In civil engineering (more specifically highway engineering ), grade separation is a method of aligning a junction of two or more surface transport axes at different heights (grades) so that they will not disrupt the traffic flow on other transit routes when they cross each other. The composition of such transport axes does not have to be uniform; it can consist of a mixture of roads , footpaths , railways , canals , or airport runways . Bridges (or overpasses , also called flyovers), tunnels (or underpasses ), or a combination of both can be built at a junction to achieve the needed grade separation.
101-596: The Mattapan Line (alternatively the Mattapan Trolley and historically the Ashmont–Mattapan High-Speed Line ) is a partially grade-separated light rail line which forms part of the MBTA's Red Line rapid transit line. The line, which runs through Boston and Milton, Massachusetts , opened on August 26, 1929, as a conversion of a former commuter rail line. It exclusively uses PCC streetcars built in
202-493: A jet engine-powered snowblower , officially the Portec RMC Hurricane Jet Snow Blower, model RP-3, dubbed "Snowzilla". Snowzilla weighs 26,000 pounds (12,000 kg), measures 8 by 12 by 27 feet, and is powered by a Westinghouse J34 turbojet engine. It uses approximately 500 US gallons (1,900 L; 420 imp gal) of jet fuel per line clearing run. Other T lines simply run regular trains to clear
303-724: A "light rail" vehicle (it is a heavy rail vehicle), and is only included for comparison purposes. Low-floor LRVs have the advantage of a low-floor design, allowing them to load passengers directly from low-rise platforms that can be little more than raised curbs. High-floor light rail systems also exist, featuring larger stations. Historically, the track gauge has had considerable variations, with narrow gauge common in many early systems. However, most light rail systems are now standard gauge . 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 articulated cars . An important advantage of
404-458: 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. 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. Seattle's new light rail system
505-403: A chaotic breakdown inflow and a dramatic drop in speed (a traffic jam ) if they exceed about 2,000 vehicles per hour per lane (each car roughly two seconds 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 rush hour periods of
606-1102: A common right-of-way (however, Link converted to full separation in 2019). Some systems, such as the AirTrain JFK in New York City, the DLR in London, and Kelana Jaya Line in Kuala Lumpur , have dispensed with the need for an operator. The Vancouver SkyTrain was an early adopter of driverless vehicles, while the Toronto Scarborough rapid transit operated the same trains as Vancouver, but used drivers. In most discussions and comparisons, these specialized systems are generally not considered light rail but as light metro systems. Around Karlsruhe , Kassel , and Saarbrücken in Germany, dual-voltage light rail trains partly use mainline railroad tracks, sharing these tracks with heavy rail trains. In
707-452: A grade-separated junction may be referred to as a grade separation or as an interchange – in contrast with an intersection , at-grade , a diamond crossing or a level crossing , which are not grade-separated. Roads with grade separation generally allow traffic to move freely, with fewer interruptions, and at higher overall speeds; this is why speed limits are typically higher for grade-separated roads. In addition, reducing
808-416: A highway) that they cross. However, grade-separated pedestrian crossings with steps introduce accessibility problems. Some crossings have lifts , but these can be time-consuming to use. Grade-separated roads that permit for higher speed limits can actually reduce safety due to 'weaving' (see below) as well as a perceived sense of safety. The term is most widely applied to describe a road junction in which
909-416: 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 BRT systems compared to LRT systems. BRT systems are also usually less fuel-efficient as they use non-electrified vehicles. The peak passenger capacity per lane per hour depends on which types of vehicles are allowed on
1010-435: A live rail. In outer areas, the trams switch to conventional overhead wires . 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 the 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,
1111-536: A longer distance. Light rail cars are often coupled into multiple units of two to four cars. Light rail systems may also exhibit attributes of heavy rail systems, including having downtown subways, as in San Francisco and Seattle . Light rail is designed to address a gap in interurban transportation between heavy rail and bus services, carrying high passenger numbers more quickly than local buses and more cheaply than heavy rail. It serves corridors in which heavy rail
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#17328527395751212-631: A more diverse range of design characteristics than LRT, depending on the demand and constraints that exist, and BRT using dedicated lanes can have a theoretical capacity of over 30,000 passengers per hour per direction (for example, the Guangzhou Bus Rapid Transit system operates up to 350 buses per hour per direction). For the effective operation of a bus or BRT system, buses must have priority at traffic lights and have their dedicated lanes, especially as bus frequencies exceed 30 buses per hour per direction. The higher theoretical of BRT relates to
