İstanbul Harp Akademileri katlı kavşağının düzenlenmesinde yeni bir öneri ve ekonomik kıyaslama

Abstract

Günümüzde, İstanbul gibi hızlı nüfus artışı ve çarpık kentleşmenin yoğun olarak görüldüğü büyük kentlerde, kamuoyunun en büyük problemlerinden birinin ulaşım olduğu bir gerçektir. Özellikle düzensiz büyüyen kentlerde, bu sorun hayatı büyük ölçüde aksatmaktadır. Belki de ulaştırma problemlerinin tek sebebi her kesimde olduğu gibi talebi karşılayacak bir arzın bulunmayışıdır. İstanbul'da ulaşım probleminin giderek büyüdüğü bölgelerden biri de Zincirlikuyu, Levent, Maslak, Sarıyer hattının trafiğini taşıyan Büyükdere Caddesidir. Bu çalışmada, pik saatlerde çok yoğun bir trafiğe sahip olan Büyükdere Caddesi'nin ana kavşaklarından biri olan Harp Akademileri ve Sanayi Mahallesi arasındaki üç katlı kavşağın, ulaşım planı üzerinde yapılacak birtakım düzenlemeler öneri olarak incelenecek ve bunların doğuracağı sonuçlar ele alınacaktır. Tez çalışması dört bölümden ibaret olup ilk bölümü, kavşak planlama elemanları ve genel kavşak planlama esaslarına ayrılmıştır. İkinci bölüm sözü edilen kavşağın mevcut kullanım planı ve beraberinde getirdiği trafik sorunlarına ayrılmıştır. Üçüncü bölümde sözkonusu kavşakta yapılması önerilen düzenlemeler, karşılaşılan engeller ve bu engellerin aşılması için yapılan çalışmalar belirtilmiştir. Dördüncü bölümde ise önerilen düzenleme çalışmasının meydana getirebileceği fayda ve maliyetlerin değerlendirmeleri yapılmıştır. Tezin sonunda ise; yapılan çalışmanın sonuçları hakkında genel bilgiler verilmiştir.

