Gridlock

Last updated
Gridlock on a network of two-way streets. The red cars are those causing the gridlock by stopping in the middle of the intersection. GridlockCorrected.png
Gridlock on a network of two-way streets. The red cars are those causing the gridlock by stopping in the middle of the intersection.

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". [1] 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.

Contents

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

Gridlock on Kaiser-Friedrich-Ring, Wiesbaden, Germany. Vehicles on three lanes blocking each others way. Gridlock (Wiesbaden, Germany).jpg
Gridlock on Kaiser-Friedrich-Ring, Wiesbaden, Germany. Vehicles on three lanes blocking each others way.
Traffic gridlock in Miami, Florida. Lights are green but backups fill all the space. 7th Street gridlock afternoon.jpg
Traffic gridlock in Miami, Florida. Lights are green but backups fill all the space.

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 intersection when the light turns green in the other direction. If the same situation occurs simultaneously in multiple intersections, these cars can be trapped in the intersections indefinitely.

In many jurisdictions, drivers are therefore prohibited from entering an intersection at a green light if there is no room for them to clear the intersection. If all drivers follow this rule, gridlock is impossible. [2]

Another type of gridlock can occur during traffic surges between highway on-ramps and off-ramps located within a quarter mile of each other. Traffic exiting the highway may back up and block the entering vehicles. Those entering vehicles in turn back up and block the exiting vehicles.

Gridlock is sometimes cited as an example of the prisoner's dilemma (from game theory). [3] Mutual cooperation among drivers would give the maximum benefit (prevention of gridlock), but this may not happen because of the desire to maximize one's own benefit (shortest travel time) given the uncertainty about the other drivers' commitment to equal cooperation.

Enforcement

New York City

Don't block the box sign NYCDOT SR-1258.svg
Don't block the box sign
Vehicles "blocking the box" in New York City New York City Gridlock.jpg
Vehicles "blocking the box" in New York City

In New York City, drivers who "block the box" are subject to a moving violation that comes with a US$90.00 penalty. Mayor Michael Bloomberg, noting that the ten-minute ticketing process actually contributes to overall traffic congestion, has asked the New York State Legislature to remove “blocking the box” from the moving violation category. This reclassification would give more traffic agents authority to write tickets and change the current ticketing procedure, which requires that the issuing officer physically stop the violating car in traffic. [4]

Virginia Beach, Virginia

In Virginia Beach, Virginia, roads around the oceanfront feature signs at every intersection stating "Don't Block the Box", and threatening a $200 fine.

Texas

In Austin, Texas, a "Don't Block the Box" initiative began in 2015. [5] [6] A similar program was piloted in San Antonio in 2017. [7]

Effects

The obvious effects are driver frustration and trip delay. Another effect in cities is exacerbated by the presence of urban street canyons, which effectively trap air pollution and increase air pollution exposures of motorists as well as the general urban population. Noise pollution can be aggravated by excessive starting and stopping noise of gridlocked facilities. [8]

Alleviating gridlock

To make a traffic system less susceptible to gridlock, a traffic metering system can be introduced. These systems determine the optimal number of vehicles allowed in a traffic system, and prevent any extra vehicles from entering. This can be done with traffic control devices, such as traffic lights or warning signs, or a better public transportation system. This type of system is used in Zurich, Switzerland. [9]

Etymology

According to The New York Times , the word gridlock was coined in New York City in the early 1970s. [10] The word appeared in an IEEE publication in 1971 in a different context. [11] The first appearances of gridlock in newspapers occurred during the 1980 New York City transit strike. The word is attributed to Sam Schwartz, who was then the chief traffic engineer for the New York City Department of Transportation at the time of the strike. [12] Schwartz said the word gridlock was used internally in his department during the 1970s, perhaps as early as 1971. [13] Writing up a memo of emergency recommendations for senior officials, he recalled the words of a colleague several years earlier who had been analyzing a proposal to close Broadway to vehicular traffic. His colleague gave the plan the thumbs-down, worrying that it would simply "lock up the grid". Schwartz was always struck by that image and titled his 1980 memo "Gridlock Prevention Plan". [14] In another interview Mr. Schwartz said that he coined the term in the mid 1970s with fellow traffic engineer, Roy Cottam, who "was a little paranoid and thought he would be blamed for gridlock and so he gave me all the credit". [15]