1313-414: A partial grade separation will accomplish more improvement than for a road), and because at-grade railway connections often take up significant space on their own. However, they require significant engineering effort, and are very expensive and time-consuming to construct. Grade-separated pedestrian and cycling routes often require modest space since they do not typically intersect with the facility (such as
1414-407: 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 the heavy rail than light rail. Bus rapid transit (BRT) is an alternative to LRT and many planning studies undertake a comparison of each mode when considering appropriate investments in transit corridor development. BRT systems can exhibit
1515-530: A top speed of 55–71.5 miles per hour (88.51–115.1 km/h) depending on the system, while the trains on the all-underground Montreal Metro can only reach a top speed of 72 kilometres per hour (44.74 mph). LACMTA light rail vehicles have higher top and average speeds than Montreal Metro or New York City Subway trains. 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
1616-474: 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. The development of technology for low-floor and catenary-free trams facilitates the construction of such mixed systems with only short and shallow underground sections below critical intersections as
1717-462: Is a generic international English phrase for types of rail systems using modern streetcars/trams, which means more or less the same thing throughout the English-speaking world . Light rail systems can range from trams runnig in streets along with other traffic, to semi-metro systems having portions of grade separated track. People movers are even "lighter", in terms of capacity. Monorail
1818-565: Is a separate technology that has been more successful in specialized services than in a commuter transit role. The use of the generic term light rail avoids some serious incompatibilities between British and American English . The word tram , for instance, is generally used in the UK and many former British colonies to refer to what is known in North America as a streetcar , but in North America tram can instead refer to an aerial tramway , or, in
1919-602: Is a significant amount of overlap between the technologies; similar rolling stock may 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. However, some distinctions can be made, though systems may combine elements of both. Low-floor light rail lines tend to follow a reserved right-of-way and with trains receiving priority at intersections, and tend not to operate in mixed traffic, enabling higher operating speeds. Light rail lines tend to have less frequent stops than tramways, and operate over
2020-576: Is an integral part of the modern MBTA transit system rather than a tourist attraction. A rebuild of the line for modern light rail vehicles is planned. The Dorchester and Milton Branch Railroad opened in December 1847 from Neponset on the Old Colony Railroad main line to Mattapan station in Dorchester via Milton Mills (later Milton Lower Mills, then simply Milton). The line was immediately leased by
2121-560: 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
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#17328527395752222-426: Is especially important for wheelchair access, as narrower gauges (e.g. metre gauge) can make it challenging or impossible to pass the tram's wheels. 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. Overhead lines supply electricity to
2323-498: Is expensive. Similarly, the most expensive US highway expansion project was the " Big Dig " in Boston, Massachusetts, which cost $ 200 million per lane mile for a total cost of $ 14.6 billion. 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. For example, in Boston and San Francisco, light rail lines carry 9,600 and 13,100 passengers per hour, respectively, in
2424-419: Is fully grade-separated, i.e. traffic on one road does not have to stop at yield lines or signals on one road, but may have to do so when switching to the other: On roadways with grade-separated interchanges, weaving is a result of placing an exit ramp a short distance after an entry ramp, causing conflicts between traffic attempting to leave the roadway at the next junction and traffic attempting to enter from
2525-575: Is hard to distinguish between what is called light rail, and other forms of urban and commuter rail. A system described as a 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 very similar to rapid transit ; in recent years, new terms such as light metro have been used to describe these medium-capacity systems. Some "light rail" systems, such as Sprinter , bear little similarity to urban rail, and could alternatively be classified as commuter rail or even inter-city rail. In
2626-549: Is impractical. Light metro systems are essentially hybrids of light rail and rapid transit. Metro trains are larger and faster than light rail trains, with stops being further apart. 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 Metro Rail 's A Line "light rail" has sections that could alternatively be described as
