RU2676771C2 - Automobile track - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the field of construction, namely to the design of roads. Motorway has expansion elements in the form of alternating sections of additional strips that are located on both sides along the road in places, where the transport stream passes from the free-flow phase to the synchronized one, the distance between the sections and the length of the additional bands being calculated from the condition that there is no synchronized flow in the drain.

EFFECT: technical result consists in increasing the functional efficiency, traffic safety, and technological repair.

1 cl, 2 dwg

Description

The invention relates to the field of construction, namely to the design of roads.

Known highways with expansion elements in the form of pockets for parking lots, as well as sections of additional lanes. The localization of additional lanes along the highway is tied to settlements, which, when planning two-lane, does not provide free and safe movement on the entire highway, reduces functional efficiency and makes it difficult to repair the roadbed.

The increased fleet of vehicles, the limited number of lanes for traffic (usually no more than two), the poor quality of the road surface created an acute problem associated with low traffic capacity and traffic safety.

At present, in Russia the length of federal highways alone exceeds 50 thousand km. In addition, the country runs regional routes with a total length of about 500 thousand km.

Following the global trend and taking into account the territory of Russia, it can be argued that the car fleet in the country will increase. Then the inevitable task arises of a national scale for the reconstruction of existing highways, the construction of new roads, primarily the most important for the national economy - federal ones.

The need to solve this problem is confirmed by many reasons. So, 62% of Russian roads do not meet regulatory transport requirements, only 8% of federal roads have a multi-lane carriageway. The transport component in the cost of production in Russia reaches 20%, while in developed countries this figure is no more than 8%. In Europe, the average speed of cargo movement is 1000 km per day, in Russia - 200-300 km per day.

There can only be one way out of this situation: the reconstruction of existing roads and the construction of new ones with multi-lane traffic. First of all, it concerns federal highways. Given that the cost of road construction and reconstruction can be 5-8 million dollars per 1 km, it should be recognized that it is impossible to solve the road problem in Russia in the required volume in the coming years.

It seems that the task of increasing throughput and traffic safety, reducing transportation costs should be solved in stages. Moreover, the first stage is only the expansion of a small part of the roads, and the result of the last is multi-lane roads (due to reconstruction of all existing and construction of new ones).

Any two-lane tracks of the usual type can serve as an analogue of the invention (Reference Encyclopedia of Roads, T. 5. Designing of Roads., Fedotov GA, Pospelov PI, M .: 2007. - 815 pp.). A close analogue may be the federal highway "Baikal" (Road map. Federal highway M-53 "Baikal". Novosibirsk-Kemerovo-Krasnoyarsk-Irkutsk (1: 1000000), series: Siberian guidebook, Orient, 2013).

The disadvantage of the existing route is the low throughput, due to the fact that its main part is made of two-lane, expansion sections are found only near settlements, gas stations or parking lots.

The present invention allows to solve the problem of the gradual reconstruction of roads with increasing throughput.

The technical result is to increase functional efficiency, traffic safety, manufacturability of repairs.

The technical result is achieved by a combination of key features:

A highway with expansion elements in the form of alternating sections of additional lanes, characterized in that the sections of additional lanes are located on both sides in the direction of travel, in places where the traffic flows from the free flow phase to synchronized, while the distance between the sections and the length of the additional bands is calculated, from the condition that there is no synchronized flow phase in the drain;

In addition: additional strips are made with dividing markings or with dividing fences;

at the source of the additional lane there are traffic signs “freight traffic”, “additional lane” with an indication of its length, and before merging on a continuous lane - the sign “give way”;

in front of the additional lanes, flow intensity recorders and LED traffic signs associated with the recorders are installed with a movement change program.

The problem statement at the first stage can be formulated as follows: on the basis of mathematical modeling and experimental studies of traffic flow on a two-lane road, determine the length of each extension and the distance between the extensions, which would most likely exclude a significant decrease in the speed of the stream and the occurrence of traffic jams.

In FIG. 1 depicts options for local extensions on a two-lane highway, where a is a symmetric extension, b is asymmetric.

In FIG. 2 shows a modernized fundamental diagram with the phases of the traffic flow.

A significant role in solving the problem assigned to mathematical modeling. There are three classic approaches to solving traffic flow modeling. Microscopic models describe the effect of the previous car on the next using ordinary differential equations based on Newtonian mechanics. The following models are macroscopic. They are based on the equations of gas dynamics. Mesoscopic models are an intermediate link between the two previous models. They are based on kinetic equations of the Boltzmann type.

To solve this problem, macroscopic models should be used. In such models, the transport flow is likened to a compressible fluid with motivation, which is present, for example, in the equation of state of the transport flow (flow velocity versus density). The key concept of this is a generalized solution of the initial Cauchy problem for the conservation law describing the traffic flow.

The first macroscopic model of a single-lane traffic stream - the Lithill-Uizem-Richards (LWR) model - appeared about 60 years ago. In it, the transport flow is considered as a flow of a one-dimensional compressible fluid. The model assumes the existence of a one-to-one relationship between the speed V (t, x) and the density (linear density) p (t, x) of the flow, and the law of conservation of mass (number of cars) is also fulfilled.

For the first assumption, the condition must be satisfied:

V (t, x) = V (p (t, x)).

Moreover, the function V (ρ) must obey the condition: V '(ρ) <0. The expression q (ρ) = ρV (ρ) is usually called the fundamental (main) diagram (PD). In it q (ρ) is the intensity of the traffic flow (cars / hour), ρ is the density (linear) of the flow (cars / km).

