Traffic congestion is a condition on any network as use increases shamsi tamara dhaka university Traffic congestion is a condition on any network as use increases and is characterized by slower speeds, longer trip times, and increased queuing. The most common example is for physical use of roads by vehicles. When traffic demand is great enough that the interaction between vehicles slows the speed of the traffic stream, congestion is incurred.
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 colloquially known as a traffic jam. What is traffic congestion: Traffic congestion is a condition on any network as use increases and is characterized by slower speeds, longer trip times, and increased queuing. The most common example is for physical use of roads by vehicles.
When traffic demand is great enough that the interaction between vehicles slows the speed of the traffic stream, congestion is incurred. 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 colloquially known as a traffic jam. ?Mathematical Theories: Some traffic engineers have attempted to apply the rules of fluid dynamics to traffic flow, likening it to the flow of a fluid in a pipe.
Congestion simulations and real-time observations have shown that in heavy but free flowing traffic, jams can arise spontaneously, triggered by minor events (“butterfly effects”), such as an abrupt steering maneuver by a single motorist. Traffic scientists liken such a situation to the sudden freezing of super cooled fluid. However, unlike a fluid, traffic flow is often affected by signals or other events at junctions that periodically affect the smooth flow of traffic. Alternative mathematical theories exist, such as Boris Kerner’s three-phase traffic theory (see also spatiotemporal reconstruction of traffic congestion).
Because of the poor correlation of theoretical models to actual observed traffic flows, transportation planners and highway engineers attempt to forecast traffic flow using empirical models. Their working traffic models typically use a combination of macro-, micro- and macroscopic features, and may add matrix entropy effects, by “platooning” groups of vehicles and by randomizing the flow patterns within individual segments of the network. These models are then typically calibrated by measuring actual traffic flows on the links in the network, and the baseline flows are adjusted accordingly.
A team of MIT mathematicians has developed a model that describes the formation of “phantom jams,” in which small disturbances (a driver hitting the brake too hard, or getting too close to another car) in heavy traffic can become amplified into a full-blown, self-sustaining traffic jam. Key to the study is the realization that the mathematics of such jams, which the researchers call “jamitons,” are strikingly similar to the equations that describe detonation waves produced by explosions, says Aslan Kasimov, lecturer in MIT’s Department of Mathematics.
That discovery enabled the team to solve traffic- jam equations that were first theorized in the 1950s. ?Lane flow equation : The relationship between lane flow (Q, vehicles per hour), maximum speed (V, kilometers per hour) and density (K, vehicles per kilometer) is ?Economic theories: Congested roads can be seen as an example of the tragedy of the commons. Because roads in most places are free at the point of usage, there is little financial incentive for drivers not to over-use them, up to the point where traffic collapses into a jam, when demand becomes limited by opportunity cost.
Privatization of highways and road pricing have both been proposed as measures that may reduce congestion through economic incentives and disincentives. Congestion can also happen due to non-recurring highway incidents, such as a crash or roadwork’s, which may reduce the road’s capacity below normal levels. Economist Anthony Downs argues that rush hour traffic congestion is inevitable because of the benefits of having a relatively standard work day. In a capitalist economy, goods can be allocated either by pricing (ability to pay) or by queuing (first-come first-serve); congestion is an example of the latter.
Instead of the traditional solution of making the “pipe” large enough to accommodate the total demand for peak-hour vehicle travel (a supply-side solution), either by widening roadways or increasing “flow pressure” via automated highway systems, Downs advocates greater use of road pricing to reduce congestion (a demand-side solution, effectively rationing demand), in turn plowing the revenues generated therefore into public transportation projects. A 2011 study in the The American Economic Review indicates that there may be a “fundamental law of road congestion. The researchers, from the University of Toronto and the London School of Economics, analyzed data from the U. S. Highway Performance and Monitoring System for 1983, 1993 and 2003, as well as information on population, employment, geography, transit, and political factors. They determined that the number of vehicle-kilometers traveled (VKT) increases in direct proportion to the available lane-kilometers of roadways. The implication is that building new roads and widening existing ones only results in additional traffic that continues to rise until peak congestion returns to the previous level. 6] How computers help reducing traffic jam: ?Map out some alternative routes with the help of computers: Look for at least two additional ways to can complete the commute with the help of computers. Ideally, we can come up with five (even if some of them are different by only one street). Online, many map sites offer alternate routes and “no highways” options. ?Check traffic reports before leaving: Traffic updates are available on the Internet. Once one hits the road, he should continue listening to traffic reports on internet.
