2.1 IntroductionTraffic lights, or traffic signals, arelocated on most major corners in cities and towns around the world. The red,yellow and green lights let us know when it is safe to drive through theintersection and when to walk across the street as well as when to stop and letother drivers, bikers, and pedestrianstake their turns to continue their way.
2.2 History of Traffic SignalsHowever, onlyone month later, a police officer controlling the signal was badly injured whena leak in a gas main caused one of the lights to explode in his face. Theproject was declared a public health hazard and immediately dropped.The firstsignal lighting could be attributed to the use of campfires and flamingmarkings by prehistoric man to guide fishermen back to their tribes. There arehistorical references to regularly maintained traffic lights on towers datingback to 2600 years ago.
The most famous of these early structures, and probablythe tallest tower ever housing a traffic light, was the Pharos of Alexandria,Egypt. Built around 230 B.C., this structure has dominated some 400 feet in theair.
He survived two civilizations and survived the Roman Empire by ninecenturies. This marine lighthouse was truly a wonder of the world in its time.With respect to land transport, you have to look at the railways, where thesignaling lights have been well established. As early as 1857, lanternssuspended from a crossbar gave the railwaymena signal of blockage visible both at night and during the day.
In 1905, blocksignals were mostly semaphores with colored disks transmitting light from oillamps at night. Regarding the control or direction of road traffic by coloredfires, Britain probably saw for the first time what we now consider to betraffic lights. A native of Bradford, England, who was a mill worker much morethan a hundred years ago, seems to have had the idea of ??controlling trafficby means of colored lights. He built a control device using oil lamps that werealternately revealed and concealed by means of a shutter. Like many otherserious inventors, before and after his time, he sought to inform thegovernment of the administration of his ingenious device and what he would do.Officials remained convinced, however, that the police should control traffic,and the disappointed inventor walked back and forth to his Bradford factory tostay in the dark. It was up to a railway signal manufacturer company tosuccessfully build the world’s first traffic light using colored lights, inresponse to a suggestion made in 1866 by a select committee in Londonrecommending the adoption of railway equipment.
In mid-December 1868, a”beautiful” semaphore was installed at the intersection of George andBridge Streets, near the Houses of Parliament, to protect members of theparliament who had to negotiate traffic flows. This semaphore was 22 feet talland had the appearance of a hydra. Crowned with a gas light for visibility, thesemaphore arms when extended in a horizontal position meant”stopping”. Then lowered to a “falling” angle of 45 ‘themessage “attention”. At night, a green light was used with the”attention” position and a red light with the “stop”position. Richard Alayne, the policecommissioner of London, explained the semaphore’s meaning by a proclamation.CharlesJ. Reading, a municipal electrician in Salt Lake City, Utah, in 1916 or 1917,installed a signal of his own design (built by Mr.
Carter, a local tinsmith)that featured red and green lenses in four directions. It consisted of a sheetmetal construction, it was circular in shape and about 20 inches in diameter,and it had eight standard railway signaling lenses, about 8 inches in diameter.It was installed in the middle of theintersection and was controlled by a policeman in a corner.InDecember 1920, the use of all three traffic signals (green, yellow and red)were used for the first time following an installation in Michigan and Woodwardavenues in Detroit. The signals interpreted “go, clear the intersection andstop” for the green, yellow and red signals respectively. Thefirst interconnected traffic light system was installed in Salt Lake City in1917, with six connected intersections controlled simultaneously from a manualswitch.
Automatic Control of Interconnected Traffic Lights was introduced inMarch 1922 in Houston, Texas2.3 Competing PatentsFollowing theaccident, about four decades passed before traffic signals began to grow inpopularity again, mainly in the United States as more automobiles hit the road.The early 1900s saw several patents being filed, each with a differentinnovation to the basic idea.In 1910, Ernest Sirrine, anAmerican inventor, introduced an automatically controlled traffic signal inChicago. His traffic signal used two non-illuminated display arms arranged as across that rotated on an axis, according to Inventor Spot. The signs said “stop” and”proceed.”The first electric traffic light using red and greenlights was invented in 1912 by Lester Farnsworth Wire, a police officer in Salt LakeCity, Utah, according to Family Search. Wire’s traffic signal resembled afour-sided bird-house mounted on a tall pole.
It was placed in the middle of anintersection and was powered by overhead trolley wires. A police officer had tomanually switch the direction of the lights. However, the credit for the “first electrictraffic signal” usually goes to James Hoge. A systembased on his design was installed on Aug.
