WO2010058413A1 - Non-merging non-intersecting traffic stream flyovers - Google Patents

Abstract

Flyovers are used to enhance the traffic handling capacity of any junction when the time domain control of vehicles at single level becomes inadequate due to increase of traffic and people becoming more aware about the value of their time. Conventional flyovers still need the traffic light control if they have to handle all the twelve streams at a four road junction. The state of art flyover, known as Clover Leaf Arrangement, dispenses with the traffic lights but has many shortcomings and limitations. New types of flyovers explained in this invention appropriately transpose various streams either at one end or at both ends of the flyover in such a manner that they allow each stream to go to its destination, without any interference from other streams. Hence, if appropriate lane has been taken while entering these flyovers, one reaches the desired destination road without any need of any deceleration anywhere.

Description

Non - Merging Non - Intersecting Traffic Stream Flyovers

This invention relates to new types of flyovers which, when used on a multiple road junction, shall permit all vehicles on each of these roads to go to the remaining roads simultaneously without any merging or intersecting interaction with other traffic streams, thereby obviating the need of traffic signals. In the end a method has been given for taking care of the vehicles wanting to return to the same road from which they have come. The system provides a limited unutilized space below the flyover for appropriate utilization by the authorities. Background art as well as novel features of proposed flyovers shall be explained with the help of following accompanying drawings.

(Figure- 1) - Twelve streams of Right Side Driving System.

(Figure-2) - Twelve streams of Left Side Driving System.

(Figure-3) - Twelve streams of Clover Leaf Arrangement.

(Figure-4) - Embodiment- 1/ (Figure-5) - Embodiment-2.

(Figure-6) - Embodiment-3.

(Figure-7) - Embodiment-4.

(Figure-8) - Attachment for handling U turn traffic.

In the course of explanations and comparisons with state of art systems, a short name shall be required for these new types of flyovers. For brevity, we shall refer them as Kumar's flyover(s).

To explain the background art, let us consider a four road junction having roads going to North, South, East and West directions. (These directions are only for explanations / drawings. In actual practice each direction will be completely independent). Complete transfer traffic at this junction can be divided into twelve streams. (Figure- 1) shows these twelve streams for Right Side Driving System being followed by countries like Germany and U.S.A. (Figure-2) shows the same twelve streams for Left Side Driving System being followed by countries like India and England. It may be observed that methods of conversion from one system to another are quite simple. One method is by changing the direction of arrows and interchanging two alphabets in the names of the roads. Another method is by taking the mirror image of the scheme and exchanging two alphabets corresponding to mirror image direction. AH subsequent discussions are, therefore, being worded for Right Side Driving System. Left Side Driving System shall be a natural derivative of the same by analogy.

As some lines in (Figure-1) are crossing each other, it is quite obvious that some form of traffic control shall be required to avoid the collision of vehicles. In the existing state of art, one of the methods of control is by time domain multiplexing of various streams. It is achieved either through traffic police or by traffic lights. They permit a set of nόn-intersecting streams to move at a time and hold the rest. Quite apparently, this is not a very desirable state of affairs, especially when the roads get more and more crowded and people start valuing their time. In such cases the Z-domain multiplexing is resorted to. This means that intersecting streams cross each others path at different heights instead of at different times. Transportation consultants design these flyovers by observing the strength of each stream and thereby deciding which streams should be taken to high level and which ones should be kept at low level. In most cases, all twelve streams can still not move simultaneously and time multiplexing remains inevitable along with Z-domain multiplexing. In the existing state of art, there is only one design of flyover which does not call for time domain traffic control and permits all the twelve streams simultaneously. This is known as Clover Leaf Arrangement. However, before discussing Clover Leaf Arrangement, we would like to introduce our special technique of representing flyovers.

