street section At the highest degree of separation, it can be difficult to draw the line between light rail and, as in the case of 's hanging rail system, the, or London's, which would likely not be considered 'light' were it not for the contrast between it and the. These may be considered to be rather than 'light rail' lines. In Europe, however, the term light rail is increasingly used to describe any rapid transit system with a fairly low frequency or short trains compared to heavier mass rapid systems such as the or Singapore's. For instance, the and in are often referred to as 'light rail', despite being fully segregated, mostly elevated railways. Gadwin Print Screen Crack Wallpaper. This phenomenon is quite common in Chinese cities, where elevated light metro lines in,, and are called light rail lines. In North America, such systems are not considered light rail. Mixed systems [ ] Many systems have mixed characteristics.

Indeed, with proper engineering, a rail line could run along a street, then go underground, and then run along an elevated viaduct. For example, the Los Angeles 's 'light rail' has sections that could alternatively be described as a tramway, a light metro, and, in a narrow sense, rapid transit. This is especially common in the United States, where there is not a popularly perceived distinction between these different types of urban rail systems. It is even possible to have high-floor rapid transit cars run along a street, like a tram; this is known as. Speed and stop frequency [ ] In some areas, 'light rail' may also refer to any rail line with frequent low speeds or many stops in a short distance. This inherits the old definition of in the UK. Hong Kong's is an example of this, although it is also called 'light rail' because it is a lower-scale system than the rest of the MTR.

Sprinter in the San Diego area uses DMUs and is targeted towards a commuter rail audience; however, because of the large number of stops along the line, it is called light rail. Reference speed from major light rail systems, including station stop time, is shown below. System Average speed (mph) Baltimore 24 Dallas (Red Line) 21 Dallas (Blue Line) 19 Denver (Alameda-Littleton) 38 Denver (Downtown-Littleton) 26 Los Angeles (Blue Line) 24 Los Angeles (Green Line) 38 Salt Lake City 24 However, low top speed is not always a differentiating characteristic between light rail and other systems. For example, the LRVs used in the and other North American LRT systems have a top speed of 106 kilometres per hour (66 mph) while the trains on the all-underground can only reach a top speed of 72 kilometres per hour (45 mph).

Light rail vehicles have higher top and average speeds than Montreal Metro or trains. The main difference is that Montreal Metro and New York City Subway trains carry far more passengers than any North American LRT system, and the trains have faster acceleration, making station-to-station times relatively short in their densely populated urban areas. Most light rail systems serve less densely populated cities and suburbs where passenger traffic is not high, but low cost combined with high top speed may be important to compete with automobiles.

System-wide considerations [ ] Many light rail systems—even fairly old ones—have a combination of both on- and off-road sections. In some countries (especially in Europe), only the latter is described as light rail. In those places, trams running on mixed rights-of-way are not regarded as light rail, but considered distinctly as streetcars or trams. However, the requirement for saying that a rail line is 'separated' can be quite low—sometimes just with concrete 'buttons' to discourage automobile drivers from getting onto the tracks. Some systems such as are truly mixed but closed to traffic, with light rail vehicles and traditional buses both operating along a common right-of-way. Some systems, such as the in New York City, the in London, and in, Malaysia, have dispensed with the need for an operator.

The was an early adopter of driverless vehicles, while the operates the same trains as Vancouver, but uses drivers. In most discussions and comparisons, these specialized systems are generally not considered light rail. Track gauge [ ] Historically, the has had considerable variations, with common in many early systems. However, most light rail systems are now. Older standard-gauge vehicles could not negotiate sharp turns as easily as narrow-gauge ones, but modern light rail systems achieve tighter turning radii by using. An important advantage of standard gauge is that standard railway maintenance equipment can be used on it, rather than custom-built machinery. Using standard gauge also allows light rail vehicles to be moved around, conveniently using the same tracks as freight railways.