Use Clear- flow if it is available for the city. Clear- flow technology is considered to be more innovative than other traffic features because it’s based on the analysis of several years’ worth of real-world traffic data.  and click on “get directions”. Enter the starting and ending address, and make sure checking off the “Use Clear- flow to route based on traffic” option. ?Use a GPS device with live traffic updates during our commute : These devices will usually cost at least $200,and some require an additional subscription cost.
A 2008 report by Consumer Reports suggests that the Garmin Nuvi 265T and Garmin Nuvi 265 WT provide the best value, although they do have text-based advertisements.  Other factors to consider are ease of use, screen size, and whether street names are spoken. ?Get traffic updates on our computers : •Use Twitter. Find out how people are tweeting about traffic in our city and have those alerts sent to our pc or I phone.. For example, updates with “@command city’s airport code will turn up tweets from people who are sharing traffic info on the Internet. •Rand McNally also offers traffic updates on our pc. We can also browse the web and check for live traffic updates on various websites, but this draws our attention away from the road and is not recommended. Even if we’re in a traffic jam, we might still bump into the person in front of us, or contribute to the jam by not moving ahead when a space opens up in front of us because we’re too busy looking at our phone. ?Automatic number plate recognition (ANPR) : automatic number plate recognition (ANPR) cameras, connected with computers manufactured by PIPs Technology, to record vehicles entering and exiting the zone.
Cameras can record number plates with a 90% accuracy rate through the technology. The majority of vehicles within the zone are captured on camera. The cameras take two still pictures in color and black and white and use infrared technology to identify the number plates. The camera network and other roadside equipment is managed largely automatically by an instating system developed by Roke Manor Research Ltd, which delivers number plates to the billing system. These identified numbers are checked against the list of payers overnight by computer.
In those cases when a number plate has not been recognized then they are checked manually those that have paid but have not been seen in the central zone are not refunded, and those that have not paid and are seen are fined. The registered keeper (The registered keeper is presumed to be the owner unless shown otherwise) of such a vehicle is looked up in a database provided by the Driver and Vehicle Licensing Agency (DVLA), based in Swansea. ?Advanced Traffic Management System (ATMS): A fully automated system, ATMS binds primary traffic data collected from Automatic Incident Detection (AID) ystem and Automatic Vehicle Location System (AVLS). The AID system detects traffic congestion on the roads while the AVLS provides real time travel database. The system also manages the Closed Circuit Television (CCTV) surveillance cameras to monitor traffic situation and congestions. In addition, ATMS updates real-time road condition messages on Variable Message Signs (VMS) boards along major roads. Information gathered on traffic situations and congestion will be sent to TMC for analysis and evaluation before being transformed into useful traffic information.
TMC operators will use this information to formulate traffic management strategies such as maximizing roadway capacity usage, reducing travel times and improving traffic safety. At the same time, ATIS will deliver this real-time traffic information to road users and commuters in the form of a congestion map, travel speed map and incident map via the Internet (with support for wireless services) and Call Centre. Road users will get updated information on road conditions and congestion via Variable Message Signs (VMS) units located strategically along major roads.
Traffic jam is a huge problem in not only Dhaka city but also all around the world. Though we can’t prevent this but we can reduce this problem by using the above technology with the help of computers and their management information system. So we all should try to follow this technologies to make our life easier. The map of Dhaka city is shown in the next page- Map of Dhaka city References : •^ “Congestion charge cuts jams”. BBC News. 6 June 2003. Retrieved 23 November 2007 •Clement, Barrie (20 February 2007). “Congestion charge: Green lobby hails road-toll extension”.
The Independent (London: Independent News and Media Ltd). Retrieved 26 May 2004. •Andrew Downie (2008-04-21). “The World’s Worst Traffic Jams”. Time. Retrieved 2008-06-20 •”Glossary”, National Agenda for Motorcycle Safety (US Department of Transportation National Highway Traffic Safety Administration/Motorcycle Safety Foundation), retrieved 2010-09-18 • Md. Mirazul Islam (2011-08-14). “Traffic jam”. The Daily Star. Retrieved 2012-05-05. •(Portuguese) RAMOS, Camila Souza (interview with Beatriz Kushnir). ” “ditabranda A” e os interesses