1.
People mover
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A people mover or automated people mover is a type of grade-separated mass transit system. The term was applied to three different systems, developed roughly at the same time. One was Skybus, a mass transit system prototyped by the Westinghouse Electric Corporation beginning in 1964. The second, alternately called the People Mover and Minirail, opened in Montreal at Expo 67, finally the last, called PeopleMover or WEDway PeopleMover, was an attraction that was originally presented by Goodyear Tire and Rubber Company and that opened at Disneyland in 1967. Now, however, the people mover is generic, and may use technologies such as monorail, duorail. Propulsion may involve conventional on-board electric motors, linear motors or cable traction, generally speaking, larger APMs are referred to by other names. The most generic is automated guideway transit, which encompasses any automated system regardless of size, some complex APMs deploy fleets of small vehicles over a track network with off-line stations, and supply near non-stop service to passengers. These taxi-like systems are usually referred to as personal rapid transit. Larger systems, with vehicles with 20 to 40 passengers, are referred to as group rapid transit. Other complex APMs have similar characteristics to mass transit systems, another term Light Metro is also applied to describe the system worldwide. One of the first automated systems for human transportation was the screw-driven Never-Stop-Railway, constructed for the British Empire Exhibition at Wembley, London in 1924. This railway consisted of 88 unmanned carriages, on a double track along the northern and eastern sides of the exhibition. The railway ran reliably for the two years of the exhibition, and was then dismantled, small sections of this track bed, and a nearby heavy rail track bed, have been proposed for reuse. if Goodyear had ever considered working on People Movers. He felt that with Goodyears ability to move materials in large quantities on conveyor belts they should consider moving batches of people. Four years of engineering design, development and testing led to a joint patent being issued for three types of people movers, named Speedwalk, Speedramp, and Carveyor, Goodyear would sell the concept and Stephens-Adamson would manufacture and install the components. A Speedwalk consisted of a conveyor belt riding on a series of rollers, or a flat slippery surface. The passengers would walk onto the belt and could stand or walk to the exit point and they were supported by a moving handrail. Customers were expected to include airport terminals, ballparks, train stations, today, several manufacturers produce similar units called moving walkways
2.
O'Hare International Airport
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It is the primary airport serving the Chicago metropolitan area, with Midway International Airport, about 10 miles closer to the Loop, serving as a secondary airport. It is operated by the City of Chicago Department of Aviation, OHare was the busiest airport in the world by number of takeoffs and landings in 2014, topping Hartsfield-Jackson Atlanta International Airport, however, it lost the title to Atlanta a year later. Until 1998, OHare was also the worlds busiest airport in number of passengers and it was surpassed mainly due to limits the federal government imposed on the airport to reduce flight delays. As of 2016, OHare is the sixth-busiest airport in the world by passenger traffic, the third-busiest airport in the United States, OHare also has eight runways, more than any major international airport. OHare is a hub for American Airlines and United Airlines, as well as a hub for regional carrier Air Choice One. OHare was voted the Best Airport in North America for 10 years by two sources, Readers of the U. S. Edition of Business Traveler Magazine and Global Traveler Magazine, in contrast, Travel and Leisure magazines 2009 Americas Favorite Cities ranked Chicagos Airport System the second-worst for delays, behind the New York City airport system. OHare accounts for nearly 20% of the flight cancellations and delays. OHare was constructed in 1942–43 as part of a plant for Douglas C-54s during World War II. The site was chosen for its proximity to the city and transportation, the two-million-square-foot factory needed easy access to the workforce of the nations then-second-largest city, as well as its extensive railroad infrastructure. Orchard Place was a small farming community. Douglas Companys contract ended in 1945 and though plans were proposed to build commercial aircraft, with the departure of Douglas, the airfield took the name of Orchard Field Airport, the source of its three-letter IATA code ORD. In 1945, the city of Chicago chose Orchard Field as the site for a facility to meet future aviation demands, Matthew Laflin Rockwell was the director of planning for the U. S. Army Corps of Engineers and responsible for the site selection and design. He was the great-grandson of Matthew Laflin, a founder and pioneer of Chicago, in 1949, the airport was renamed OHare International Airport to honor Edward OHare, the U. S. Navys first flying ace and Medal of Honor recipient in World War II. (This is similar to, sourced from McCoy Air Force Base, being used for todays Orlando International Airport, by the early 1950s Midway Airport, Chicagos main airport since 1931, was the worlds busiest airport and was too crowded despite multiple expansions. Midways runways were known to be too short for the planned first generation of jets, so the city of Chicago, traveling with him, LT Whitey Feightner was redirected to land at OHare. The runway had just been completed and was covered with peach baskets to prevent aircraft from landing until it was opened, LT Feightner was told to ignore the baskets and land on the new runway, and his F7U became the first aircraft to land there. OHare opened a $1 million Skymotive terminal for corporate aircraft in 1955, the April 1957 Official Airline Guide shows 10 weekday departures on United,9 on American,6 on Capital,3 Eastern,3 TWA,2 Delta,2 North Central, and 1 Braniff
3.