Another factor favoring standard gauge is that laws are making mandatory, and there is generally insufficient space for wheelchairs to move between the wheels in a narrow-gauge layout. Furthermore, standard-gauge rolling stock can be switched between networks either temporarily or permanently and both newly built and used standard-gauge rolling stock tends to be cheaper to buy, as more companies offer such vehicles. Comparison to other rail transit modes [ ] With its mix of right-of-way types and train control technologies, LRT offers the widest range of latitude of any rail system in the design, engineering, and operating practices. The challenge in designing light rail systems is to realize the potential of LRT to provide fast, comfortable service while avoiding the tendency to overdesign that results in excessive capital costs beyond what is necessary to meet the public's needs. Alternative Differences Light rail vehicles (LRVs) are distinguished from (RRT) vehicles by their capability for operation in mixed traffic, generally resulting in a narrower car body and articulation in order to operate in a street traffic environment. With their large size, large turning radius, and often an electrified, RRT vehicles cannot operate in the street.

Since LRT systems can operate in existing streets, they can often avoid the cost of expensive subway and elevated segments that would be required with RRT. Conversely, LRVs generally outperform traditional streetcars in terms of capacity and top-end speed, and almost all modern LRVs are capable of. The latest generation of LRVs is considerably larger and faster, typically 29 metres (95 ft) long with a maximum speed of around 105 kilometres per hour (65 mph). A variation considered by many cities is to use historic or replica cars on their streetcar systems instead of modern LRVs. A heritage streetcar may not have the capacity and speed of an LRV, but it will add to the ambiance and historic character of its location. A derivative of LRT is light rail rapid transit (LRRT), also referred to as light metro. Such railways are characterized by exclusive rights of way, advanced train control systems, short headway capability, and floor-level boarding.

These systems approach the passenger capacity of full metro systems, but can be cheaper to construct due to LRVs generally being smaller in size, turning tighter curves and climbing steeper grades than standard RRT vehicles, and having a smaller station size. The term interurban mainly refers to rail cars that run through streets like ordinary streetcars (trams), but also between cities or towns, often through rural environments. In the period 1900–1930, interurbans were very common in the US, especially in the. Some of them, like the, the J. Brill, and the, were the of their time, with an in-service speed of up to about 145 km/h (90 mph). In Europe interurbans are making a comeback as ' (locally known under different names) that operate on both railway and light rail tracks, often with different voltage.

The is one well known example. Typical rolling stock [ ] The railcar in the following chart is not generally considered to be a 'light rail' vehicle (it is actually a vehicle), and is only included for comparison purposes. Type Rapid transit (heavy rail) Light rail Tram, or streetcar Heritage streetcar Manufacturer Rohr Siemens Skoda Gomaco Trolley Co. Model Replica Birney Width 3.2 metres (10 ft) 2.7 metres (8.9 ft) 2.6 metres (8.53 ft) 2.62 metres (8.6 ft) Length 22.9 metres (75 ft) 27.7 metres (91 ft) 20.13 metres (66.0 ft) articulated 15.16 metres (49.7 ft) Weight (empty) TBD 48.6 t 28.8 t 23.5 t Capacity 150 max. 72 seats, 220 max. 30 seats, 157 max.

40 seats, 50 max. Top speed 125 km/h (78 mph) 106 km/h (66 mph) 70 km/h (43 mph) 48 km/h (30 mph) Typical consist 4–10 vehicles 2–5 vehicles 1 vehicle 1 vehicle Train operation [ ]. For more details on this topic, see. An important factor crucial to LRT is the train operator. Unlike rail rapid transit, which can travel unattended under automatic train operation (ATO), safe, high-quality LRT operation relies on a human operator as a key element. The reason that the operator is so important is because the train tracks often share the streets with automobiles, other vehicles, and pedestrians. If trains were fully automated on roads, nobody would be there to stop the train if a car pulled in front of it.

Light rail trains are actually very sturdily built for passenger safety, and to reduce damage from impacts with cars. Principle Of Business Management In Hindi. [ ] Floor height [ ]. For more details on this topic, see. The latest generation of LRVs has the advantage of partially or fully low-floor design, with the floor of the vehicles only 300 to 360 mm (11.8 to 14.2 in) above the top of the rail, a feature not found in either rapid rail transit vehicles or streetcars. This allows them to load passengers, including those in wheelchairs or strollers, directly from low-rise platforms that are little more than raised sidewalks. This satisfies requirements to provide access to disabled passengers without using expensive and delay-inducing wheelchair lifts, while also making boarding faster and easier for other passengers.