2727-708: Is known as a flying junction and one which is not a level junction . In 1897, the London and South Western Railway (LSWR) made use of a flying junction at Worting Junction south of Basingstoke to allow traffic on the Salisbury and Southampton routes to converge without conflicting movements; this became known as "Battledown Flyover". Also in Britain, the Southern Railway later made extensive use of flying junctions on other parts of its busy former LSWR main line. Today in Britain,
2828-480: 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 Line 1 . 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
2929-407: Is similar to that of a traditional tram, while operating at a higher capacity and speed, often on an exclusive right-of-way. In broader use, it includes tram-like operations mostly on streets. A few light rail networks have characteristics closer to rapid transit or even commuter rail , yet only when these systems are fully grade-separated are they referred to as light metros . The term light rail
3030-580: The Boston Elevated Railway (BERy) was first constructing its rapid transit Cambridge–Dorchester line in the early 1910s, plans called for the line to be extended south from Andrew to Codman Square via Edward Everett Square , Columbia Square, and Mount Bowdoin. The route would have paralleled the New Haven's Shawmut branch and Midland Division . By the end of that decade, however, passenger traffic on both New Haven-owned lines had been decimated by
3131-535: The Cádiz TramBahia , where trams share track with commuter and long-distance trains from the main terminus in the city and curve off to serve cities without a railway connection. Some of the issues involved in such schemes are: There is a history of what would now be considered light rail vehicles operating on heavy rail rapid transit tracks in the US, especially in the case of interurban streetcars . Notable examples are Lehigh Valley Transit trains running on
Mattapan Line - Misplaced Pages Continue
3232-469: The Great Central Railway , built between 1896 and 1899, was the first fully grade-separated railway of this type in the UK. This also applies to light rail and even to street cars . Attempts have been made to increase the capacity of railways by making tracks cross in a grade-separated manner, as opposed to the traditional use of flat crossings to change tracks. A grade-separated rail interchange
3333-657: The Green Line ) was reported to be the most viable option. As of 2024, the MBTA plans to have Type 9 LRVs replace the PCC streetcars. The Mattapan Line fleet of PCC streetcars consist of ten units, of which 6 are in service. Of the six in service, 3 have been rebuilt. [REDACTED] Media related to Ashmont–Mattapan High Speed Line at Wikimedia Commons Other transit in the United States: Grade separation In North America,
3434-735: The London Underground and the New York City Subway . Conventional rail technologies including high-speed , freight, commuter , and rapid transit urban transit systems are considered "heavy rail". The main difference between light rail and heavy rail rapid transit is the ability for a light rail vehicle to operate in mixed traffic if the routing requires it. The world's first electric tram operated in Sestroretsk near Saint Petersburg , Russia , invented and operated on an experimental basis by Fyodor Pirotsky in 1880. The first tramway
3535-624: The Netherlands , this concept was first applied on the RijnGouweLijn . This allows commuters to ride directly into the city center, rather than taking a mainline train only as far as a central station and then having to change to a tram. In France, similar tram-trains are planned for Paris, Mulhouse , and Strasbourg ; 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. In 2022, Spain opened
3636-831: The O-Train Trillium Line in Ottawa, Ontario , Canada, the River Line in New Jersey , United States, and the Sprinter in California , United States, which use diesel multiple unit (DMU) cars. Light rail is different from the British English term light railway , long-used to distinguish railway operations carried out under a less rigorous set of regulations using lighter equipment at lower speeds from mainline railways. Light rail
3737-673: The Philadelphia and Western Railroad high-speed third rail line (now the Norristown High-Speed Line ). Such arrangements are almost impossible now, due to the Federal Railroad Administration 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
3838-530: The medians of roads . 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 moving block signaling can exceed 25,000 passengers per hour per track. Most light rail systems in
3939-517: The 1860s, subways are far more common today in Europe, especially in countries such as the Netherlands and Denmark where cycling is strongly encouraged. Long underpasses may be called tunnels . Light rail vehicle Light rail (or light rail transit , abbreviated to LRT ) is a form of passenger urban rail transit that uses rolling stock derived from tram technology while also having some features from heavy rapid transit . The term
4040-477: The 1940s. Passengers must transfer at Ashmont to access the rest of the Red Line, which uses heavy rail metro rolling stock. The trolley's 2.6-mile (4.2 km) route is used only by streetcars and has just two public grade crossings. All stations have low platforms , but all except Valley Road have been retrofitted with wheelchair lifts or wooden ramps for accessibility. Unlike most heritage streetcar lines, it