The second assumption is expressed by the conservation law:

.

.

Numerous works, especially in recent years, which relate to the fundamental diagram of the traffic flow, which describes the dependence of the flux density on its intensity in a certain section of the road, allow us to conclude that at low and very high densities there is a correlation between flow and density. For intermediate densities of a certain branch, a region of uncertainty arises in the fundamental diagram due to the strong dependence on the specifics of the road network (Fig. 2). Many attempts have been made to explain these features (“about the inversion of the -λ form of the fundamental diagram”, “hysteresis”, “catastrophe theory”, “drop in throughput”, etc.), which indicate the possibility of the existence of supercritical flows. In the theory of traffic flows, PD is given exclusively significance. At the same time, FD is a kind of stumbling block for the whole theory of traffic flows. This is due to the fact that in the LWR model (and many other PD-based models) the diagram, i.e. the function q = f (ρ) is taken smooth (i.e., differentiable). If it is built on the basis of experimental data, then in the region of average density values a “cloud” forms, which is not approximated by any curve, i.e. the dependences q = f (ρ) actually accepted in macromodels of the LWR type do not exist.

To solve this problem, attention should be paid to research related to the influence of the geometry of the road “expansion-contraction” on the PD decisions. when one lane at first expands to two, and then (after a certain interval in length) two lanes narrow to one.

The decrease in traffic capacity is associated with the occurrence of congestion in the stream. The analysis of empirical data allows you to build the following scenarios of congestion under conditions:

Driving congestion does not occur in the free flow with a gradual increase in flow. A significant likelihood of plugs during the phase transition from free flow to synchronized (Fig. 2).

With a sufficiently small amount of traffic flow, the speed of cars in the synchronized phase (higher in traffic flow) is relatively high. Moving traffic jams in such a flow do not occur. If the initial value of the flow is high, then the speed of the cars is low, and then, as a rule, congestion (traffic jams) occur in the synchronized flow.

The lower the speed of movement in the synchronized stream, the more likely traffic jams occur in it. This means that the frequency of occurrence of moving plugs increases to the maximum possible values of the input stream. Flow states with a high density and low speed of movement in which moving plugs do not occur are not observed in a synchronized flow.

We give a classification of the phases of the flow.

Free flow. While the road is not busy, drivers adhere to a constant speed, freely passing (if available) to neighboring lanes. At this stage, cars are comparable to the flow of free particles.

Synchronized stream. The road becomes crowded, drivers lose the ability to freely maneuver, and are forced to coordinate their speed with the flow rate. This stage is similar to fluid flow.

Start - stop motion. With a large accumulation of cars, the flow movement becomes intermittent. At this stage, the traffic flow can be compared with the crystallization of water, cars become “glued” to a given point of the road for some period of time.

Wide moving traffic jams. In this phase, cars (car groups - clusters) are like pieces of ice moving in a fluid stream. All four phases are shown in FIG. 2. The first part of the problem should be solved on the basis of the condition p≤p _max (Fig. 2). If this condition is met, traffic jams are unlikely to occur in the free stream, and the speed of the cars will be practically limited by the rules of the road and the quality of the road.

On road sections where p> p _max , the traffic flows from the free flow phase to the synchronized one, and there is a high probability of traffic jams (for the reliability of the solution, a continuous separation of two oncoming traffic lanes is assumed). In these places, to ensure high traffic capacity of the road, it is necessary to expand the road to two lanes in one direction (Fig. 1).

The length of the additional lane must satisfy the ratio at which p = k * p _max (k <1). The specific value of k must be determined for each section of the road under consideration.

At the end of the additional lane, the road narrows. For a traffic stream that can be described by a narrowing model on the road, the most difficult part will be the transition from two lanes to one, the so-called “bottleneck” (runoff).

, по дополнительной полосе движения.For the purpose of efficiency of the additional lane, the traffic flow at its outlet (runoff) should be sorted and made more homogeneous. To do this, using the appropriate traffic signs and the latest means of monitoring the movement of each car (for example, the Plato system), you should start up all slowly moving vehicles, as well as category cars

, in an additional lane.

In the present invention, at the source of the additional lane there are traffic signs “freight traffic”, “additional lane” with an indication of its length, and before merging on a continuous lane - the sign “give way”, which will not accumulate on the additional lane of freight transport. It is possible, for example, at night, to reduce the flow rate, turn off the “freight traffic” sign, using an intensity recorder in front of the additional lane associated with LED traffic signs with a traffic change program.

The present invention also provides a device for additional lanes on the left side of the vehicle, which allows them to be used as faster, which increases the throughput of the route, while the bending of the route will be insignificant, and for traffic safety, the additional lanes will be equipped with dividing barriers.

The functional efficiency of local expansion (an additional short lane) is manifested in the fact that traffic jams are excluded both in the main lane and in the drainage zone (bottle neck) of the traffic flow from the expansion lane to the main lane of the highway, thus increasing the throughput of the highway . Traffic safety is enhanced by significantly reducing or eliminating overtaking in the oncoming lane. When repairing the main lanes, the direction of the traffic flow through additional lanes is possible.

Thus, the present invention, at lower cost, can increase throughput on two-lane and single-lane routes and solve the problem of gradual reconstruction.

Claims (1)

A highway with expansion elements in the form of alternating sections of additional lanes, characterized in that the sections of additional lanes are located on both sides in the direction where the traffic flows from the free flow phase to synchronized, while the distance between the sections and the length of the additional lanes is calculated from the condition that there is no synchronized flow phase in the drain.

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