CITY TRAFFIC JAM
(Compromise solution of a problem)

The problem of traffic blocks in streets of old cities interests not only automobilists all over the world, but pedestrians also almost in the same degree. Indeed in traffic jams not only personal transport, but also public transport stands. Of course, you may ask yourself, why this problem is solved by no means, and dig in it till the end of time. But also it is possible simply and unpretentiously to indicate the main stumbling-block, which for some reason remains invisible, and to receive quite reasonable, all-around decision of the problem, satisfying all or nearly all the desirable properties, namely, technical, economic, architectural, organizational, aesthetic, etc.

At that the presence of a problem itself looks rather strangely. The problem is on hand, and it is simple and clear. Scales of the problem are enormous, as it is a world problem. To decide this problem the authorities as customers will provide as much money as necessary, if not at their’s own will, than under pressure of the population. And as for the consumers, there is no need to search for them.. They are here, there and everywhere. There are more technical opportunities of manufacture than it is necessary. Man power is in large excess. It is possible to involve here as much investment, private financial assets for the organization of contract manufactures as it is required. What is needed is only to show the acceptable solution. And this is the thing that neither authorities, nor the market of private investments have at their disposal. A strange and ridiculous picture of causeless deadlock. Though from the physical and technical point of view there is no deadlock in this situation and never was.

I think, nobody or nearly nobody start to deny, that the problem of jams is of technical character and occurs at crossing of the transport streams on crossroads. Certainly, the question is in the system origin of the problem, that is any mass, almost suddenly arisen lacks of streets, highways, passes. As to the auto accidents, which cause the jams, they are of accidental, extreme nature and not of system one. Yet they often result from them. But at liquidation of a problem of crossroads, the problem of the auto accidents connected with them disappears accordingly.

At the same time, for some reason all the attempts to resolve the problem avoid a separate crossroads itself and bear global character, which expands even up to the loss of connection with the ground. That is the roads based on the roofs of houses, astonishing city trains, highways accompanied by demolition of hundreds and thousands of houses, trestles over streets… But nobody wants to descend up to such a trifle as a separate crossroads. As a result everything rests on the crossroads bottleneck. And all one need to do is to solve qualitatively and realistically the problem of the most usual crossroads and to distribute this solution for all the crossroads in general. That will be the most global and systematic solution of the problem.

So, up to date what features characterize the problem itself and the obstacles in its solving? They are as follows:
- Low average speed of movement (throughput of streets) because of stops on crossroads with duration frequently exceeding time of travel between crossroads;
- Inapplicability of typical constructions (road junctions) because of narrowness of streets and crossroads;
- Long-term stop of movement at erection of typical constructions (underground and overground);
- Bulkiness of transport constructions for travel, if they are overground;
- Architectural discord between bulks of possible overground constructions and surrounding buildings;
- Complexity of erection and consequently singleness of application of constructions;
- High price of constructions.

And if to speak about elimination of all the specified deficiencies simultaneously, it is not possible if the existing approach to the solving of traffic jams problem in the streets of old cities is used.. Conditions of solving contradict each other physically, organizationally and economically. However, the other principle of the problem solving can be adopted, at which the listed deficiencies are eliminated all at once. For this purpose it is necessary to determine, what is the lack of today’s estimation of the essence of the traffic jams problem.

This lack is as follows. All means of transport in the streets without dividing them on types is considered as the source of jam problems and, accordingly, a technical principle of solving the problem provides passing through the additional constructions (overground and underground) also of all types of transport without exception. And for this purpose powerful and massive constructions are required.

In fact the problem is caused by the sharp growth of number of automobiles and not all the transport in general. On the contrary, the quantity of public transport (buses, trolley buses, trams) was strongly reduced. Hence, to solve the problem of traffic jams on crossroads it is enough to apply the technical compromise, that is to provide continuous and simultaneous passage through the crossroads in different directions of automobiles, small special transport and public transport only, and for the cargo and large public transport, including rail transport, the usual signaled crossroads shall be left without changes. The limiting potential of city streets is still far from being exhausted.

In other words, today's deadlock is connected not with physical impossibility of solving this problem, but with the perversity of attempts to remove it by means of typical constructions, stereotyped thoughts and projects, which are fantastic with regard to both inconsistency and expensiveness. If we change the approach to solving this problem, we will probably receive not completely ideal but, nevertheless, very simple and effective way to road harmony without physical, technical, economic and aesthetic contradictions.

***

Much things result from the change of a problem solving principle. They are the doubtless and plural advantages specified in the application for a patent for the decision of this problem, and some inevitable, but unprincipled restrictions. If the city was constructed a long time ago and intrusion of transport breaks its primary harmony, it is only possible to dream of the ideal compromise between the old and the new.. The real compromise can be achieved only within the frames of laws of nature and it is necessary to reconcile to this restriction. This compromise of simplicity, reality and technical feasibility in the big scales is just what is described further.

1. Necessity in tunnel and massive overground constructions disappears, for if only the automobile transport vehicles pass through the constructions, constructions themselves turn out to be considerably lightened.

2. Constructions above the ground become compact and occupy not all the width of the streets above traffic way, but only width of its middle traffic lanes not interfering the lane (lanes) located near the sidewalk. It looks approximately like this.