5, 1914, in Cleveland. Hoge receiveda patent for the system in 1918. (He had filed his application in 1913.) Hoge’straffic signal used the alternating illuminated words “stop” and”move” installed on a single post on each of the four corners of anintersection. The system was wired such that police and fire departments couldadjust the rhythm of the lights in case of an emergency.William Ghiglieri of San Francisco patented thefirst automatic traffic signal that used red and green lights in 1917.Ghiglieri’s design had the option of being either automatic or manual. Then in 1920, William Potts, a Detroit police officer, developedseveral automatic traffic light systems, including the first three-colorsignal, which added a yellow “caution” light.
In 1923, Garrett Morgan patentedan electric automatic traffic signal. Morgan was the first African-American toown a car in Cleveland. He also invented the gas mask. Morgan’s design used aT-shaped pole unit with three positions. Besides “Stop” and”Go,” the system also first stopped traffic in all directions to givedrivers time to stop or get through the intersection. Another benefit ofMorgan’s design was that it could be produced inexpensively, thus increasingthe number of signals that could be installed.
Morgan sold the rights to histraffic signal to General Electric for $40,000.The first electric traffic light in Europe wasinstalled in 1924 at Potsdamer Platz in Berlin, according to Marcus Welz,CEO of Siemens ITS (Intelligent Traffic Systems) US. The five-sided trafficlight was mounted on a tower and was primarily manual with some automation,which only required a single police officer to manage. A replica now standsnearby and is a popular tourist attraction.Pedestrian signals began to be included in traffic signals in the 1930s, according tothe U.S. Department of Transportation.
A “Walk/Don’tWalk” signal was first tested in New York in 1934. It even used an uprightpalm to indicate “Stop.”John S. Allen, an American inventor, filed one of theearliest patents in 1947 for a dedicated pedestrian traffic signal.
Allen’sdesign had the pedestrian signal mounted at curb level. Allen also proposedthat the signals could contain advertisements. In his application, he explainedthat the words “Stop” and “Go” could be followed by theword “for,” which in turn would be followed by a brand name. 12.4 Improving safety andefficiencyTraffic signals continue to improve. Many traffic signals are”intelligent” and can monitor real-time traffic situations, includingdirection, volume, and density, as wellas prioritize public transportationsystems, according to Welz.For example, Welz said, Siemens is working on aproject in Tampa, Florida, toimplement Connected Vehicle Technology.
This system allows the traffic light system to communicate directly with thecar and will improve safety and efficiency. Communications are sent from over40 traffic lights to cars equipped with the technology to receive the basicsafety messages either in the rearviewmirror or in-dash computer screen. Simple messages are sent to the cars using both pre-existingand newly installed technologies that allow a driver to receive informationsuch as the state of the upcoming traffic lights and recommendations on speedto get through both a particular intersection as well as the next handful oftraffic lights. This project has shown great increases in efficiency in howtraffic moves through intersections.2.5 Effects Of TrafficCongestionCongestion is a situation in which demand for road spaceexceeds supply. Congestion is the impedance vehicles impose on each other, dueto the speed-flow relationship, in conditions where the use of a transportsystem approaches capacity. 5 2.
6 Causes Of TrafficCongestionPoor road traffic management is the primary reason forextended periods of traffic congestion throughout the world. The worst trafficin the world occurs in Brazil, where people are stuck in traffic for up toabout 3 three hours per day. The issue of road congestion has affected bothdeveloping economies developed to varying degrees measures taken to contain theproblem.
Most urban areas have a critical congestion area where a large networkof roads converge and large traffic needs to traverse, for example, the toll gate that connects OzumbaMbadiwe and Lekki Epe expressway. Also, rapid burst in traffic over shortperiods of time can cause a catastrophic spiraling effect which will lead to acongestion collapse. In developing countries such as Nigeria, the issue ofmassive traffic explosion has worsened due to the following reasons: · Unplannedcities: cities and urban areas grow in an ad-hoc manner. With the growth, adequateprovision towards scaling the capacity in which roads can take is just notmade.
The lack of provision with respect to the growth leads to bottleneckroads.· Poordiscipline: often we see drivers jump red lights, have poor lane discipline oreven aren’t fully educated about traffic rules and regulations and block the intersection. This leads to traffic congestion.