[ ] Power sources [ ] supply electricity to the vast majority of light rail systems. This avoids the danger of passengers stepping on an electrified. The uses an inverted third rail for its electrical power, which allows the electrified rail to be covered and the power drawn from the underside.

Trams in, France, use a where the power is only switched on beneath the trams, making it safe on city streets. Several systems in Europe and a few recently opened systems in North America use -powered trains. [ ] Tram and other light rail transit systems worldwide [ ]. Main articles: and Around the world there are many tram and streetcar systems.

Some date from the beginning of the 20th century or earlier, but many of the original tram and streetcar systems were closed down in the mid-20th century, with the exceptions of many Eastern Europe countries. Even though many systems closed down over the years, there are still a number of tram systems that have been operating much as they did when they were first built over a century ago.

Some cities (such as Los Angeles and ) that once closed down their streetcar networks are now restoring, or have already rebuilt, at least some of their former streetcar/tram systems. Most light rail services are currently committed to articulated vehicles like modern LRVs, i.e. Trams, with the exception of large underground metro or rapid transit systems. A LRT train on boarding Efficiency [ ] for light rail may be 120 passenger miles per gallon of fuel (or equivalent), but variation is great, depending on circumstances. Comparison with high capacity roads [ ] While the table above compares the maximum capacity of each mode, the average use of a lane might be quite different, based on a number of factors. One line of light rail (requires 25' Right of Way) has a theoretical capacity of up to 8 times more than one 12' lane of freeway (not counting buses) during peak times.

Roads have ultimate capacity limits that can be determined. They usually experience a chaotic breakdown in flow and a dramatic drop in speed (colloquially known as a ) if they exceed about 2,000 vehicles per hour per lane (each car roughly behind another). Since most people who drive to work or on business trips do so alone, studies show that the average car occupancy on many roads carrying commuters is only about 1.5 people per car during the high-demand periods of the day. This combination of factors limits roads carrying only automobile commuters to a maximum observed capacity of about 3,000 passengers per hour per lane. The problem can be mitigated by introducing high-occupancy vehicle () lanes and programs, but in most cases the solution adopted has been to add more lanes to the roads. By contrast, light rail vehicles can travel in multi-car trains carrying a theoretical ridership up to 20,000 passengers per hour in much narrower, not much more than two car lanes wide for a system. They can often be run through, or placed in the.

If run in streets, trains are usually limited by city block lengths to about four 180-passenger vehicles (720 passengers). Operating on two-minute headways using traffic signal progression, a well-designed two-track system can handle up to 30 trains per hour per track, achieving peak rates of over 20,000 passengers per hour in each direction. More advanced systems with separate rights-of-way using can exceed 25,000 passengers per hour per track. Practical considerations [ ] Most light rail systems in the United States are limited by demand rather than capacity (by and large, most North American LRT systems carry fewer than 4,000 persons per hour per direction), but Boston's and San Francisco's light rail lines carry 9,600 and 13,100 passengers per hour per track during rush hour. Elsewhere in North America, the and have higher light rail ridership than Boston or San Francisco.

Systems outside North America often have much higher passenger volumes. The is one of the highest capacity ones, having been upgraded in a series of expansions to handle 40,000 passengers per hour per direction, and having carried as many as 582,989 passengers in a single day on its. It achieves this volume by running four-car trains with a capacity of up to 1,350 passengers each at a frequency of up to 30 trains per hour. However, the Manila light rail system has full grade separation and as a result has many of the operating characteristics of a metro system rather than a light rail system. A capacity of 1,350 passengers per train is more similar to heavy rail than light rail. A (BRT) system using dedicated lanes can have a theoretical capacity of 3,600 passengers per hour per direction (30 buses per direction, 120 passengers in ).

BRT is an alternative to LRT, at least if very high capacity is not needed. Using buses, roads can achieve a much higher commuter capacity than is achievable with passenger cars.