Historical events

China

The August 2010 traffic jam in the Beijing-Zhangjiakou highway in Hebei province, China, is considered the world's worst traffic jam ever, as traffic congestion stretched more than 100-kilometre (62 mi) from August 14 to the 26, including at least 11 days of total gridlock, with some drivers spending up to 5 days to cross this stretch of highway. [16] [17] [18] The event was caused by a combination of road works and thousands of coal trucks from Inner Mongolia’s coalfields that travel daily to Beijing. The New York Times has called this event the "Great Chinese Gridlock of 2010." [18] [19]

Brazil

According to Time magazine, São Paulo has the world's worst daily traffic jams. [20] On 23 May 2014, the worst traffic jam in history was registered, with 344-kilometre (214 mi) of traffic jam. [21]

France

For several years, the traffic jam that occurred in 1980 over a 175-kilometre (109 mi) long stretch of the French A6 Autoroute between Paris and Lyon was considered the world’s longest. [22]

See also

Related Research Articles

<span class="mw-page-title-main">Traffic</span> Phenomenon of movement by humans on foot or using vehicles

Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads/sidewalks) for travel and transportation.

<span class="mw-page-title-main">High-occupancy vehicle lane</span> Restricted traffic lane

A high-occupancy vehicle lane is a restricted traffic lane reserved for the exclusive use of vehicles with a driver and at least one passenger, including carpools, vanpools, and transit buses. These restrictions may be only imposed during peak travel times or may apply at all times. There are different types of lanes: temporary or permanent lanes with concrete barriers, two-directional or reversible lanes, and exclusive, concurrent, or contraflow lanes working in peak periods.

<span class="mw-page-title-main">Road pricing</span> Revenue generation for road infrastructure

Road pricing are direct charges levied for the use of roads, including road tolls, distance or time-based fees, congestion charges and charges designed to discourage the use of certain classes of vehicle, fuel sources or more polluting vehicles. These charges may be used primarily for revenue generation, usually for road infrastructure financing, or as a transportation demand management tool to reduce peak hour travel and the associated traffic congestion or other social and environmental negative externalities associated with road travel such as air pollution, greenhouse gas emissions, visual intrusion, noise pollution and road traffic collisions.

<span class="mw-page-title-main">Congestion pricing</span> System of surcharging users of public goods that are subject to congestion

Congestion pricing or congestion charges is a system of surcharging users of public goods that are subject to congestion through excess demand, such as through higher peak charges for use of bus services, electricity, metros, railways, telephones, and road pricing to reduce traffic congestion; airlines and shipping companies may be charged higher fees for slots at airports and through canals at busy times. Advocates claim this pricing strategy regulates demand, making it possible to manage congestion without increasing supply.

<span class="mw-page-title-main">Traffic congestion</span> Transport condition characterized by slower speed and high density

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. 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.

Level of service (LOS) is a qualitative measure used to relate the quality of motor vehicle traffic service. LOS is used to analyze roadways and intersections by categorizing traffic flow and assigning quality levels of traffic based on performance measure like vehicle speed, density, congestion, etc. In a more general sense, levels of service can apply to all services in asset management domain.

<span class="mw-page-title-main">Curb extension</span> Traffic calming measure

A curb extension is a traffic calming measure which widens the sidewalk for a short distance. This reduces the crossing distance and allows pedestrians and drivers to see each other when parked vehicles would otherwise block visibility. The practice of banning car parking near intersections is referred to as daylighting the intersection.

<span class="mw-page-title-main">Sam Schwartz</span>

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".

Vehicular communication systems are computer networks in which vehicles and roadside units are the communicating nodes, providing each other with information, such as safety warnings and traffic information. They can be effective in avoiding accidents and traffic congestion. Both types of nodes are dedicated short-range communications (DSRC) devices. DSRC works in 5.9 GHz band with bandwidth of 75 MHz and approximate range of 300 metres (980 ft). Vehicular communications is usually developed as a part of intelligent transportation systems (ITS).

<span class="mw-page-title-main">Lane splitting</span> Riding between lanes of traffic

Lane splitting is riding a bicycle or motorcycle between lanes or rows of slow moving or stopped traffic moving in the same direction. It is sometimes called whitelining, or stripe-riding. This allows riders to save time, bypassing traffic congestion, and may also be safer than stopping behind stationary vehicles.