4141-619: The 1970s was proven to have been a technical failure by the following decade. After World War II, the Germans retained many of their streetcar networks and evolved them into model light rail systems ( Stadtbahnen ). With the exception of Hamburg , all large and most medium-sized German cities maintain light rail networks. The concept of a "limited tramway" was proposed by American transport planner H. Dean Quinby in 1962. Quinby distinguished this new concept in rail transportation from historic streetcar or tram systems as: The term light rail transit
Mattapan Line - Misplaced Pages Continue
4242-570: The A4/M5 junction west of Bristol . Weaving can often cause side-on collisions on very fast roads with top speeds of up to 200 kilometres per hour, as well as the problem of blind spots. Where junctions have unusual designs weaving can be a problem other than on the main road. An example of this can be found at Junction 7 of the M6, where traffic joining the roundabout from the M6 Eastbound off-slip must weave with
4343-639: The BERy's network of electrified streetcar lines, which connected to rapid transit trains at Forest Hills , Egleston , Dudley Square , and Andrew . Around 1920, BERy reached an agreement with the New Haven and the Boston Transit Commission to pursue the Dorchester Circuit Plan. Under that plan, a bidirectional rapid transit loop would run south from Andrew along the Old Colony main line, take over
4444-453: The Eastbound off-slip must leave. Weaving can be alleviated by using collector/distributor roads or braided ramps to separate entering and exiting traffic. In railway construction, grade separation also means the avoidance of level crossings by making any roads or footpaths crossing the line either pass under or over the railway on bridges . This greatly improves safety and is crucial to
4545-491: The French city of Bordeaux , the tramway network is powered by a third rail in the city center, 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 minimizes the risk of a person or animal coming into contact with
4646-557: The MassDOT board in June 2016, allocated $ 9 million to the line including $ 3.7 million for maintaining the PCC cars. The plan also allocated $ 5 million for "PCC Car Replacement-Alternative Service" which was to be used for future funding should an alternate form of transportation be decided upon. In 2017, MBTA began a $ 7.9 million project to overhaul the trolleys and update the propulsion systems, but further problems such as fluctuations in power damaged
4747-555: The Old Colony as its Milton branch. The Old Colony built the Shawmut Branch Railroad from Harrison Square on the main line to Milton Lower Mills via Peabody Square in 1872. Most Mattapan passenger service switched to use the new branch east of Milton, as it ran through dense urban neighborhoods rather than swamps. The Old Colony Railroad and its branches were acquired by the New York, New Haven and Hartford Railroad in 1893. When
4848-519: The Red Line designation was also applied to the line, which had been known as 28 Mattapan–Ashmont. On March 18, 1968, the Neponset River flooded the line at Milton . Restoration work began at 6:00 am on March 21 as the waters receded; service was resumed by 4:30 pm. In January 1981, the MBTA proposed to close the Mattapan Line at all times beginning that March due to severe budget issues. The closure
4949-624: The Shawmut Branch and Milton branch to Mattapan, cut over to the Midland Division on a tunnel, and return to Andrew via the Midland Division right-of-way and another tunnel segment. Although the Midland Branch served more populated areas, real estate deals along the Shawmut branch stood to benefit key state politicians. Construction of a rapid transit extension to Mattapan via the Shawmut branch
5050-642: The US are the NJ Transit River Line from Camden to Trenton and Austin's Capital MetroRail , which have received exemptions to the provision that light rail operations occur only during daytime hours and Conrail freight service only at night, with several hours separating one operation from the other. The O-Train Trillium Line in Ottawa also has freight service at certain hours. With its mix of right-of-way types and train control technologies, LRT offers
5151-455: 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 lane 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
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#17328527395755252-634: The United States and in North America . In Britain, modern light rail systems began to appear in the 1980s, starting with the Tyne and Wear Metro from 1980 and followed by the Docklands Light Railway (DLR) in London in 1987, continuing into the 1990s including the establishment of the Manchester Metrolink in 1992 and the Sheffield Supertram from 1994. Due to varying definitions, it
5353-583: The United States are limited by demand rather than capacity (by and large, most 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 Calgary C-Train and Monterrey Metro have higher light rail ridership than Boston or San Francisco. Systems outside North America often have much higher passenger volumes. The Manila Light Rail Transit System