Chicago
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Chicago, officially the City of Chicago, is the third-most populous city in the United States. With over 2.7 million residents, it is the most populous city in the state of Illinois, and it is the county seat of Cook County. In 2012, Chicago was listed as a global city by the Globalization and World Cities Research Network. Chicago has the third-largest gross metropolitan product in the United States—about $640 billion according to 2015 estimates, the city has one of the worlds largest and most diversified economies with no single industry employing more than 14% of the workforce. In 2016, Chicago hosted over 54 million domestic and international visitors, landmarks in the city include Millennium Park, Navy Pier, the Magnificent Mile, Art Institute of Chicago, Museum Campus, the Willis Tower, Museum of Science and Industry, and Lincoln Park Zoo. Chicagos culture includes the arts, novels, film, theater, especially improvisational comedy. Chicago also has sports teams in each of the major professional leagues. The city has many nicknames, the best-known being the Windy City, the name Chicago is derived from a French rendering of the Native American word shikaakwa, known to botanists as Allium tricoccum, from the Miami-Illinois language. The first known reference to the site of the current city of Chicago as Checagou was by Robert de LaSalle around 1679 in a memoir, henri Joutel, in his journal of 1688, noted that the wild garlic, called chicagoua, grew abundantly in the area. In the mid-18th century, the area was inhabited by a Native American tribe known as the Potawatomi, the first known non-indigenous permanent settler in Chicago was Jean Baptiste Point du Sable. Du Sable was of African and French descent and arrived in the 1780s and he is commonly known as the Founder of Chicago. In 1803, the United States Army built Fort Dearborn, which was destroyed in 1812 in the Battle of Fort Dearborn, the Ottawa, Ojibwe, and Potawatomi tribes had ceded additional land to the United States in the 1816 Treaty of St. Louis. The Potawatomi were forcibly removed from their land after the Treaty of Chicago in 1833, on August 12,1833, the Town of Chicago was organized with a population of about 200. Within seven years it grew to more than 4,000 people, on June 15,1835, the first public land sales began with Edmund Dick Taylor as U. S. The City of Chicago was incorporated on Saturday, March 4,1837, as the site of the Chicago Portage, the city became an important transportation hub between the eastern and western United States. Chicagos first railway, Galena and Chicago Union Railroad, and the Illinois, the canal allowed steamboats and sailing ships on the Great Lakes to connect to the Mississippi River. A flourishing economy brought residents from rural communities and immigrants from abroad, manufacturing and retail and finance sectors became dominant, influencing the American economy. The Chicago Board of Trade listed the first ever standardized exchange traded forward contracts and these issues also helped propel another Illinoisan, Abraham Lincoln, to the national stage
4.