In this representation, which we call as "3D Plan View", twelve streams of traffic are shown partly by dashed lines ( ) partly by continuous lines ( ) and partly by dash double dot lines ( - ^{• ■} - ^{■ •} - ^{• •} -) to represent the vehicles at Level-1, at Level-2 and during the transition stages respectively. Level-1 and Level-2 may be any permutation of ground level, underground level or high level; however, for explanations, we shall consider Level-1 as ground level and Level-2 as high level. "3D Plan View" of Clover Leaf Arrangement can now be represented as given in (Figure-3). Since the scheme is very well known to the people in this field, it is not being described here in detail. However, we shall discuss some of its shortcomings and limitations. During the explanations, we shall use the terms high level traffic and low level traffic. These terms denote the vehicles which shall go above the flyover and those which shall not go above the flyover, respectively.

In Clover Leaf Arrangement, first difficulty arises while we approach the junction. In all other existing systems, three streams which are reaching the junction, viz. right turning stream, straight going stream and left turning stream, approach the junction in same order from right to left. This appears to be logical sequence and also befits the psychology of the driver. However, Clover Leaf Arrangement does not permit such an approach. In Clover Leaf Arrangement, sequence of streams (from right to left) should be right turning stream, left turning stream and then straight going stream. To tackle the psychology of driver, we call left turning tracks as entry / exit lanes. Very elaborate and exhaustive ENTRY / EXIT sign-board systems are essential to supplement this scheme.

Second difficulty is faced only by the four streams wanting to turn left at the junction. Each of these streams has to exchange lanes with two other streams, one before the "Leaf, and another after the

"Leaf as is clear from (Figure-3). These lane exchanges require deceleration, mixing with vehicles, changing sides and again accelerating. These two lane exchanges and relatively longer path of "Leaf cause some petrol wastage for left turning vehicles. It can also be associated with some wear / tear and fatigue of roads / vehicles / passengers as well as some delays. An indirect disadvantage due to extra petrol consumption is extra pollution.

An auxiliary problem, which is not visible in today's scenario, may emerge after a decade or so. At that time, with heavy bumper to bumper traffic in each stream, exchanging lanes may become difficult. In that situation, Clover Leaf Arrangement will not be very effective for left turning streams.

Third disadvantage of Clover Leaf Arrangement is its large space consumption at a premium location of the city. Each "Leaf of this arrangement requires large radius for vehicles to change direction by 270° at a reasonably high speed. In most cases the location, where Clover Leaf Arrangement is planned, is heavily crowded area, probably in the heart of a big city and therefore cost of land at that place is quite high.

Another difficulty, which is a practical difficulty, arises from the fact that initially when cities are not very crowded, one does not plan for such elaborate traffic arrangements. Slowly as the population of the city goes up, more and more vehicles come on the road. At the same time, more and more buildings get constructed near the roads and the junctions. By the time one feels the need of regulating the traffic with elaborate arrangements, there are many buildings near the roads and junctions. At this point of time it is very difficult to implement the Clover Leaf Arrangement due to presence of these high priced buildings.

The invention explained herein involves a new concept of system designing. Flyovers made with this new concept, hereinafter called Kumar's flyover(s), not only permit all twelve streams of vehicles at a four road junction to go to their destinations simultaneously, but are also free from the shortcomings / limitations of Clover Leaf Arrangement explained earlier. In Kumar's flyovers, various streams are appropriately transposed either at one end of the flyover or at both ends of the flyover, so as to form compatible combinations at each level. Two embodiments each, for both these types of transpositions shall be presented during forthcoming description. Technical comparison of Kumar's flyovers with the known state of art viz. traffic lights and Clover Leaf Arrangement is given in (Table-1). Relative advantages of Kumar's flyovers over otlier methods are quite apparent.

Embodiments based on appropriate transposition of streams after the flyover will now be explained. (Figure-4) and (Figure-5) give "3D Plan View" of Kumar's flyovers for these embodiments. In these embodiments, all vehicles wanting to take a left turn have to cross the junction along with the straight going stream and thereafter take a semi-U turn by suitable extension of flyover to reach their destinations. For high level traffic, these extensions remain a part of the flyover while for the low level traffic these extensions may or may not be part of the main structure. (Figure-4) shows these extensions not being a part of the main structure while (Figured) is suitable for single structure construction.