5454-472: The United States, "light rail" has become a catch-all term to describe a wide variety of passenger rail systems. Light rail corridors may constitute a fully segregated corridor, a dedicated right-of-way on a street, an on-street corridor shared with other traffic, a corridor shared with other public transport, or a corridor shared with pedestrians. The most difficult distinction to draw is that between low-floor light rail and streetcar or tram systems. There
5555-415: The ability of buses to travel closer to each other than rail vehicles and their ability to overtake each other at designated locations allowing express services to bypass those that have stopped at stations. However, to achieve capacities this high, BRT station footprints need to be significantly larger than a typical LRT station. In terms of cost of operation, each bus vehicle requires a single driver, whereas
5656-515: The capacity of a road compared to an identical road with at-grade junctions. For instance, it is extremely uncommon to find an at-grade junction on a British motorway ; it is all but impossible on a U.S. Interstate Highway , though a few do exist. If traffic can traverse the junction from any direction without being forced to come to a halt, then the junction is described as fully grade separated or free-flowing . These junctions connect two freeways: These junctions connect two roads, but only one
5757-862: The case of the Disney amusement parks , even a land train . (The usual British term for an aerial tramway is cable car , which in the US usually refers to a ground-level car pulled along by subterranean cables .) The word trolley is often used as a synonym for streetcar in the United States but is usually taken to mean a cart, particularly a shopping cart, in the UK and elsewhere. Many North American transportation planners reserve streetcar for traditional vehicles that operate exclusively in mixed traffic on city streets, while they use light rail to refer to more modern vehicles operating mostly in exclusive rights of way, since they may operate both side-by-side targeted at different passenger groups. The difference between British English and American English terminology arose in
5858-470: The city of Boston, but most of the southern half of its route is in the northern part of the neighboring town of Milton . It follows the right-of-way of two former Old Colony Railroad branches which had commuter rail service until the 1920s. Much of the route parallels the Neponset River , crossing it twice. The right-of-way is owned by the MBTA and has only two at-grade crossings on its 2.6-mile (4.2 km) route. Between Cedar Grove and Butler stations,
5959-421: The closure of Glasgow Corporation Tramways (one of the largest in Europe) in 1962. Although some traditional trolley or tram systems continued to exist in San Francisco and elsewhere, the term "light rail" has come to mean a different type of rail system as modern light rail technology has primarily post-WWII West German origins. An attempt by Boeing Vertol to introduce a new American light rail vehicle in
6060-725: The complexity of traffic movements reduces the risk of accidents . Grade-separated road junctions are typically space-intensive, complicated, and costly, due to the need for large physical structures such as tunnels, ramps, and bridges. Their height can be obtrusive, and this, combined with the large traffic volumes that grade-separated roads attract, tend to make them unpopular to nearby landowners and residents. For these reasons, proposals for new grade-separated roads can receive significant public opposition. Rail-over-rail grade separations take up less space than road grade separations: because shoulders are not needed, there are generally fewer branches and side road connections to accommodate (because
6161-415: 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 ( HOV ) lanes and ride-sharing programs, but in most cases, policymakers have chosen to add more lanes to the roads, despite a small risk that in unfavorable situations an extension of
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#17328527395756262-571: The direct flow of traffic on one or more of the roads is not disrupted. Instead of a direct connection, traffic must use on and off ramps ( United States , Australia , New Zealand ) or slip roads ( United Kingdom , Ireland ) to access the other roads at the junction. The road which carries on through the junction can also be referred to as grade separated . Typically, large freeways , highways , motorways , or dual carriageways are chosen to be grade separated, through their entire length or for part of it. Grade separation drastically increases
6363-750: The direct translation, which is city rail (the Norwegian term, by bane , means the same). However, UMTA finally adopted the term light rail instead. Light in this context is used in the sense of "intended for light loads and fast movement", rather than referring to physical weight. The infrastructure investment is also usually lighter than would be found for a heavy rail system. The American Public Transportation Association (APTA), in its Glossary of Transit Terminology, defines light rail as: ...a mode of transit service (also called streetcar, tramway, or trolley) operating passenger rail cars singly (or in short, usually two-car or three-car, trains) on fixed rails in