Illinois
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Illinois is a state in the midwestern region of the United States, achieving statehood in 1818. It is the 6th most populous state and 25th largest state in terms of land area, the word Illinois comes from a French rendering of a native Algonquin word. For decades, OHare International Airport has been ranked as one of the worlds busiest airports, Illinois has long had a reputation as a bellwether both in social and cultural terms and politics. With the War of 1812 Illinois growth slowed as both Native Americans and Canadian forces often raided the American Frontier, mineral finds and timber stands also had spurred immigration—by the 1810s, the Eastern U. S. Railroads arose and matured in the 1840s, and soon carried immigrants to new homes in Illinois, as well as being a resource to ship their commodity crops out to markets. Railroads freed most of the land of Illinois and other states from the tyranny of water transport. By 1900, the growth of jobs in the northern cities and coal mining in the central and southern areas attracted a new group of immigrants. Illinois was an important manufacturing center during both world wars, the Great Migration from the South established a large community of African Americans in Chicago, who created the citys famous jazz and blues cultures. Three U. S. presidents have been elected while living in Illinois, Abraham Lincoln, Ulysses S. Grant, additionally, Ronald Reagan, whose political career was based in California, was the only U. S. president born and raised in Illinois. Today, Illinois honors Lincoln with its official slogan, Land of Lincoln. The Abraham Lincoln Presidential Library and Museum is located in the capital of Springfield. Illinois is the spelling for the early French Catholic missionaries and explorers name for the Illinois Native Americans. American scholars previously thought the name Illinois meant man or men in the Miami-Illinois language and this etymology is not supported by the Illinois language, as the word for man is ireniwa and plural men is ireniwaki. The name Illiniwek has also said to mean tribe of superior men. The name Illinois derives from the Miami-Illinois verb irenwe·wa he speaks the regular way and this was taken into the Ojibwe language, perhaps in the Ottawa dialect, and modified into ilinwe·. The French borrowed these forms, changing the ending to spell it as -ois. The current spelling form, Illinois, began to appear in the early 1670s, the Illinois name for themselves, as attested in all three of the French missionary-period dictionaries of Illinois, was Inoka, of unknown meaning and unrelated to the other terms. American Indians of successive cultures lived along the waterways of the Illinois area for thousands of years before the arrival of Europeans, the Koster Site has been excavated and demonstrates 7,000 years of continuous habitation
5.
Track gauge
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In rail transport, track gauge is the spacing of the rails on a railway track and is measured between the inner faces of the load-bearing rails. All vehicles on a network must have running gear that is compatible with the track gauge, as the dominant parameter determining interoperability, it is still frequently used as a descriptor of a route or network. There is a distinction between the gauge and actual gauge at some locality, due to divergence of track components from the nominal. Railway engineers use a device, like a caliper, to measure the actual gauge, the nominal track gauge is the distance between the inner faces of the rails. In current practice, it is specified at a distance below the rail head as the inner faces of the rail head are not necessarily vertical. In some cases in the earliest days of railways, the company saw itself as an infrastructure provider only. Colloquially the wagons might be referred to as four-foot gauge wagons, say and this nominal value does not equate to the flange spacing, as some freedom is allowed for. An infrastructure manager might specify new or replacement track components at a variation from the nominal gauge for pragmatic reasons. Track is defined in old Imperial units or in universally accepted metric units or SI units, Imperial units were established in United Kingdom by The Weights and Measures Act of 1824. In addition, there are constraints, such as the load-carrying capacity of axles. Narrow gauge railways usually cost less to build because they are lighter in construction, using smaller cars and locomotives, as well as smaller bridges, smaller tunnels. Narrow gauge is often used in mountainous terrain, where the savings in civil engineering work can be substantial. Broader gauge railways are generally expensive to build and require wider curves. There is no single perfect gauge, because different environments and economic considerations come into play, a narrow gauge is superior if ones main considerations are economy and tight curvature. For direct, unimpeded routes with high traffic, a broad gauge may be preferable, the Standard, Russian, and 46 gauges are designed to strike a reasonable balance between these factors. In addition to the general trade-off, another important factor is standardization, once a standard has been chosen, and equipment, infrastructure, and training calibrated to that standard, conversion becomes difficult and expensive. This also makes it easier to adopt an existing standard than to invent a new one and this is true of many technologies, including railroad gauges. The reduced cost, greater efficiency, and greater economic opportunity offered by the use of a common standard explains why a number of gauges predominate worldwide
6.