Furthermore, poor traffic law enforcementsometimes gives no incentive for driversto obey the traffic rules.· Out-of-datemanagement: traffic centers are often uninhabited, allowing drivers to drive ina chaotic manner. Even if a union is controlled by a policeman or a trafficlight, the traffic junctions are largely independent of any traffic managementstrategy, optimizing only the respective trunk traffic flow, in the sense ofmaximum traffic accumulation. Inaddition, these approaches reinforce mismanagement of traffic on alreadycongested roads, accelerating the congestion collapse· Tighterbudgets: A significant amount of investment is required to set up a trafficmanagement infrastructure which can scale with the increasing traffic.
Such aninfrastructure not only involves measuring and analyzing real-time traffic databut also focuses towards enhancing congestion detection, solving real-time congestion and forecasting congestionscenarios. In developing countries, ravaged by corruption and bureaucracy,there are multiple hurdles before the money actually progresses towards suchlarge initiatives. 2Also, the causes of traffic congestion can be subdividedinto 2 categories, which are the recurrent and non-recurrent categories. The recurrentcongestion category covers congestion that occursdue to events that happen on a regular. They include physical capacity limitation,poor road network etc.
while the nonrecurrent congestion refers to congestioncaused by events which occur in a manner that isn’t regular. They include accidents,police checks, road closures due to construction and some others. 4Causes of congestion in NigeriaBashiru and Waziri (2008) highlighted the main causes oftraffic congestion in Lagos to be attributed to the following: illicit parking onthe street, high volume of vehicles on the road, narrow road, inadequatetraffic light at certain intersections, flooding and poor drainage, loading anddischarging of passengers. Even though the items listed above are notexhaustive of the causes of traffic congestion, Aworemi et al (2009) alsoagreed to the findings of Bashiru and Waziri after conducting a study with acase study on Lagos. To buttress the findings a survey was conducted at the AnnualGeneral Meeting (AGM) of the Nigerian Society of Engineers (NSE) wherequestionnaires were distributed among participants. The results from therespondents are shown in table 1. 5Table 1 Causes of Congestion in Nigeria Rank Causes of congestion No Percentage 1 Poor driving habits 161 82.
1 2 Poor parking habits 155 79.1 3 Poor road network 151 77.0 4 Inadequate road capacity 147 75.
0 5 Lack of parking facilities 139 70.9 6 Poor traffic control management 128 65.3 7 Poor drainage 124 63.
3 8 Presence of heavy vehicles 112 57.1 9 Poorly designed junction/roundabout 102 52.0 10 Lack of efficient mass transit 98 50.0 11 Lack of pedestrian facility 79 40.3 12 Malfunctioning vehicles 74 37.
8 13 Poor road pavement 68 34.7 14 Presence of construction activities 68 34.7 15 Lack of road furniture 59 30.1 16 Too many taxis 46 23.5 17 Excessive speeding 42 21.4 18 Frequent use of sirens 33 16.8 19 Poor weather 10 5.1 20 Others 0 0.
0 Causes of traffic congestion gotten from the InternationalJournal of Engineering and Technology Volume 2 No. 8, August 2012 2.7 Advantages2.8 Use of Sensors and TechnologyIn Traffic Managementaccording to theAdvanced English dictionary, a sensor isdefined as any device that receives a signal or stimulus (as heat or pressureor light or motion etc.) and responds to it in a distinctive manner.
With the ever-growingrise and rapid increase in population which in turnsgives rise to an increase in the number of commuters and vehicles on roadnetworks, it is no news that urban areas need to adopt an intelligent traffic system (ITS) to tackle this challenge.The use of sensors and technology has not only aided this development, but ithas also helped in forecasting through studying the patterns and behaviorsduring hours of days in certain road networks. 3 existing trafficsystem 1 Edward A. Mueller. Aspects of theHistory of Traffic Signals.
IEEETransactions Of Vehicular Technology, Vol. Vt-19, No. 12 Jain, V., Sharma, A., & Subramanian, L. (2012, March).
Road traffic congestion in the developing world. In Proceedings of the2nd ACM Symposium on Computing for Development (p. 11). ACM3 Chong, C. Y.
, & Kumar, S. P. (2003). Sensor networks:evolution, opportunities, and challenges.
Proceedings of the IEEE, 91(8),1247-1256.4 Chow, A. H., Santacreu, A., Tsapakis, I., Tanasaranond, G.,& Cheng, T.
(2014). Empirical assessment of urban traffic congestion. Journal of advancedtransportation, 48(8), 1000-1016.5 Ukpata, J. O., & Etika, A.
A. (2012). Traffic congestionin major cities of Nigeria. International Journal of Engineering andTechnology, 2(8), 1433-1438.