After the 0-2 motorway that is directly connected to Second Bosphorus Bridge (FSM Bridge) is opened to traffic, it availed an obvious relief in the Istanbul traffic. This relief manifested itself more by routing a certain amount of the traffic burden sustained by the 0-1 ring road that is served both the inner-city traffic and the transit traffic, to 0-2 motorway. In fact, greater amount of current traffic burden of 0-1 ring road having direct access to the First Bosphorus Bridge is originating from the metropolis of Istanbul itself in which population snowballed and urban settlement areas expanded out of the original city periphery. Meanwhile adding the uncalled for burden of the transit passage traffic onto the existing congested inner-city traffic caused overburdening of the 0-1 ring road bringing the vital necessity of constructing a new ring road into the national agenda. In this regard the 0-2 ring road attracted first the transit traffic than the inner-city traffic. One of the regions that the traffic problem increases is the Büyükdere Caddesi that carries the traffic of Zincirlikuyu, Maslak and Sarıyer line. In this study, which consists of four sections, the arrangements in the transportation plan on the one of the most important intersection in this line, the three levelled intersection of War Academies and Industry District is examined and the probable results is studied. After crossing FSM Bridge from Asia Minor to European Side of the straits, a right turn routes to Sanyer-Maslak direction, then makes a gentle left turn and passes under the motorway and after making a right turn and gains access to Büykdere Caddesi in vicinity of 4th Levent. Despite when this access road is opened to traffic, there was no dilemmas either at the motorway, this access road or at that section of Büyükdere Caddesi, after a while urban developments lived up to in the vicinity leading to mushrooming of industrial neighborhoods, large hotels, shopping-malls, universities and other educational facilities, residental housing, the stock exchange gave birth to extremely compact traffic in between Zincirlikuyu-Maslak section of the Büyükdere Caddesi, adding the traffic coming from ring V1U road to this main artery, especially the 4th Levent section of the Boulevard and other sections were almost paralyzed representing a nightmare to motorists and the environment alike. In the first section of this study, theorical rules of the planning of an interchange is considered. The planning of an interchange is the most important part of the planning in project making. Because the interchange capacity and interchange security is the most important factor that determines the whole security and capacity of the whole road. It is a wide known knowledge that the percentage of the accidents in the interchanges is much more compared to the other parts of the motorways. Besides the seriousness of the accidents in the interchanges are much more heavier compared to the other parts of the motorways. Likewise the capacity of the traffic volume transparency of a road web is limited with the capacity of the interchanges. One of the reasons of this limitation is that the drivers get more timid and suspicious in the interchanges and another reason is that the present space assigned to the traffic in the interchange should be assigned seperately to the traffic in terms of time and space. In the second section, the interchange's current state is explained. War Academies Interchange is a three-level interchange that is located in Istanbul's Şişli province. In the north east direction of the interchange the War Academies that gives its name to the interchange is located and in the north west direction is 3. Division Military Zone is located. The War Academies Interchange was built under the control of TCK General Directory by Freeman Fox - Botek companies and although it has provided many benefits to Istanbul's traffic it also brings some deficits. When the interchange was built there was no intense traffic in Büyükdere line, but in the recent years as a result of the city growth in Sarıyer district the traffic density has intensified more than expected. Therefore there are traffic jams in the line especially in the hours of dense traffic. The main reason for the traffic jams is that the supply is not enough for the demand especially in morning and night hours when the traffic density is in maximum. In the morning hours the traffic is intensified by the vehicles coming to the line in Levent, Zincirlikuyu and Beşiktaş districts and in later hours by the vehicles that join the line in farther districts to Maslak-Sanyer region, plus the vehicles that come from the Anatolian side by Fatih Sultan Mehmet Bridge and join the same traffic, causes waste of times and accidents, losses in the country's economy and environment and causes unrepairable IX destruction on human physchology. The same traffic jams happens in the revers direction at night hours, and therefore the deficiencies on Büyükdere Road should be removed and new arrangements should be made without any delay. It is obvious that if the negative effects of the traffic that joins the line from the Anatolian side or leaves the line to the Anatolian side in morning and night hours towards Sarıyer direction of Büyükdere Caddesi is minimised, will add great benefits to the transportation of this line. In the existing transportation plan a vehicle that comes from Anatolian side and goes through Sarıyer distrct after passing Fatih Sultan Mehmet Bridge will enter the interchange at the back of Sabancı Business Center in 4th Levent and join Büyükdere road. Likewise any vehicle that comes from Sarıyer district and wants to do to Anatolian side in the shortest way will have to go to the interchange that is in 4th Levent that joins to TEM motorway. On the other hand The War Academies Interchange, as placed where it is, is in a good position, to solve this problem after a few arrangements. In the third section, arrangement studies of the interchange is considered. When the projects of War Academies Interchange was made in September 1987, various traffic problems of the future was beard in mind. But since this district was one of the strategic regions of Turkish Armed Forces, that is in the east part of Büyükdere Caddesi, in the presence of War Academies in the east and 3. Division Military zone in the west of the interchange has caused special planning in projection phase. Because of sensitivity of military in usage of land, in the projection phase the standarts could not be applied in this interchange. On the other hand in the projection phase the present and future traffic demand was planned to be solved by a sub-tunnel under the interchange but again by military security measures this thought was not applied as well. In the years when this interchange was built, there were no traffic jams because the traffic was not intense. But if we take the conditions of the present traffic conditions at hand, by arranging a few measures the traffic jams can be solved completely. The traffic jams in the War Academies Interchange especially in the peak hours, and the cost-benefit analysis for the interchange is made in especially in terms of economical angle, in time waste and environmental effects a few arrangements that will solve the problem that will not cause a great amount is aimed by this study. Because of the specific condition of the War Academies Interchange, for the new intersections extra roads the limited and sloppy land will be used. The new Ci road's portion to the walls of the military, and the new C2 road's portion that will take place in the green area towards Industry District is highly sloppy, the reglage studies in arranging these lands is intensified. To prevent land slide after making cuttings and horizantify the land the building of retraining walls is inevitable. Because of land limitations in planning extra interchange roads minimum curp radius' of interchange planning standarts is applied. Extra interchange roads is named with the directions of their service aims as follows: The extra interchange road that will serve to the vehicles that will pass FSM Bridge and go towards Sarıyer or Beşiktaş : Ei road (Ei road will also serve the vehicles that want to turn to the direction they came from by using clover joint) The extra interchange road that will serve vehicles that come from Sarıyer or Beşiktaş direction and want to use TEM motorway to go to Anatolian side : E2 road To provide the minimum standarts wanted in the tender documents Ci extra interchange road has been taken to 3. Division Military zone's direction (north direction) and enlarged. The C2 extra interchange road has been taken to Industry District's direction (south direction) for the same reasons. Ei and E2 extra interchange roads wideness has been made 7.00 metres in alignments, and in horizontal curbs widened to 8.75 metres in projects as the widening conditions demand. The extra interchange roads is planned in two lanes and has a continuous banquet 1 metre width. In Ei and E2 roads the minimum standarts are applied due to the topographic conditions of the land, and therefore due to speed limitations the application of traffic signs is extremely important. In the fourth section, a comparison of benefit-cost is considered for the interchange. The most important diffuculty in evaluating a project is calculating the benefit and cost of the project with the second best alternative, if this is not done and if the project is compared with the third or fourth alternative, the projects relative benefits or costs to the second best alternative will be exaggrated. To XI calculate of the alternatives will be highly costly and will take a lot of time, therefore to choose the alternatives worth to calculate in detail will take a lot of knowledge and experience. The calculation of a project is usually based on "with" or "without" evaluation : if the project is not realised what will be the future flow of cost and benefits, and what will they be if the project is realised ? The studies' aim was not to prepare feasibility study, but to find put the benefits or damages if the interchange was revised, to make a pre-study about this subject, and to find out economical comparing methods. The north of Büyükdere Caddesi - Maslak, Sarıyer line - was not one of the central places of İstanbul in 1990's. But in the following years due to extreme urbanisation is region became one of the central attraction places (universities, hotels, multi-storey business centers) of the city. The urbanisation of this region is still intensified at the and of 1996. Due to extreme urbanisation, traffic jams are seen especially from Sarıyer direction to Anatolian side and vica verca. After rearranging this interchange there will be great gains in countries economics in long term, by ending the traffic jams, the drivers will lose less time and have petrol economy, potential accidents and environmental defects will decrease in percentage, the negative effects of traffic jams in human psycology will be at minimum. By stopping traffic jams the travel conditions will be more secure, faster and more comfortable. In the last section, the general results of this study is considered in brief.