US3238854A

US3238854A - Continuous-flow traffic interchange

Info

Publication number: US3238854A
Application number: US245778A
Authority: US
Inventors: Okubo Kentaro
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-12-22
Filing date: 1962-12-19
Publication date: 1966-03-08
Anticipated expiration: 1983-03-08

Description

KENTARO OKUBO CONTINUOUS-FLOW TRAFFIC INTERCHANGE March 8, 1966 2 Sheets-Sheet 1 Filed Dec.

March 8, 1966 KENTARO OKUBO CONTINUOUS-FLOW TRAFFIC INTERCHANGE 2 Sheets-Sheet 2 Filed Dec. 19 1962 United States Patent 3,23%,854 CDNTlNlUQUS-FLGW TRAFFEC HNTERCHANGE Kentaro (limbo, 1-437 Saginorniya, Nakano-ku, Tokyo-to, .lapan Filed Dec. 19, 1962, Ser. No. 245,778 Claims priority, application Japan, Dec. 22, 1961, 36/ 46,320 1 Claim. (Cl. 94-11) This invention relates to traffic intersections, and more particularly it relates to intersections or interchanges which are so designed as to permit continuous flow of trafiic on intersecting streets.

The term street is herein used in the sense of its including roads, highways, avenues, boulevards, and the like, each of which carries traffic in at least one direction and, in most cases, in two mutually opposite directions. It will be obvious that the invention is applicable also to intersection of streets with other right of way such as railway lines.

With the ever-increasing number of vehicles, trafiic congestion is a major problem in numerous places throughout the world, and the prime problem in alleviating this congestion inevitably converges to that of efiicient handling of traific at intersections.

The present invention in its broader aspects contemplates providing a new street intersection means of relatively simple construction disposed within the confines of the thoroughfare or the so-called right of way, wherein, by utilizing multi-level crossing and avoiding grade crossing, continuous and smooth traflic flow and increase in traific handling capacity are realized, and trafiic interruptions, delays, interference, and accidents are preented.

Fundamentally considered, a grade crossing is created by the imposition at an intersection center of one street on another street directed in a different direction. In endeavoring to avoid grade crossing, the mere separation of traffic flows by resorting to diiierent levels is unsatisfactory since this leads to multiple overlapping or stacking of different levels at the intersection center, this stacking increasing excessively with the increase of interchange requirements. The present invention, briefly described, contemplates preventing this excessive stacking by directing the route of each inbound vehicle intending to make a left turn (in the case of right-hand trafiic) to pass always over a U-shaped, elevated bridge up to the cross street so as to cause the said vehicle to make a remote detour before it passes beyond the intersection center, the said elevate-d bridge being built over the other lanes and having one end communicating with the intersection center part and the end communicating with a grade passage; and directing the lanes of the street forming the intersection to communicate with the intersection center part, the through lanes being directed in straight lines and crossing at two levels, whereby grade crossing is avoided.

The nature and details of the invention will be more clearly apparent by reference to the following description taken in conjunction with the accompanying drawings in which like parts are designated by like reference numerals and letters, and in which:

FIG. 1 presents views showing one embodiment of the invention as applied to an intersection of two streets, FIG. 1(A) being a plan view, FIG. 1(B) being an elevational view, as viewed toward x of FIG. 1(A), and FIG. 1(C) being an elevational view, as viewed toward y of FIG.

FIG. 2 presents views showing the basic configuration of the interchange according to the invention, FIG. 2(A) being a plan view, FIG. 2(B) being an elevational view toward y in FIG. 2(A) (the part G being an elevated overpass), and FIG. 2(C) being an elevational view toward y in FIG. 2(A) (the part G being a depressed underpass).

Referring to FIG. 1, the axes of the intersecting streets will be denoted respectively by xx' and yy. A crossing throughway A (an overpass in this case) crossing three-dimensionally over the street x-x' in the direction y-y' is provided, and the two ends of the crossing through- Way A are connected to the leg y and leg y of the street y-y by ramps. Reference letters B, C, D, and E designate U-shaped elevated roadways, each bridging over, respectively, one of the four legs x, y, x, and y of the two streets in the vicinity of the intersection center, the concave sides of the U-shaped roadways B and D mutually facing each other, and those of roadways C and E mutually facing each other. The elevated roadways B and D are connected, respectively, to the grade-level street x-x' by ascending ramps a and from the direction of the intersection center part and by descending ramps b and [2 toward the intersection center part. The elevated roadways C and E are connected, respectively, to the street yy' by ascending ramps a and a, from the intersection center part and are connected to center crossing throughway A by converging lanes b and b.,. Accordingly, the elevated roadways A, B, C, D, and E and the lanes [1 and b, are disposed in substantially the same horizontal plane.

The traffic flows of the interchange of the abovedescribed constructional arrangement will now be described in detail. The flow of through traffic in the y y direction passes under (crosses three-dimensionally) the elevated roadway E as indicated by arrow 1, enters the throughway A at arrow 2, passes under (crosses threedimensionally) the elevated roadway C at arrow 3, and proceeds through toward y. The flow of traffic in the y x direction flows as indicated by arrows 4, 5, and 6, passing under the lane [1 separates from path 6, enters the ascending ramp a flows as indicated by

arrows

8 and 9 along the roadway D, converges at portion 10 with the trafiic in the x'- x direction, passes under (crosses three-dimensionally) the throughway A at arrow 11 and under the roadway B at arrow 12, and proceeds toward x. The flow of traffic in the y x' direction flows along the path indicated by arrows 4, 5, 6, and 7, converging with the traffic in the xe x direction, passes under (crosses three-dimensionally) the roadway D, and proceeds toward x.