Blue Line (CTA)
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The Blue Line, also known as the OHare-Congress Line and the West-Northwest Line, is a 26. It is the CTAs second busiest rail line, with an average of 186,796 passengers boarding each weekday in September 2012. The Blue Line and Red Line are the two routes of the Chicago L system to currently run 24 hours a day and is one of only six rapid transit rail systems in the United States to do so. The Blue Line is also one of two lines with more than one station with the same name, with the Green Line being the other. The Blue Line also has only three in-system transfers, contains a combination of both the oldest and newest portions of L tracks, and does not share tracks with any other L line. Before the adoption of color-coded names, the Blue Line was referred to as the West-Northwest Route or more commonly, the Congress and Douglas branches were renamed for their terminals, Forest Park and 54th/Cermak, when the current color naming system was adopted in 1993. Blue Line service on the Douglas Branch was discontinued in April 2008, the Blue Line is one of five L lines that run into Chicago suburbs, with the others being the Green, Purple, Pink, and Yellow lines. The most vintage components of the Blue Line began as part of the Metropolitan West Side Elevated Railroad in 1895, service on this section began on May 6,1895. The structure was completed from Damen Avenue to Logan Square on May 25,1895, an extension of service over the tracks of the Aurora, Elgin and Chicago Railroad to a new terminal at Desplaines Avenue was established on March 11,1905. A subsequent extension to Westchester opened on October 1,1926 and this was followed by still another addition when the Douglas Park Branch was placed in operation as far south as 18th Street on April 28,1896. The Douglas Park branch was cut back to 54th Avenue in Cicero. The Metropolitan West Side Elevated began service onto the Loop on October 11,1897, with opening of the Dearborn Subway, the old elevated alignment between Evergreen and Marshfield Avenues was decommissioned, used only for moving out-of-service rail cars. The new line connected with the Milwaukee-Dearborn Subway at the Chicago River, a five-mile extension of the route via the short subway connection and the Kennedy Expressway median from Logan Square to Jefferson Park opened on February 1,1970. It was also built by the City of Chicago using federal money, in March 1980, construction began on the OHare Airport extension of the Kennedy route between Jefferson Park and the airport. The first section between Jefferson Park and Rosemont was placed in service on February 27,1983, and the section to OHare on September 3,1984. On February 21,1993, the CTA adopted a color-coded naming system to the transit system. Congress service was doubled through much of the day since service frequency from OHare required shorter headways than what would have been left. On September 10,2001, the CTA began a reconstruction of the Douglas Branch to repair its aging stations
7.
Platform screen doors
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Platform screen doors and platform edge doors at train or subway stations screen the platform from the train. They are a new addition to many metro systems around the world. They are widely used in newer Asian and European metro systems, the first stations in the world with platform screen doors are ten stations in the Saint Petersburg Metros Line 2 that opened between 1961 and 1972. The platform doors are actually openings in the wall, which support the ceiling of the platform. The track tunnels adjoining the ten island platforms were built with tunnel boring machines. Usually, TBMs bore the tunnels between stations, while the station vaults are dug out manually and contain both the tracks and the platform. These openings were covered with doors in order to prevent people from falling into the gaps between the walls. In 1987, the Singapore MRT was the first system in the world to install glass PSDs based on safety reasons, although the terms are often used interchangeably, platform screen doors can refer to both full-height and half-height barriers. The half-screen doors are only half of the height of the full-screen doors. These two types of screen doors are presently the main types in the world. These doors help to, Prevent accidental falls off the platform onto the track area, suicide attempts. Improve climate control within the station, improve security — access to the tracks and tunnels is restricted. Lower costs — eliminate the need for motormen or conductors when used in conjunction with Automatic Train Operation, Prevent litter build up on the track, which can be a fire risk. Improve the sound quality of platform announcements, as noise from the tunnels. Their primary disadvantage is their cost, installing a system typically costs several million USD per station and they also impede natural ventilation, increasing climate control costs. The doors also pose their own safety risks, the primary risk is that people may be trapped between the platform doors and the train carriage, and be subsequently crushed when the train begins to move. Cases of this happening are rare, and may depend upon door design, like full-height platform screen doors, these platform gates slide open or close simultaneously with the train doors. Half-height platform gates are cheaper to install platform screen doors
8.