6464-415: The existing PCC cars, procurement of new replicas of historic cars, and turning the line into a busway. Local politicians and citizens who live along the line have voiced their concerns over the potential conversion of the line into a busway and prefer that the route be maintained as using rail technology. In January 2019, eventual conversion for use of new light rail vehicles (or Type 9 LRVs transferred from
6565-557: The faster speed requires grade separation. Therefore, many high speed lines are elevated, especially in Taiwan and Japan , where population density alongside high speed lines is higher than in France, Italy or Germany. In the United States, a flying junction on the Nickel Plate Road through Cleveland , Ohio , United States was completed in 1913. The most frequent use was later found on
6666-500: The former Pennsylvania Railroad main lines. The lines are included as part of the Northeast Corridor and Keystone Corridor now owned by Amtrak . The most complex of these junctions, near Philadelphia Zoo , handles railway traffic for Amtrak, SEPTA , New Jersey Transit , Norfolk Southern , CSX Transportation , and Conrail . In what is known as "area 1520" , which includes the former Soviet Union and other regions using
6767-503: The four operating trains in early 2018. On February 5, 2018, it was reported that eight more trolleys were going to re-enter service in 2019, the fixes will prolong the lifespan of the trains by another 7 to 8 years. After several delays, the first rebuilt trolley entered service in March 2022. The MBTA also announced in 2018 that it was studying alternatives again to running trolleys. Alternatives that were being considered were further repairs of
6868-453: The late 19th century when Americans adopted the term "street railway", rather than "tramway", with the vehicles being called "streetcars" rather than "trams". Some have suggested that the Americans' preference for the term "street railway" at that time was influenced by German emigrants to the United States (who were more numerous than British immigrants in the industrialized Northeast), as it is
6969-524: The latter is described as light rail. In those places, trams running on mixed rights-of-way are not regarded as a 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 Seattle's Link had on-road mixed sections but were closed to regular road traffic, with light rail vehicles and buses both operating along
7070-556: The latter rebuild, the cars were repainted from their former Green Line paint scheme to a brighter orange and cream design, similar to their original coloring. The cars also carry a unique geographic MBTA logo, reminiscent of the old Metropolitan Transit Authority map logo found on the cars between 1948 and 1955. On several occasions, the MBTA has proposed to replace the PCC streetcars either with newer trolleys or with buses, and has met with substantial community opposition on each occasion. The FY2017-FY2021 Capital Investment Plan, approved by
7171-455: The light rail concept was the "Shaker Heights Rapid Transit" which started in the 1920s, was renovated in 1980-81 and is now part of RTA Rapid Transit . Many original tram and streetcar systems in the United Kingdom , United States , and elsewhere were decommissioned starting in the 1950s as subsidies for the car increased. Britain abandoned its tram systems, except for Blackpool , with
7272-495: The line runs through the center of the Cedar Grove Cemetery. As of July 2023, the line operates on 6 minute headways at weekday peak hours and 12–13 minute headways at other times. On March 20, 1979, three trolleys collided between Central Avenue and Valley Road stations. The first two trolleys had stopped to avoid a police car, which had become stuck on the tracks while the officer was investigating teenagers drinking near
7373-466: The line to five operable streetcars. The rolling stock consists of rebuilt PCC streetcars , which were formerly part of a fleet shared with the Green Line . The historic rolling stock is retained largely because the line, built for 1920s streetcars, would have to be substantially rebuilt to accommodate the heavier modern cars used on the Green Line. In order to clear the line of snow, the MBTA maintains
7474-405: The line's ability to operate during snowstorms, rebuild all eight stations, replace track and signals, and repair bridges. Rehabilitation of the existing fleet is happening at the same time, to extend trolley life a few more years until LRVs arrive. By 2023, work was underway on 15% design. The 2007-built loop at Ashmont station will be removed as part of the project. The line begins and ends within
7575-538: The line. A third trolley was unable to stop in time while approaching around a blind curve; it slammed into the first two trolleys, causing injuries, but no deaths. Using funding from the American Recovery and Reinvestment Act of 2009 , the MBTA conducted a pilot test of technology similar to a collision avoidance system in an automobile, using radar and increasingly fast beeping to warn train operators of obstacles ahead. Like positive train control , it would stop
7676-465: The old and new systems. Since the 1980s, Portland, Oregon , has built all three types of system: a high-capacity light rail system in dedicated lanes and rights-of-way, a low-capacity streetcar system integrated with street traffic, and an aerial tram system . The opposite phrase heavy rail , used for higher-capacity, higher-speed systems, also avoids some incompatibilities in terminology between British and American English, for instance in comparing
