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Gridlock
Gridlock is a form of traffic congestion where continuous queues of vehicles block an entire network of intersecting streets, bringing traffic in all directions to a complete standstill. The term originates from a situation possible in a grid plan where intersections are blocked, preventing vehicles from either moving forwards through the intersection or backing up to an upstream intersection. The term ''gridlock'' is also used incorrectly to describe high traffic congestion with minimal flow (which is simply a traffic jam), where a blocked grid system is not involved. By extension, the term has been applied to situations in other fields where flow is stalled by excess demand, or in which competing interests prevent progress. Cause Traditional gridlock is caused by cars entering an intersection on a green light without enough room on the other side of the intersection ''at the time of entering'' to go all the way through. This can lead to the car being trapped in the inters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Congestion
Traffic congestion is a condition in transport that is characterized by slower speeds, longer trip times, and increased vehicular queueing. Traffic congestion on urban road networks has increased substantially since the 1950s, resulting in many of the roads becoming obsolete. When traffic demand is great enough that the interaction between vehicles slows the traffic stream, this results in congestion. While congestion is a possibility for any mode of transportation, this article will focus on automobile congestion on public roads. Mathematically, traffic is modeled as a flow through a fixed point on the route, analogously to fluid dynamics. As demand approaches the capacity of a road (or of the intersections along the road), extreme traffic congestion sets in. When vehicles are fully stopped for periods of time, this is known as a traffic jam or (informally) a traffic snarl-up or a tailback. Drivers can become frustrated and engage in road rage. Drivers and driver-focused r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sam Schwartz
Samuel I. Schwartz, also known as Gridlock Sam, is an American transportation engineer, formerly the New York City Traffic Commissioner, notable for popularizing the phrase "gridlock". Life and career After graduating from Brooklyn Technical High School in 1965, Schwartz was educated at Brooklyn College (BS Physics) and the University of Pennsylvania (MSCE), and first worked as a New York City cabbie before being hired by the City of New York in 1971. He served as NYC Traffic Commissioner from 1982 to 1986, and when the traffic department became subsumed by the Department of Transportation he held the second-in-command post of First Deputy Commissioner and Chief Engineer from 1986-1990. While employed with the city, he attempted to introduce bicycle lanes and public plazas. They were vetoed at the last minute by then-mayor John Lindsay. He earned the nickname Gridlock Sam during the 1980 transit strike when he developed a series of transportation contingency plans, called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Box Junction
A box junction is a road traffic control measure designed to prevent congestion and gridlock at junctions. The surface of the junction is typically marked with a yellow criss-cross grid of diagonal painted lines (or only two lines crossing each other in the box), and vehicles may not enter the area so marked unless their exit from the junction is clear, or they are intending to turn and are prevented from doing so by oncoming traffic, or other vehicles on the box waiting to turn. Box junctions were introduced in the UK during 1967, following a successful trial in London. Motor Cycle, 23 March 1967, p.378 ''More Box Junctions''. Accessed and added 2014-06-10 In both Ireland and the United Kingdom (where cars drive on the left), drivers may enter the box and wait when they want to turn right and are stopped from doing so only by oncoming traffic or by other vehicles waiting to turn right. Box junctions may be painted on other areas of roadway which must be kept free of queuing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Pollution
Air pollution is the presence of substances in the Atmosphere of Earth, air that are harmful to humans, other living beings or the environment. Pollutants can be Gas, gases like Ground-level ozone, ozone or nitrogen oxides or small particles like soot and dust. It affects both outdoor air and indoor air. Natural sources of air pollution include Wildfire, wildfires, Dust storm, dust storms, and Volcanic eruption, volcanic eruptions. Indoor air pollution is often Energy poverty and cooking, caused by the use of biomass (e.g. wood) for cooking and heating. Outdoor air pollution comes from some industrial processes, the burning of Fossil fuel, fossil fuels for electricity and transport, waste management and agriculture. Many of the contributors of local air pollution, especially the burning of fossil fuels, also cause greenhouse gas emissions that cause climate change, global warming. Air pollution causes around 7 or 8 million deaths each year. It is a significant risk factor for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roadway Air Dispersion Modeling
