Sağa dönüş çarpanının doğru giden ve sağa dönen akımları içeren şeritler için araştırılması: İstanbul örneği
Investigation of right turning factor for the lanes which have through and right turning flows: Istanbul example
Yazar: GÜLÜZAR GÜR
Danışman: DOÇ. DR. KEMAL SELÇUK ÖĞÜT
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Ulaştırma Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2017
Konu: Trafik = Traffic ; Ulaşım = Transportation

Özet:
Ulaşım, geçmişten günümüze her zaman aynı önemi taşımıştır. Ulaşım sorunu ise teknoloji alanında yaşanan gelişmeler sayesinde gerek bireysel taşıtlar gerekse gelişen toplu taşıma araçları yardımıyla çözüme varmıştır. Ulaşım sorunu çözüme ulaştırılmaya çalışılırken; nüfus artışı, taşıt fazlalığı ve çeşitliliği, daha büyük bir sorunu, trafik sorununu ortaya çıkartmıştır. Şehir içi trafiklerinde çözümlenmesi gereken en önemli noktalar kavşak alanlarıdır. 
Trafik hacminin belirli bir değeri aştığı kavşakların işletilmesinde ülkemizde genellikle ışık denetiminden yararlanılmaktadır. Bu kavşaklarda ışık alanı düzenlerinin ya da ışık sürelerinin yanlış tasarlanması, kavşak kapasitesini düşürmekte ve önemli gecikmelere yol açmaktadır. 
Doygun akım değeri, trafik ışığı hesabının ve kavşak kapasite değerlendirmesinin temel büyüklüklerinden birisidir. Doygun akım değeri çeşitli trafik ışığı kapasitesi el kitaplarında, bu büyüklüğü etkileyen değişkenler yardımı ile hesaplandığı gibi doğrudan saha ölçümleri yardımı ile de bulunabilmektedir.
Yapılan bu yüksek lisans tez çalışmasında doygun akım değerini etkileyen bir etmen olan sağa dönüş çarpanının, aynı şeritte doğru giden akımların olması durumu için hesaplanması amaçlanmıştır.  Bu çalışmanın ana hedefi İstanbul için doğru giden ve sağa dönen akımların kullandığı aynı şeritte doygun akım değeri hesaplamak ve sağa dönen taşıtların doğru giden taşıtları nasıl etkilediğini araştırmaktır. 
Bu amaç doğrultusunda, saha gözlemlerinin yapılabilmesi için, İstanbul'da dört adet ışıklı kavşak seçilmiştir. Kavşaklarda eğim, ağır taşıt yüzdesi, otobüs durağı ve parklanma etmenlerinin olmamasına dikkat edilerek seçim yapılmıştır. Ölçümler yapılırken, taşıtlar arasındaki zaman cinsinden aralıklar ölçülmüş, ölçüm yapılan taşıtlardan sağa dönen ve doğru gidenler belirlenmiştir. Bu şekilde sağa giden taşıtların doğru gidenleri ne  kadar etkilediği de bulunmuştur. Her kavşakta yalnızca tek şeritte ölçüm yapılmıştır. 
Sağa dönen ve doğru giden akımların aynı şeritte yer alması durumunda zaman cinsinden doygun aralığı etkileyen çeşitli değişkenlerin olduğu ortaya koyulmuş ve  bu değişkenlerin belirlenip sağa dönüş çarpanının hesaplanabilmesi için bu değişkenler incelenmiştir. 
İncelenen değişkenler arasında sağa dönüş çarpanı ile ilişkili olan değişkenin dönüş iç yarıçapı olduğu belirlenmiştir. Bu doğrultuda bulunan denklem ile sağa dönüş oranı ve dönüş iç yarıçapı verileri ile sağa dönüş çarpanı elde edilmiştir. Buna göre dönüş yarıçapının azalması ve sağa dönüş oranının artmasının sağa dönüş çarpanının azalmasına neden olduğu sonucu ortaya koyulmuştur.

Abstract:
The development of mankind, cultural and technical interactions, is in parallel to the development of transportation. Population growth and the increasing number of vehicles with emerging technologies, brings problems such as traffic congestion. This problem must be solved to offer comfortable life to the citizens. In our country with population growth especially in big cities have been experiencing serious traffic problems as a result of the increase in transport demand. Congestions and delays have been inevitable at signalized intersections which have low speed because of heavy traffic conditions.