7777-487: The previous junction. This situation is most prevalent either where the junction designer has placed the on-slip to the road before the off-slip at a junction (for example, the cloverleaf interchange ), or in urban areas with many close-spaced junctions. The ring road of Coventry , England , is a notorious example, as are parts of the southern M25, the London orbital motorway , the M6/M5 junction north-west of Birmingham , and
7878-540: The required clearance height can be reduced significantly compared to conventional light rail vehicles. Reference speed from major light rail systems, including station stop time, is shown below. However, low top speed is not always a differentiating characteristic between light rail and other systems. For example, the Siemens S70 LRVs used in the Houston METRORail and other North American LRT systems have
7979-432: The right-of-way that is often separated from other traffic for part or much of the way. Light rail vehicles are typically driven electrically with power being drawn from an overhead electric line via a trolley [pole] or a pantograph ; driven by an operator onboard the vehicle; and may have either high platform loading or low-level boarding using steps." However, some diesel-powered transit is designated light rail, such as
8080-415: The road network might lead to increased travel times ( Downs–Thomson paradox , Braess's paradox ). 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 rights-of-way , not much more than two car lanes wide for a double track system. They can often be run through existing city streets and parks , or placed in
8181-401: 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 higher and will increase when the traffic level increases. And because the capacity of a light rail system is higher than that of
8282-540: The safe operation of high-speed lines. The construction of new level crossings is generally not permitted, especially for high speed railway lines and level crossings are increasingly less common due to the increase of both road and rail traffic. Efforts to remove level crossings are done in the UK by Network Rail and in Melbourne as part of the Level Crossing Removal Project . The London Extension of
8383-662: The same as the German term for the mode, Straßenbahn (meaning "street railway"). A further difference arose because, while Britain abandoned all of its trams after World War II except in Blackpool , eight major North American cities ( Toronto , Boston , Philadelphia , San Francisco , Pittsburgh , Newark , Cleveland , and New Orleans ) continued to operate large streetcar systems. When these cities upgraded to new technology, they called it light rail to differentiate it from their existing streetcars since some continued to operate both
8484-609: The same gauge, the most complicated grade-separation railpoint is found at Liubotyn in Ukraine . Footbridges and subways (called underpasses in North America as well as in the United Kingdom when referring to roads) may be employed to allow pedestrians and cyclists to cross busy or fast streets. They are often used over and under motorways since at grade pedestrian crossings are generally not permitted. Same can be said for railways. Though introduced to Central Park in New York City in
8585-408: The standard gauge is that standard railway maintenance equipment can be used on it, rather than custom-built machinery. Using standard gauges also allows light rail vehicles to be conveniently moved around using the same tracks as freight railways. Additionally, wider gauges (e.g. standard gauge) provide more floor clearance on low-floor trams that have constricted pedestrian areas at the wheels, which
8686-551: The system was a success with the public, gaining up to 190,000 passengers per day. Automatic train operation is employed on light rail networks, tracking the position and speed of a train and hence adjusting its movement for safety and efficiency. One line of light rail (requires 7.6 m, 25' right of way) has a theoretical capacity of up to 8 times more than one 3.7 m (12 foot) lane on a freeway, excluding busses, during peak times. Roads have ultimate capacity limits that can be determined by traffic engineering , and usually experience
8787-400: The tightly grouped nest of flying junctions to the north of Clapham Junction railway station —although technically a combination of many junctions—handle more than 4,000 trains per day (about one train every 15 seconds). Virtually all major railway lines no longer cross (forming an 'X' shape ) at flat level (although many diverge - i.e. 'Y' shape). On almost all high-speed railway lines,
8888-464: The tracks of snow, but the PCC cars' traction motors would short out if they were used for that purpose. The current set of PCC cars are "Wartime" PCCs, built by Pullman-Standard in 1945–46. They have been in continuous revenue service in Boston since their construction, although PCC cars were not assigned to the Mattapan Line until 1955. The current fleet was rebuilt as part of a systemwide PCC rebuild program in 1978–83, and again in 1999–2005. During