Similarly, the traflic in the x' x direction flows as indicated by

arrows

13, 14, and 15 in sequence; the traffic in the x y direction flows as indicated by

arrows

16, 17, 18, 19, and 20 in sequence; the traffic in the x+y direction flows as indicated by

arrows

16, 17, and 18, then, separating from path 18, flows as indicated by

arrows

21, 22, 23, 24, 25, 26, and 27 in sequence; the traffic in the y y direction flows as indicated by arrows 2 8, 29, 30, and 31 in sequence; the traffic in the y' x direction flows as indicated by

arrows

32, 33, and 12 in sequence; the trafiic in the yex' direction flows as indicated by

arrows

32, 33, 34, 35, 36, 37, and 38 in sequence; the traffic flow in the xx' direction flows as indicated by

arrows

39, 40, and 38 in sequence; the traffic flow in the x y direction flows as indicated by arrows 41, 42, 43, and 44 in sequence; and the traffic in the x+y' direction flows as indicated by arrows 41, 42, 43, 45, 46, 4-7, 48, 49, and 50 in sequence.

Since, as described above, the division of traffic flows is thorough, the most important conditions relating to interchanges are fulfilled, that is, (1) weaving is prevented, (2) decision on three driving conditions at one point is not required, and (3) there is no merging with or exit from the right lane. Furthermore, the interchange as described above affords economy of land area and simplicity of traffic flow and of construction, wherefore the interchange facilitates designing to suit any intercharge requirement and, moreover, affords lowering of costs. That is, this interchange is highly suitable for increasing trafiic handling capacity as a total result although the speed of the left-turning trafiic is sacrificed somewhat.

The fundamental form of the concept of the present invention is diagrammatically indicated in FIG. 2, in which the center roadway is designated by reference letter G. in FIG. 2, reference letters B and C designate U-shaped crossing roadways crossing three-dimensionally over extensions of street legs of the center roadway G. The roadways B and C are respectively connected, at one end of each, to the center roadway G by connecting roadways b and provided on both sides of the center roadway G. The roadways B and C are further connected, at the other end of each, to the grade level street by ramps a and a respectively, the said ramps being open at their ends communicating with the grade level street. The level of the center roadway G is above or below depending on the place of use as indicated in FIG. 2(8) and FIG. 2(C).

The above-described constructional arrangement is based on the following conditions. Elevated U-shaped bridges adapted to fit within the width of the streets at the site where the interchange is to be constructed are disposed on the two ends of the intersection center part A with their respective exits and entrances always facing the center part A, either of the exit and entrance of each elevated U-shaped bridge being made to communicate with the grade level street, and the other being made to communicate with a path which detours remotely from the center part G and is directed, by way of the center part G as an intermediary medium, toward the intended destination route; and a vehicle intending to travel on an elevated U-shaped bridge is caused to enter the route leading to the said bridge before the vehicle arrives at the center part A and to complete a U-turn prior to its arrival at the center part A. In actual application, the above-described structural arrangement is taken as a single unit, and, in accordance with the requirements of interchange, a single unit is used, or a plurality of units are used at varied angles and in three-dimensional superposition. Accordingly, the interchange according to the present invention can be applied in a planar manner to intersections of any number of ways or street legs such as, for example, three-way and four-way intersections, and can be used in a three-dimensional manner for intersections of any number of ways with any number of levels.

Thus, the interchange of this invention does not occupy a large space as in the case of many conventional interchanges for the same purpose. Consequently, it can be built freely above and below ground level. Furthermore, this interchange does not cause confusion for drivers using it, and since the selection of and decision on the 4. intended destination route can. be made freely and easily at the place of intersection, there is no necessity of excessive travel in order to change travel direction as in the case of some conventional systems comprising a network of streets with combinations of intersections at several places, and there is no possibility of confusion and congestion within an urban area. Therefore, the interchange according to the present invention is highly suitable, convenient, and advantageous particularly for intersections of urban streets.

Although this invention has been described with respect to specific embodiment thereof, it is not to be so limited since changes and modifications can be made therein, as will be obvious to those skilled in the art, which are within the full intended scope of the invention, as defined by the appended claim.

What is claimed is:

A continuous trafiic flow interchange for two intersecting streets, the first street passing under the second street at the point of intersection, a U-shaped cross bridge spanning each of said streets and transverse thereto on each side of and spaced outwardly of said point of intersection, the concave portions ot the bridges facing said point of intersection, each cross bridge having an inlet side leg and an outlet side leg, a central longitudinal portion of each street defining a throughway, the inlet side legs of said cross bridges being positioned outside of said throughways and inclined from street level, the outlet side legs of each cross bridge communicating with the throughway adjacent thereto communication with said first street being at street level and communication with said second street being at the overpassing portion of the second street, the first street communicating with the inlet side legs of the cross bridges on the second street and the second street communicating with the inlet side legs of the cross bridges on the first street.

References Cited by the Examiner FOREIGN PATENTS 12/1928 Great Britain.

OTHER REFERENCES CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, Examiner.

N. C. BYERS, Assistant Examiner.