To have 30 buses per direction an hour, buses must have priority at traffic lights and have their own dedicated lanes. Buses can travel closer to each other than rail vehicles because of better braking capability. However, each bus vehicle requires a single driver, whereas a light rail train may have three to four cars of much larger capacity in one train under the control of one driver, or no driver at all in fully automated systems, increasing the labor costs of high-traffic BRT systems compared to LRT systems. The peak passenger capacity per lane per hour depends on which types of vehicles are allowed at the roads. Typically roadways have 1,900 passenger cars per lane per hour (pcplph). If only cars are allowed, the capacity will be less and will not increase when the traffic volume increases. When there is a bus driving on this route, the capacity of the lane will be more and will increase when the traffic level increases.

And because the capacity of a light rail system is higher than that of a bus, there will be even more capacity when there is a combination of cars and light rail. Table 3 shows an example of peak passenger capacity. Car Car + bus Car + light rail Low volume 900 1,650 2,250 Medium volume 900 2,350 3,250 High volume 900 3,400 4,600 (Edson & Tennyson, 2003) Safety [ ] While many claim that light rail is safe, research by car bloggers [ ] suggest otherwise. For example, an analysis of data from the 505-page National Transportation Statistics report published by the US Department of Transportation shows that light rail fatalities are higher than all other forms of transportation except motorcycle travel (31.5 fatalities per 100 million miles). However, the National Transportation Statistics report published by the US Department of Transportation states that 'Caution must be exercised in comparing fatalities across modes because significantly different definitions are used. In particular, Rail and Transit fatalities include incident-related (as distinct from accident-related) fatalities, such as fatalities from falls in transit stations or railroad employee fatalities from a fire in a workshed. Equivalent fatalities for the Air and Highway modes (fatalities at airports not caused by moving aircraft or fatalities from accidents in automobile repair shops) are not counted toward the totals for these modes.

Thus, fatalities not necessarily directly related to in service transportation are counted for the transit and rail modes, potentially overstating the risk for these modes.' Health impact of light rail [ ]. Main article: Integration with bicycles [ ] Light rail lines have various policies on bicycles.

Some fleets restrict bicycles on trains during peak hours. Some light rail systems, such as the St. Louis MetroLink, allow bicycles on the trains, but only in the rear sections of cars. Some light rail lines, like San Francisco's, allow only on board.

In some systems dedicated bike parking is available at select stations and others are integrated with local systems. Construction and operation costs [ ] The cost of light rail construction varies widely, largely depending on the amount of tunneling and elevated structures required. A survey of North American light rail projects shows that costs of most LRT systems range from $15 million to over $100 million per mile. Is by far the most expensive in the US, at $179 million per mile, since it includes extensive tunneling in poor soil conditions, elevated sections, and stations as deep as 180 feet (55 m) below ground level. This results in costs more typical of subways or rapid transit systems than light rail.

At the other end of the scale, four systems (Baltimore, Maryland; Camden, New Jersey; Sacramento, California; and Salt Lake City, Utah) incurred construction costs of less than $20 million per mile. Over the US as a whole, excluding Seattle, new light rail construction costs average about $35 million per mile. By comparison, a freeway lane expansion typically costs $1.0 million to $8.5 million per mile for two directions, with an average of $2.3 million. However, freeways are frequently built in suburbs or rural areas, whereas light rail tends to be concentrated in urban areas, where right of way and property acquisition is expensive. Similarly, the most expensive US highway expansion project was the ' in Boston, Massachusetts, which cost $200 million per lane mile for a total cost of $14.6 billion. Since a light rail track can carry up to 20,000 people per hour as compared with 2,000–2,200 vehicles per hour for one freeway lane, light rail is comparable in construction cost to freeways on a per passenger-mile basis [ ]. For example, in Boston and San Francisco, light rail lines carry 9,600 and 13,100 passengers per hour, respectively, in the peak direction during rush hour.

Combining highway expansion with LRT construction can save costs by doing both highway improvements and rail construction at the same time. As an example, Denver's rebuilt interstate highways 25 and 225 and added a light rail expansion for a total cost of $1.67 billion over five years. The cost of 17 miles (27 km) of highway improvements and 19 miles (31 km) of double-track light rail worked out to $19.3 million per highway lane-mile and $27.6 million per LRT track-mile.