8989-537: The traffic already on the roundabout wishing to use the M6 Westbound on-slip. This is as a result of the slip roads on the west side of the junction connecting to the roundabout on the inside of the eastern arc rather than the outside of the western arc as is normal. The two slip-roads are connected by a single lane on the inside of the roundabout, which traffic wishing to use the Westbound on-slip must join, and traffic from
9090-487: The train if the driver did not take action to avoid an impending collision. If successful, the system would be considered for deployment on the Green Line , where multiple collisions had occurred in recent years. On November 26, 2014, an out-of-service streetcar collided with an in-service streetcar near Cedar Grove. Seven people were injured. On December 29, 2017, a collision between two in-service streetcars caused 17 injuries. The accident, caused by operator error, reduced
9191-450: The trams, making it safe on city streets. Several systems in Europe and a few recently opened systems in North America use diesel -powered trains. When electric streetcars were introduced in the late 19th century, conduit current collection was one of the first ways of supplying power, but it proved to be much more expensive, complicated, and trouble-prone than overhead wires . When electric street railways became ubiquitous, conduit power
9292-455: The vast majority of light rail systems. This avoids the danger potentially presented by an electrified third rail . The Docklands Light Railway 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 Bordeaux , France, use a special third-rail configuration where the power is only switched on beneath
9393-434: 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. The BART railcar in the following chart is not generally considered to be
9494-657: Was approved on March 23, 1923. Steam trains were discontinued in 1927 and the line was closed for two years while it was modified for streetcars. There was a debate at that time whether or not to continue subway trains from Boston to Ashmont onwards to Mattapan, but the cost of full-scale subway service was apparently too high for the Boston Elevated Railway which then operated it. The line opened from Ashmont to Milton on August 26, 1929, and from Milton to Mattapan on December 21, 1929. Infill stations were opened at Capen Street in September 1930 and Butler on October 7, 1931. In 1966,
9595-513: Was cancelled, though the Mattapan line and the Ashmont branch were closed from June 20, 1981, to January 16, 1982, for track replacement and tunnel repairs. The line's longest shutdown took place from June 24, 2006, to December 22, 2007, with shuttle buses replacing streetcar service. A new elevated loop was built at Ashmont – part of a major reconstruction of the station – and the aging canopy at Mattapan
9696-527: Was coined in 1972 by the U.S. Urban Mass Transportation Administration (UMTA; the precursor to the Federal Transit Administration ) to describe new streetcar transformations that were taking place in Europe and the United States. In Germany, the term Stadtbahn (to be distinguished from S-Bahn , which stands for Stadtschnellbahn ) was used to describe the concept, and many in UMTA wanted to adopt
9797-502: Was coined in 1972 in the United States as an English equivalent for the German word Stadtbahn , meaning "city railway". Different definitions exist in some countries, but in the United States, light rail operates primarily along exclusive rights-of-way and uses either individual tramcars or multiple units coupled together, with a lower capacity and speed than a long heavy rail passenger train or rapid transit system. Narrowly defined, light rail transit uses rolling stock that
9898-662: Was introduced in North America in 1972 to describe this new concept of rail transportation. Prior to that time the abbreviation "LRT" was used for " Light Rapid Transit " and " Light Rail Rapid Transit ". The first of the new light rail systems in North America began operation in 1978 when the Canadian city of Edmonton, Alberta , adopted the German Siemens-Duewag U2 system, followed three years later by Calgary, Alberta , and San Diego, California . The concept proved popular, with there now being numerous light rail systems in
9999-504: Was replaced. The intermediate stations were also rebuilt; all stations except Valley Road were made accessible. Buses again replaced service on the line from October 14–29, 2023, to allow for track work. The MBTA launched the Mattapan Line Transformation project in 2019, though it was largely inactive until 2022. The project aims to replace the PCC trolleys with light rail vehicles as the Green Line fleet turns over, restore
10100-610: Was the Gross-Lichterfelde tramway in Lichterfelde near Berlin in Germany, which opened in 1881. It was built by Werner von Siemens who contacted Pirotsky. It initially drew current from the rails, with overhead wire being installed in 1883. The first interurban to emerge in the United States was the Newark and Granville Street Railway in Ohio, which opened in 1889. An early example of
10201-517: 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, D.C. Third rail technology was investigated for use on the Gold Coast of Australia for the G:link light rail, though power from overhead lines was ultimately utilized for that system. In
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