3. From items 1, 2 it follows, that:
a) Constructions will be located at a sufficient distance to buildings;
b) Their designs may be fairly open-work, light, stocky (the height of automobiles, minibuses is minor) and can be smoothly inserted in the ambient space.

At that one shall understand, that it is completely not necessary to pile up levels of constructions for all the crossed streams on any of the problem crossroads. Erection of nothing but the second level of construction will sharply change the situation on the crossroads for the most intensive stream of vehicles. Probably, it will be possible to regulate all the other streams by means of usual adjustment of the ground movement, that is by the change of intervals of traffic lights switch over. So such crossroads can look.

Colouring of openwork constructions influences the aesthetics very interestingly. They run into surrounding architecture making a single whole. Intrusion of such constructions into the aesthetics of an architectural environment (if the concept of intrusion is in general applicable here) is far and incomparably less, than it is done by advertising, which block up both streets, and facades of houses in the cities.

4. Compactness and light-weight of constructions results in the opportunity of their manufacture from the unified, assembly modules of grooved, box-like, tubular shape with round or polygonal section. Except for, probably, some separate elements of interface of designs.

5. From item 4 it follows, that the finished construction does not require foundation works and other earth excavations which would result in a stop of movement. Here it is possible to apply point foundation and support elements, which can be installed at night or during weekend without a stop of the day time traffic. At that support elements may be located not directly under constructions. They can be at a distance from them and serve as support for crossbars, farms, on which travel elements of constructions are installed.

6. From items 4, 5 it follows, that the whole construction (or its any independent and finished part of any separate overpass *) can be assembled and simply put on a crossroads at night or during weekend without a stop of the day time traffic. From this it also follows, that the number of overpasses (lanes) is not a constant value as it is typical of standard designs. If required the new ones can be erected along with the existing lanes or can be dismantled easily.

7. From items 1-6 it follows, that this is a new type of transport constructions, which can be manufactured on the line as the unified modules, from which it is possible to make up the constructions simultaneously for numbers of crossroads of various configuration. That is to build not individual constructions, but the row of constructions along the streets and highways.

8. As to the technical essence of the offered solutions, they are bridge designs. Hence, they can be supported in the required condition by means of columns, foundations or arches with its base fixed in the ground and by means of cable-stayed way, that is suspension by means of chains, hawsers, cores on towers, pylons, girders and so forth.

9. Temporary overpass constructions can be produced. They can be applied to travel above the place of local road repair or at any works on distribution pipelines, which require opening of roadbed. Such designs can be not only modular, but also mobile, if installed on the wheel or tracked chassis for the purpose of transportation.

*”Overpasses” stands for the elements of the construction of crossroads junction itself only and no other elements.

Comparison table

Parameter	Compromise junction	Typical junction	Underground junction
Simultaneous movement in different directions	+	+	+
Nonintersecting streams of automobiles	+	+/-	+/-
Nonintersecting streams of trucks	-	+/-	+/-
Compactness, light-weight	+	-	-
Applicability for narrow streets	+	-	-
Mobility, modularity, commonality	+	-	-
Admission of any transport	+	+	+/-
Traffic is not stopped during erection	+	-	-
Low cost	+	-	-
Absence of size restrictions to the admitted transport	+	+	-
Matching with surrounding architecture	+	-	+
Flow-line production	+	-	-

***

Thus, the technical solution of the problem consists in the erection above the crossroads of multilevel (as many levels as you wish) constructions for admission of automobiles only. Thus the existing ground level emains untouched.

Despite of inevitable restriction of a vertical size of transport for travel under constructions, it is possible to pass through the crossroads the vehicles with higher vertical size, than the height of a construction. It is a question of maneuver. High vehicle turns on the crossroads to the right, then turns back and having gone round perpendicular overpasses it again turns to the right on the crossroads.

However, sometimes the necessity of travel and transportation of very bulky vehicles and cargoes through the streets arises.. It can be the big truck crane or the tower crane delivered on a building site, etc. Cargoes, which can prevent movement, are usually transported at night. But here the question is not in the stop of movement but in the junction constructions, which prevent transportation of cargo.

In this case it is necessary to remember, that the design of the construction is modular. It can be quickly and easily split, shifted or raised as a leaf bridge to pass the cargo and without problems returned to the initial state. Certainly, it is possible to build on some crossroads autonomously movable, i.e. rotating or rising constructions controlled by their own mechanisms, if high vehicles go through this crossroads quite often. Actuators, elements of devices can be of mechanical, electric, internal combustion, hydraulic, pneumatic type, etc.

Model preferable parameters of constructions of the new type are as follows:
- Angle of inclination of ascent and descent is of 12-15 degrees;
- Height of the arch of the 2nd level is of 4-4.5 meters;
- Height of the arch of the 3rd level is of 6.5-7 meters;
- The distributed average load on the arch without columns at its length of 100 meters is 40-50 tons if it is possible.

Thus, it turns out, that the scope of the automobile transport continuously passing through the separate central lanes of the street bridge can absorb all automobile transport which now occupies the whole width of the street. Lanes at sidewalk will be unloaded for public transport, bicyclists.
It shall be taken into account that installation of junctions of new type should not be started with city centre, if the problem of jams has not local, but system, scale character. Unloading of highways, streets should be started with periphery of problem zones, territories.