<span class="mw-page-title-main">Congestion pricing in New York City</span> Traffic congestion fee in New York City

In New York City, a planned congestion pricing scheme will charge vehicles traveling into or within the central business district of Manhattan. First proposed in 2007, this disincentivizing fee to cut down on traffic congestion and pollution was approved and included in the 2019 New York state government budget by the New York State Legislature. As of February 2023, congestion pricing is scheduled to be implemented in the second quarter of 2024. When the congestion charge goes into effect, tolls will be collected electronically and will vary depending on the time of day, type of vehicle, and whether a vehicle has an E-ZPass toll transponder.

<span class="mw-page-title-main">Road space rationing</span> Travel demand management strategy

Road space rationing, also known as alternate-day travel, driving restriction and no-drive days, is a travel demand management strategy aimed to reduce the negative externalities generated by urban air pollution or peak urban travel demand in excess of available supply or road capacity, through artificially restricting demand by rationing the scarce common good road capacity, especially during the peak periods or during peak pollution events. This objective is achieved by restricting traffic access into an urban cordon area, city center (CBD), or district based upon the last digits of the license number on pre-established days and during certain periods, usually, the peak hours.

<span class="mw-page-title-main">Box junction</span> Type of junction designed to prevent congestion of traffic

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, 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.

<span class="mw-page-title-main">Road collision types</span> Overview of the various types of road traffic collision

Road traffic collisions generally fall into one of five common types:

<span class="mw-page-title-main">Transport in Bangkok</span>

Bangkok has 9.7 million automobiles and motorbikes, a number the government says is eight times more than can be properly accommodated on existing roads. And those numbers are increasing by 700 additional cars and 400 motorbikes every day. Charoen Krung Road, the first road to be built by Western techniques, was completed in 1864. Since then, the road network has expanded to accommodate the sprawling city's needs. Besides roads, Bangkok is served by several other transport systems. Bangkok's canals and ferries historically served as a major mode of transport, but they have long since been eclipsed by land traffic. A complex elevated expressway network and Tollway helps bring traffic into and out of the city centre, but Bangkok's rapid growth has put a large strain on infrastructure. By the late-1970s, Bangkok became known as "the city of traffic disaster". Although rail transport was introduced in 1893 and electric trams served the city from 1894 to 1968, it was only in 1999 that Bangkok's first rapid transit system began operation. Older public transport systems include an extensive bus network and boat services which still operate on the Chao Phraya and two canals. Taxis appear in the form of cars, motorcycles, and tuk-tuks.

<span class="mw-page-title-main">Traffic light control and coordination</span>

The normal function of traffic lights requires more than sight control and coordination to ensure that traffic and pedestrians move as smoothly, and safely as possible. A variety of different control systems are used to accomplish this, ranging from simple clockwork mechanisms to sophisticated computerized control and coordination systems that self-adjust to minimize delay to people using the junction.

<span class="mw-page-title-main">High-occupancy toll lane</span> Traffic lane or roadway on which high-occupancy vehicles are exempt from tolls

A high-occupancy toll lane is a type of traffic lane or roadway that is available to high-occupancy vehicles and other exempt vehicles without charge; other vehicles are required to pay a variable fee that is adjusted in response to demand. Unlike toll roads, drivers have an option to use general purpose lanes, on which a fee is not charged. Express toll lanes, which are less common, operate along similar lines, but do not exempt high-occupancy vehicles.

<span class="mw-page-title-main">Glossary of road transport terms</span>

Terminology related to road transport—the transport of passengers or goods on paved routes between places—is diverse, with variation between dialects of English. There may also be regional differences within a single country, and some terms differ based on the side of the road traffic drives on. This glossary is an alphabetical listing of road transport terms.

<span class="mw-page-title-main">Traffic in Metro Manila</span>

According to a "Global Driver Satisfaction" survey conducted by the navigation app Waze in 2015, Metro Manila had the "worst traffic on Southeast Asia". Emerson Carlos, MMDA assistant general manager for operation has mentioned that in 2015, motor vehicle registrations in Metro Manila peaked at around 2.5 million.