Before describing the other embodiments involving appropriate transposition of vehicles at both ends of flyover, some theory will be briefly explained. From (Figure- 1) & (Figure-2) it can be seen that in either system, when all vehicles are at same level, a maximum of only six streams can move freely at a time,. The combination of such six streams is, however, not unique. Many sets of such six streams are possible. For example, in case of (Figure-!), some such sets are (NW, WS, NS, SE, EN, SN), (NW, WN, WE, WS, SE, EN) and (NE, NW, WE, WS, SE, EN). In case of flyovers, where two levels are available for movement of vehicles, it is ppssible to have free flow of six streams at ground level and free flow of remaining six streams at high level. It is, however, not possible to find two mutually exclusive sets of six free flow streams each, in either of the driving systems. Kumar's flyovers, therefore, transpose the remaining six streams appropriately, after negotiating the ramps, so that they form a free flow combination at high level. While bringing them back to the ground level, the flyover must inverse transpose these vehicles, so that they again form a part of the normal traffic.

Third embodiment, which is one of the examples of appropriate transposition of vehicles at both ends of flyover, will now be explained with the help of "3D Plan View" shown in (Figure-6). In this embodiment, six streams which remain at ground level throughout are NW, WS, NS, SE, EN and SN. Remaining six streams have been taken to high level. In order to get their free flow combination at high level, all vehicles climbing the flyover are made to cross some traffic coming from opposite direction after reaching top level. When the desired roads have been reached, these vehicles get the inverse transpose transformation automatically, so as to form the part of normal traffic at the ground level. (Figure-7) gives an alternative embodiment for similar requirement. Design assumes heavy long distance traffic in N-S direction and therefore this traffic is kept at ground level all the time. Design will vary depending upon actual requirement.

It should be noted that in (Figure-4) (Figure-5) (Figure-6) as well as (Figure-7), when any vehicle is during the transition stage, there is no vehicle either vertically above it or vertically below it. This ensures that maximum height of the vehicle is limited only by the height of the flyover and not by the clearances in the flyover design. For ease of understanding of concept, all these embodiments are in simplified form and kept free from technical details. During actual design, many alignments and adjustments will be carried out to optimize the cost and the space. In final design, some ground level space may remain unutilized below the flyover ramps. This can be utilized for some useful purpose such as making of cabins for the traffic police or VIP parking. Two aspects of traffic, which have not been touched upon so far, are a) Pedestrian movement b) Vehicles wanting to take U turn i.e. wanting to go back to the road from which they have come.

These can be taken care of in the following manner. For pedestrians, an underground subway can be made, so that they do not disturb or get disturbed by the free flow of vehicles. One of the alternatives to take care of U turn traffic is given in (Figure-8), where a four-stream traffic is converted into a three-stream traffic before it reaches the flyover.

In the beginning, design of these flyovers may not be very clear to the drivers. They should, therefore, be told to select their destination road before entering the flyover and thereafter remain in the lane marked on the road. They will automatically reach their destination because Kumar's flyovers do not call for any lane changing or lane crossing.

It may be stated here that Kumar's flyovers can also be designed for systems requiring either less or more than twelve streams. Schemes for them will have to be worked out on case to case basis with similar methodology.

( Table - 1 ) COMPARISION BETWEEN VARIOUS ALTERNATIVES AT FOUR ROAD JUNCTION

(EXPLANATION WORDED FOR RIGHT SIDE DRIVING-SYSTEM)

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Claims

CLAIMS; I claim,

(1) Flyovers, comprising of independent non-merging and non-intersecting lanes for each stream of traffic at any junction, such that they form non-interacting combinations of streams at all levels, by using the technique of appropriate transposition either at one end or at both ends of the flyover, with the help of suitable extensions or modifications, in such a way that entire movement of every vehicle at that junction is without any need of deceleration or stoppage of vehicles while the streams remain compatible with prevalent traffic system before and after the flyover.

(2) Flyovers, characterized by their use at any junction in Right Side Driving System or Left Side Driving System in such a manner that the transposition of streams at any or both ends of the flyover enables all the streams of vehicles in every lane to go to their destination roads without any need to move into adjoining lanes, thereby, permitting even a bumper to bumper traffic in each stream to go to its destination, without decelerating or stopping and without any interference from other streams.

(3) Flyovers, substantially as described herein and illustrated in the figures given in accompanying drawings.