Metra
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Metra is a commuter railroad in the Chicago metropolitan area. The railroad operates 241 stations on 11 different rail lines and it is the fourth busiest commuter rail system in the United States by ridership and the largest and busiest commuter rail system outside the New York City metropolitan area. There were 83.4 million passenger rides in 2014, up 1. 3% from the previous year, the estimated busiest day for Metra ridership occurred on Nov.4, 2016—the day of the Chicago Cubs 2016 World Series victory rally. Using Chicagos rail infrastructure, much of which was created in the 19th century, the Illinois General Assembly established the RTA, Metras creation was a result of the anticipated failure of commuter service operated and owned by various private railroad companies in the 1970s. Freight rail companies still operate some routes, however, these operations are guided by contracted service agreements, Metra owns all rolling stock and is responsible for all stations along with the respective municipalities. Since its inception, Metra has directed more than $5 billion into the rail system of the Chicago metropolitan area. Since its founding in the 19th century, Chicago has been a major Midwestern hub in the North American rail network and it has more trackage radiating in more directions than any other city in North America. Railroads set up their headquarters in the city and Chicago became a center for building cars, passenger cars. By the 1930s Chicago had the worlds largest public transportation system, by the mid-1970s, the commuter lines faced an uncertain future. The Burlington Northern, Milwaukee Road, Chicago and North Western, to provide stability to the commuter rail system, the Illinois General Assembly formed the Regional Transportation Authority in 1974. Its purpose was to fund and plan the Chicago regions public transportation, in the beginning the Regional Transportation Authority commuter train fleet consisted of second-hand equipment, until 1976 when the first order of new EMD F40PH locomotives arrived. That F40PH fleet is still in service today, less than a decade later the Regional Transportation Authority was already suffering from ongoing financial problems. In 1983 the Illinois Legislature reorganized the agency and that reorganization left the Regional Transportation Authority in charge of day-to-day operations of all bus, heavy rail and commuter rail services throughout the Chicago metropolitan area. It was also responsible for directing fare and service levels, setting up budgets, finding sources for capital investment, due to the broad range of responsibilities entrusted with the Regional Transportation Authority, the Commuter Rail Service Board was created in 1984. It was renamed Metra in July 1985, the newly reorganized Metra service helped to bring a single identity to the many infrastructure components serviced by the Regional Transportation Authoritys commuter rail system. Metras operating arm, the Northeast Illinois Regional Commuter Railroad Corporation, was created as a separate subsidiary which operates seven Metra owned routes. Contracts were set up with the Union Pacific and BNSF railroads to operate four other Metra routes, while Metra owns all rolling stock and is responsible for most stations on those routes, the freight carriers use their own employees and control the right-of-way for those routes. In keeping with Metras purpose to provide an identity for commuter rail in the region
9.
Chicago Union Station
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Chicago Union Station is a major railroad station that opened in 1925 in Chicago, Illinois, replacing an earlier station built in 1881. It is the only remaining intercity rail terminal in Chicago, as well as being the primary terminal for commuter trains. The station stands on the west side of the Chicago River between West Adams Street and West Jackson Boulevard, just outside the Chicago Loop, including approach and storage tracks, it is about nine and a half city blocks in size. Its facilities are underground, buried beneath streets and skyscrapers. Chicago Union Station is the third-busiest rail terminal in the United States, after Grand Central Terminal and it is Amtraks overall fourth-busiest station. It handles approximately 120,000 passengers on a weekday and is one of Chicago’s most iconic structures, reflecting the city’s strong architectural heritage. In addition to standing out architecturally, Union Station has features that reflect its commitment to sustainability, in 2011, its lighting system was replaced with more energy-efficient light bulbs and motion sensors, reducing the station’s carbon footprint by 4 million tons annually. Chicago Union Station was designated as one of America’s “Great Places” in 2012 by the American Planning Association. The “Great Places” program by APA highlights places streets, neighborhoods, and public spaces around America that exhibit “exemplary character, quality, and planning. ”These places are unique in their cultural and historical significance, sense of community, and vision. Other criteria include “architectural features, accessibility, functionality, and community involvement. ”Chicago Union Station is considered a “Great Public Space” by APA and these spaces are safe and inviting, well-maintained, and attractive, both visually and in functionality. In addition, local culture and history are reflected within the space, Union Station is laid out with a double stub-end configuration, with 10 tracks coming into the station from the north and 14 from the south. Because passenger trains do not pass through Union Station, all passengers traveling through Chicago must change trains to reach their final destination. There are 2 through tracks to allow out-of-service equipment moves between the north and south side, including one with a platform to allow extra long trains to board, between the north and south sides of the station is a passenger concourse. Passengers can walk through the concourse to get from any platform to any other without stairs or elevators, odd-numbered platforms are on the north half of the station, and even-numbered platforms on the south half. The north tracks are used by Amtrak for the Hiawatha Service and the Empire Builder, and by Metra for the Milwaukee District West, Milwaukee District North, the south tracks are used for all of the other Amtrak and Metra services. Two station management structures, one on side of the terminal, monitor train-to-track assignments. The concourse also has a level between platform and street level, containing a food court featuring local vendors as well as national chains. Located west of Canal Street, Union Stations headhouse occupies a city block
10.