Traffic lights – devices positioned at road intersections, pedestrian crossings and other locations – control flows of traffic with social norms and laws created by the state. Traffic signals have to convey messages to drivers in a short period of time about constantly-changing road rules.

References

  1. ↑ "Gridlock" . Oxford English Dictionary. Oxford University Press. Retrieved 2011-05-03.
  2. ↑ Stringer, Scott M. Thinking outside the box: an analysis of Manhattan gridlock and spillback enforcement , Office of Manhattan Borough President, July 2006. [ dead link ]
  3. ↑ Heath, Joseph (1999). Normative economics Archived 2007-11-18 at the Wayback Machine , Chapter 2, Section 3. Retrieved 2007-03-19.
  4. ↑ "metro". Archived from the original on 2008-12-14. Retrieved 2007-10-26.
  5. ↑ "Some drivers feel trapped by 'Don't Block the Box' enforcement". KXAN. 25 April 2015. Archived from the original on 2015-07-03. Retrieved 2015-06-30.
  6. ↑ "More than 800 tickets issued for 'blocking the box'". KXAN. 21 April 2015. Archived from the original on 2015-07-03. Retrieved 2015-06-30.
  7. ↑ "Enforcement Begins Today for Don't Block the Box Pilot Program". City of San Antonio. Archived from the original on 2017-08-10. Retrieved 2017-05-04.
  8. ↑ C. Michael Hogan and Gary L. Latshaw, The relationship between highway planning and urban noise Archived 2007-05-18 at the Wayback Machine , :Proceedings of the ASCE, Urban Transportation Division specialty conference, May 21–23, 1973, Chicago, Illinois. by American Society of Civil Engineers. Urban Transportation Division
  9. ↑ Daganzo, Carlos F. (2007). "Urban gridlock: Macroscopic modeling and mitigation approaches". Transportation Research Part B: Methodological. 41 (1): 49–62. doi:10.1016/j.trb.2006.03.001.
  10. ↑ James Gleick (1988-05-08). "National Gridlock". New York Times . Archived from the original on 2015-05-25. Retrieved 2010-09-26.
  11. ↑ Letton, Winsor (1971). "Engineering in the Ocean Environment: A Method for Reducing Gridlock Errors". Google Books. Archived from the original on 2022-04-07. Retrieved 2020-09-14.
  12. ↑ Schwartz, Sam. About Gridlock Sam Archived 2005-08-24 at the Wayback Machine , GridlockSam.com. Retrieved 2007-03-19.
  13. ↑ Popik, Barry (July 21, 2004). Gridlock Archived 2006-10-28 at the Wayback Machine . Retrieved 2007-03-19.
  14. ↑ Kluger, Jeffrey: "Simplexity: Why Simple Things Become Complex (And How Complex Things Can Be Made Simple)", Hyperion, 2008, ISBN   978-1-4013-0301-3, pp.65-66.
  15. ↑ "Gridlock Sam Interview". SimCity 4. Archived from the original on 2011-03-18. Retrieved 2010-09-26.
  16. ↑ Leo Hickman (2010-08-23). "Welcome to the world's worst traffic jam". The Guardian . Archived from the original on 2015-10-17. Retrieved 2010-09-20.
  17. ↑ "The great crawl of China". The Economist. 2010-08-26. Archived from the original on 2010-10-22. Retrieved 2010-09-20.
  18. 1 2 Michael Wines (2010-08-27). "China's Growth Leads to Problems Down the Road". New York Times . Archived from the original on 2012-01-21. Retrieved 2010-09-20.
  19. ↑ Jonathan Watts (2010-08-24). "Gridlock is a way of life for Chinese". The Guardian . Archived from the original on 2013-09-15. Retrieved 2010-09-20.
  20. ↑ Andrew Downie (2008-04-21). "The World's Worst Traffic Jams". Time. Archived from the original on April 23, 2008. Retrieved 2008-06-20.
  21. ↑ "São Paulo sofre engarrafamento recorde de 344 quilômetros". Archived from the original on 2018-09-20. Retrieved 2018-03-31.
  22. ↑ Steve English. "From Horses to Horsepower: A Cavalcade of Interesting Automotive Facts". CAA Magazine. Archived from the original on 2010-06-08. Retrieved 2010-09-26.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.