Roadway air dispersion modeling is the study of air pollutant transport from a roadway or other linear emitter. Computer models are required to conduct this analysis, because of the complex variables involved, including vehicle emissions, vehicle speed, meteorology, and terrain geometry. Line source dispersion has been studied since at least the 1960s, when the regulatory framework in the United States began requiring quantitative analysis of the air pollution consequences of major roadway and airport projects. By the early 1970s this subset of atmospheric dispersion models was being applied to real-world cases of highway planning, even including some controversial court cases. How the model works The basic concept of the roadway air dispersion model is to calculate air pollutant levels in the vicinity of a highway or arterial roadway by considering them as line sources. The model takes into account source characteristics such as traffic volume, vehicle speeds, truck mix, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Transport And Land Use
The ''Journal of Transport and Land Use'' is an open access peer-reviewed academic journal covering the interaction of transport and land use that was established in 2008. As of August 2011, it is the official journal of the World Society for Transport and Land Use Research. It is operated on a volunteer basis with institutional support from the Center for Transportation Studies and the Networks, Economics, and Urban Systems Research Group at the University of Minnesota, where it is published three times per year. The founding editor is David M. Levinson and the editor-in-chief since 2023 is Ying Song. Abstracting The journal is abstracted and indexed in RePEc and the Transportation Research Board The Transportation Research Board (TRB) is a division of the National Academies of Sciences, Engineering, and Medicine. TRB's mission is to mobilize expertise, experience, and knowledge to anticipate and solve complex transportation-related challe ... TRID database References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deadlock (computer Science)
In concurrent computing, deadlock is any situation in which no member of some group of entities can proceed because each waits for another member, including itself, to take action, such as sending a message or, more commonly, releasing a lock. Deadlocks are a common problem in multiprocessing systems, parallel computing, and distributed systems, because in these contexts systems often use software or hardware locks to arbitrate shared resources and implement process synchronization. In an operating system, a deadlock occurs when a process or thread enters a waiting state because a requested system resource is held by another waiting process, which in turn is waiting for another resource held by another waiting process. If a process remains indefinitely unable to change its state because resources requested by it are being used by another process that itself is waiting, then the system is said to be in a deadlock. In a communications system, deadlocks occur mainly due to loss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City Department Of Transportation
The New York City Department of Transportation (NYCDOT) is the agency of the government of New York City responsible for the management of much of New York City's transportation infrastructure. Ydanis Rodriguez is the Commissioner of the Department of Transportation, and was appointed by Mayor Eric Adams on January 1, 2022. Former Commissioners have included Polly Trottenberg, Janette Sadik-Khan, and Iris Weinshall. The NYCDOT has a training center in eastern Queens. Responsibilities The Department of Transportation's responsibilities include day-to-day maintenance of the city's streets, highways, bridges, sidewalks, street signs, traffic signals, and street lights. DOT supervises street resurfacing, pothole repair, parking meter installation and maintenance, and municipal parking facility management. DOT also operates the Staten Island Ferry. DOT is the exclusive provider of day-to-day operations and maintenance on state-maintained roads and highways in city limits, while major ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1980 New York City Transit Strike
A 1980 transit strike in New York City halted service on the New York City Transit Authority (a subsidiary of the Metropolitan Transportation Authority) for the first time since 1966. Around 33,000 members of Transport Workers Union (TWU) Local 100 walked off their jobs on April 1, 1980, in a strike with the goal of increasing the wage for contracted workers. All subway and bus lines in the five boroughs of New York City were brought to a complete standstill for twelve days. The strike was resolved on April 11. History The transit workers' contract was up for renewal in April 1980. Negotiations began on February 4, with the TWU initially demanding a 21-month contract with a 30% wage increase; they justified the hike by claiming that the cost of living had gone up 53% since the last contract negotiation, and their contract did not account for changes in the cost of living. The negotiations were extremely confrontational. The MTA got a court writ prohibiting the workers from strik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of the longest-running newspapers in the United States, the ''Times'' serves as one of the country's Newspaper of record, newspapers of record. , ''The New York Times'' had 9.13 million total and 8.83 million online subscribers, both by significant margins the List of newspapers in the United States, highest numbers for any newspaper in the United States; the total also included 296,330 print subscribers, making the ''Times'' the second-largest newspaper by print circulation in the United States, following ''The Wall Street Journal'', also based in New York City. ''The New York Times'' is published by the New York Times Company; since 1896, the company has been chaired by the Ochs-Sulzberger family, whose current chairman and the paper's publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