France
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France, officially the French Republic, is a country with territory in western Europe and several overseas regions and territories. The European, or metropolitan, area of France extends from the Mediterranean Sea to the English Channel and the North Sea, Overseas France include French Guiana on the South American continent and several island territories in the Atlantic, Pacific and Indian oceans. France spans 643,801 square kilometres and had a population of almost 67 million people as of January 2017. It is a unitary republic with the capital in Paris. Other major urban centres include Marseille, Lyon, Lille, Nice, Toulouse, during the Iron Age, what is now metropolitan France was inhabited by the Gauls, a Celtic people. The area was annexed in 51 BC by Rome, which held Gaul until 486, France emerged as a major European power in the Late Middle Ages, with its victory in the Hundred Years War strengthening state-building and political centralisation. During the Renaissance, French culture flourished and a colonial empire was established. The 16th century was dominated by civil wars between Catholics and Protestants. France became Europes dominant cultural, political, and military power under Louis XIV, in the 19th century Napoleon took power and established the First French Empire, whose subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a succession of governments culminating with the establishment of the French Third Republic in 1870. Following liberation in 1944, a Fourth Republic was established and later dissolved in the course of the Algerian War, the Fifth Republic, led by Charles de Gaulle, was formed in 1958 and remains to this day. Algeria and nearly all the colonies became independent in the 1960s with minimal controversy and typically retained close economic. France has long been a centre of art, science. It hosts Europes fourth-largest number of cultural UNESCO World Heritage Sites and receives around 83 million foreign tourists annually, France is a developed country with the worlds sixth-largest economy by nominal GDP and ninth-largest by purchasing power parity. In terms of household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, France remains a great power in the world, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a member state of the European Union and the Eurozone. It is also a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, originally applied to the whole Frankish Empire, the name France comes from the Latin Francia, or country of the Franks
11.
Rubber-tyred metro
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A rubber-tyred metro is a form of rapid transit system that uses a mix of road and rail technology. Most rubber-tyred trains are purpose-built and designed for the system on which they operate, guided buses are sometimes referred to as trams on tyres, and compared to rubber-tyred metros. The first idea for rubber-tyred railway vehicles was the work of Scotsman Robert William Thomson, in his patent of 1846 he describes his Aerial Wheels as being equally suitable for, the ground or rail or track on which they run. During the World War II German occupation of Paris, the Metro system was used to capacity, at the end of the war, the system was so worn out that thought was given as to how to renovate it. Rubber-tyred metro technology was first applied to the Paris Métro, developed by Michelin, who provided the tyres and guidance system, in collaboration with Renault, who provided the vehicles. Starting in 1951, a vehicle, the MP51. Line 11 Châtelet - Mairie des Lilas was the first line to be converted, in 1956, finally, Line 6 Charles de Gaulle - Étoile - Nation was converted in 1974 to cut down train noise on its many elevated sections. The first completely rubber-tyred metro system was built in Montreal, Canada, santiago Metro and Mexico City Metro are based on Paris Métro rubber-tyred trains. Paris Metro Line 14 was automated from its beginning, and Line 1 was converted to automatic in 2007-2011, the first automated rubber-tyred system opened in Kobe, Japan, in February 1981. It is the Portliner linking Sanomiya railway station with Port Island, the vehicle is in the form of electric multiple unit, with power supplied by both, of the guide bars, which thus also serves as the third rail. The return current passes through a return shoe to the top of one, the type of guideway used on a system varies between networks. Two parallel roll ways, each the width of a tyre, are used, either of concrete, concrete slab, H-Shape hot rolled steel, or flat steel. As on a railway, the driver does not have to steer, the Sapporo system is an exception as it uses a central guide rail only. The VAL system used in Lille and Toulouse has conventional track between the guide bars, in Paris these rails were also used to enable mixed traffic with rubber-tyred and steel-wheeled trains using the same track, particularly during conversion from normal railway track. Other systems have other sorts of flat tyre compensation and switching methods, rubber-tyres have higher rolling resistance when compared to traditional steel wheels, which leads to some advantages and disadvantages. Compared to steel wheel on rail, the advantages of rubber-tyred metro systems are. Shorter braking distances, allowing trains to be signalled closer together, quieter rides in open air due to use rubber-tyre. Greatly reduced rail wear with resulting reduced costs of those parts
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