The project came in under budget and 22 months ahead of schedule. LRT cost efficiency improves dramatically as ridership increases, as can be seen from the numbers above: the same rail line, with similar capital and operating costs, is far more efficient if it is carrying 20,000 people per hour than if it is carrying 2,400. The, Alberta, used many common light rail techniques to keep costs low, including minimizing underground and elevated trackage, sharing transit malls with buses, leasing rights-of-way from freight railroads, and combining LRT construction with freeway expansion. As a result, Calgary ranks toward the less expensive end of the scale with capital costs of around $24 million per mile. However, Calgary's LRT ridership is much higher than any comparable US light rail system, at 300,000 passengers per weekday, and as a result its capital efficiency is also much higher. Its capital costs were one-third those of the, a comparably sized US system built at the same time, while by 2009 its ridership was approximately three times as high. Thus, Calgary's capital cost per passenger was much lower than that of San Diego.

Its operating cost per passenger was also much lower because of its higher ridership. A typical C-Train vehicle costs only 163 (equivalent to $192 in 2016) per hour to operate, and since it averages 600 passengers per operating hour, Calgary Transit estimates that its LRT operating costs are only 27 cents per ride, versus $1.50 per ride on its buses. Compared to buses, costs can be lower due to lower labor costs per passenger mile, higher ridership (observations show that light rail attracts more ridership than a comparable bus service) [ ] and faster average speed (reducing the number of vehicles needed for the same service frequency). While light rail vehicles are more expensive to buy, they have a longer useful life than buses, sometimes making for lower life-cycle costs. Variations [ ] Trams operating on mainline railways [ ]. On the, trams sometimes share mainline tracks with heavy rail trains Around,, and in Germany, dual-voltage light rail trains partly use mainline railroad tracks, sharing these tracks with heavy rail trains.

In the, this concept was first applied on the. This allows commuters to ride directly into the city centre, rather than taking a mainline train only as far as a central station and then having change to a tram. In France, similar are planned for Paris,, and; further projects exist. In some cases, tram-trains use previously abandoned or lightly used heavy rail lines in addition to or instead of still in use mainline tracks. Some of the issues involved in such schemes are: • compatibility of the safety systems • power supply of the track in relation to the power used by the vehicles (frequently different voltages, rarely third rail vs overhead wires) • width of the vehicles in relation to the position of the • height of the platforms There is a history of what would now be considered light rail vehicles operating on heavy rail tracks in the US, especially in the case of. Notable examples are trains running on the high-speed third rail line (now the ). Such arrangements are almost impossible now, due to the refusing (for crash safety reasons) to allow non-FRA compliant railcars (i.e., subway and light rail vehicles) to run on the same tracks at the same times as compliant railcars, which includes locomotives and standard railroad passenger and freight equipment.

Notable exceptions in the US are the from to and Austin's, which have received exemptions to the provision that light rail operations occur only during daytime hours and freight service only at night, with several hours separating one operation from the other. The in Ottawa also has freight service at certain hours. Third-rail power for trams [ ]. Main article: When electric streetcars were introduced in the late 19th century, was one of the first ways of supplying power, but it proved to be much more expensive, complicated, and trouble-prone than. When electric street railways became ubiquitous, conduit power was used in those cities that did not permit overhead wires.

In Europe, it was used in London, Paris, Berlin, Marseille, Budapest, and Prague. In the United States, it was used in parts of New York City and Washington, DC. Technology was investigated for use on the of Australia for the light rail, though power from was ultimately utilized for that system. In the French city of, the is powered by a in the city centre, where the tracks are not always segregated from pedestrians and cars. The third rail (actually two closely spaced rails) is placed in the middle of the track and divided into eight-metre sections, each of which is powered only while it is completely covered by a tram. This minimises the risk of a person or animal coming into contact with a live rail.

In outer areas, the trams switch to conventional. The Bordeaux power system costs about three times as much as a conventional overhead wire system, and took 24 months to achieve acceptable levels of reliability, requiring replacement of all the main cables and power supplies. Operating and maintenance costs of the innovative power system still remain high. However, despite numerous service outages, the system was a success with the public, gaining up to 190,000 passengers per day. See also [ ].