Transportation has the same importance of humanity life for every time. The cause of transportation has been solved by personal cars and mass transportation vehicles. Over population, increasing and variety of vehicles causes traffic problem as more important problem than transportation problem. The basic matter of the traffic in city is intersection area which crossing of different direction volume.
Saturation flow rate parameters in determination of intersection performance at signalized intersection system which is especially located in urban road network. In this study, these values were investigated using simple analytical and modeling method. Analysis was carried out considering geometric parameters, traffic parameters (turning rates) and control parameters (phase plans, signal duration).
In Turkey, usually signalization systems are being used to solve the intersection congestion problems. Incorrect design of the signal systems reduces intersection capacity, causes delays and accidents.
Saturated flow rate is one of the basic parameters of signaling calculation and intersection capacity assessment. The saturation flow rate can either be determined by the aid of adaptation factors described in the various signal capacity manuals or directly by field measurements.
In the first stage, vehicle tracking range methods, which are an important factor in the saturation current value, have been investigated. The most widely used method, time interval method, is used in this study. This is preferred because of the more convenient and accurate results obtained in measurements made on the field. Saturated current calculation methods are also investigated. Here too, the factors affecting the saturated flow are listed and all are explained one by one. From these, it has been examined in detail how the conditions of the right and left turns, which are important in the thesis study, affect the saturated current value.
In this study, it is aimed to calculate the right turn factor for traffic lanes that allow through and right turning movements. The main objective of this study is to calculate the saturation flow rate current value for such lanes in İstanbul. 
In order to realize the aim of this study, four signalized intersections were selected in Istanbul for data collection. The crossroads investigated are located in Kadıköy, Üsküdar, Maltepe and Pendik districts. Strip widths, number of lanes and radius of rotation for intersections were determined in the study. Right turn ratios along these lines are also listed on the intersection basis and are associated with these properties. These intersections are determined by the criteria that no gradient, heavy vehicle, bus stop and parking effects are present. The field study consist of the measurement of vehicle headways and determination of right turning and through going vehicles. By this way, the effect of right turning vehicles on through moving and following right turning vehicles was also found. At each intersection, only one lane was taken into account for the calculations. 
Saturation time intervals for intersections were determined in the measurements made. It has been determined from the vehicle that the saturation value has been reached in the junctions. ANOVA test was also used when this was determined. The ANOVA test is used to test the hypothesis as to whether the difference between the means of two or more groups is statistically significant.
The result is that the movements of the drivers in the intersection area greatly affect the interval values of the time at which the vehicle departs from the junctions of the other vehicles and thus leaves the junction at the tail.
After determining the interval zone in time at the junctions, it was attempted to determine how far back the effect of the vehicles turning to the right in this area was. Taking into consideration the number of vehicles on the tail (10 vehicles), two options were examined: vehicles turning to the right do not affect the vehicles behind and vehicles that turn to the right affect the vehicle behind.
These examinations were carried out in the form of three different situations in time domain intervals and their comparison. In these cases, all vehicles are listed as the case where the vehicles turning to the right are removed, and the case where the vehicle that turns to the right and the vehicle behind is removed.
At each crossroads, there were statistically insignificant differences in mean time intervals according to the order of the vehicles on the tail. In this case, the change was calculated according to the order of the vehicles on the tail at the crossroads.
In the case of the right and returning currents in the same lane, various variables affecting the saturation interval in time are shown and these variables are examined in order to determine the right and left turn factors. Interaction variables were formed by multiplying, dividing, or vice versa among the specific variables studied.
Graphs showing the relationship between the obtained 11 variables and D 's were obtained. Possible variables affecting the rate of change are listed and a correlation matrix is established between these variables.
According to the obtained correlation matrix, the most strongly correlated variable with D is Psag / DY, which is an interaction variable obtained by the turn radius ratio of turn radius. A regression model was calculated using this variable.
The equation is established based on the relation between saturated current value and time-saturated range, and how saturation current value is affected in case of right-going lane return.
It has been shown how the right turn multiplier is affected by the right turn ratio and turn radius.It was determined that the variable associated with the right turn multiplier is the return inner radius. With the equation found in this direction, right turn ratio and return inner radius data and left turn multiplier are obtained. Accordingly, the decrease in the turn radius and the increase in the right turn ratio result in a decrease in the right turn ratio.