DE102005032975A1 - Dynamic road traffic management system responds to a disturbance and uses modelling system to determine traffic control changes - Google Patents

Abstract

A road traffic management system [3] responds to a disturbance [S] in traffic movement along a road network. The system provides a dynamic evaluation of the system and generates a prediction of effect using a modelling system. This then generates a suitable change in the control of traffic using the light signalling [S1,S2] to re-route vehicles.

Description

The The invention relates to a method for calculating an estimate of the current traffic status and / or a forecast of a future traffic condition in a road network, whereby in the calculation a disturbance in the road network considered becomes. The invention further relates to a traffic computer for one Traffic management center for calculating a current or future Traffic condition in a road network.

The Responsible for The traffic is daily growing demands on traffic engineering and traffic telematics faced. An important task of modern systems is this securing individual mobility among the simultaneous Attention to environmental aspects. Parent traffic management systems become more and more important. The data about burdens of transport networks This is becoming increasingly important.

One important starting point is the reduction and relocation of traffic. This especially applies to the case that in a road network, for example, in an urban road network or in a highway network, an incident occurs, for example caused by a traffic accident or by any other conditional or complete partial road closure, for example due to a construction project or a bad weather event. In such an accident, the capacity of a sinks so-called links in the network, so about a road between two network nodes or crossings, from a maximum value to a reduced value (partially locked Street) or to zero (fully closed road).

Of the Invention is based on the object, a method and a traffic computer specify with which the accuracy of the calculation of a current or a future one Traffic condition is improved when a fault occurs.

These The object is based on the aforementioned method according to the invention solved by that the disorder in the road network so considered that will be a time delay between an occurrence, a change and / or a cancellation of the incident until receipt of appropriate information by the road user is included in the calculation.

Of the Inventor has realized that it is for the calculation of traffic conditions is important to consider that an actual Traffic system re the responsiveness of its road users a certain inertia has, for example, 15 to 90 minutes. This has its cause Above all, not all road users are immediately informed about accidents or accidents Blockages are taught and usually takes some time to pass the information - mostly via radio or corresponding signaling devices passed - at the Road users. Such inertia often causes larger backwater effects, which are over an environment of the accident can spread. With the method according to the invention is a corresponding dynamic Modeling the accident considering this inertia possible.

To In a preferred embodiment, a first time delay flows from Occurrence of the disorder until receipt of information about the occurrence of the fault and a second time delay from the suspension of the incident until receipt of information about the cancellation of the fault in the calculation.

The disorder is preferably as a time course of a reduced capacity of Links considered. The capacity for example, as a number of across a street or given a link passable vehicles per unit time.

To a particularly preferred embodiment is as a time course a continuous first course of capacity used. Jumps in the capacity course are avoided because they - because the inertia described above not included is not correspond to the real state of knowledge of the participants. At the first Change course the capacity values not leaps, but gradually. Take, for example she after the occurrence of the disorder linear from and after the cancellation of the disturbance again linearly on the original Value too.

Especially indicates the first course after occurrence, change or cancellation the disorder each a delay time range with decreasing, changing or increasing capacity on.

The Length of the delay range and thus, for example, the slopes in the arrival or descent of the capacity can depending on the type of fault be different: In an accident, they are approximately in the area between 5 and 360 minutes, preferably in the range of 15 to 90 minutes, in the case of a construction site quite in the range of a few days.

According to a very particularly preferred development is in the method according to the invention as a time course, a leaky or used faster than the first course varying second course of capacity. Preferably, the accident is modeled in the calculation method in two different ways, namely as a continuous first course and as a sudden or faster varying second course.

• a) eine Routenwahlberechnung zur Berechnung der aktuell von den Verkehrsteilnehmern ausgewählten Fahrrouten, wobei von den an bestimmten Stellen gemessenen tatsächlichen Verkehrsdaten ausgegangen wird, und
• b) ein Verkehrssimulationsmodell zur Berechnung der zeitlichen Entwicklung des Verkehrszustandes.

The computing method for calculating the traffic condition comprises, according to a particularly preferred embodiment, the following computation methods communicating with each other:

• a) a route selection calculation for the calculation of the currently selected by the road users driving routes, which is based on the measured at specific locations actual traffic data, and
• b) a traffic simulation model for calculating the temporal evolution of the traffic condition.

Next These cooperating process components may contain other components be. The traffic model can be in the form of a microscopic example or macroscopic traffic simulation and the Illustration of the dynamics of traffic in the road network accomplish, for example, for a short-term dynamics of a current state or for a longer term Forecast.

To In a very particularly preferred embodiment, the fault is added the route selection calculation with the first course taken into account. In this lies the realization that the driver made their decision taken route only then change if they have the appropriate error message have received. This is not only true for short-term accidents, but on a longer one Timescale of several days even when setting up or cancellation from construction sites. By using the first gradient in the Route selection calculation method can the Routenwahl- and possibly Verkehrsumlegungsverfahren be considered as a dynamic process because it is dynamic Effects of the accident, for example, due to the time delay backflow effects, in the flow of traffic. Such a dynamic route selection calculation method performs as Calculation result even only to gradually reorienting routes, which is the slowly increasing level of information of road users correctly reflected.

To In another particularly preferred embodiment, the disorder is added taken into account in the traffic simulation model with the second course of the capacity. The component "traffic model" becomes capacity changes as a result of a fault ie directly or without delay effective. This is based on the knowledge of the inventor, which requires a high-precision calculation the traffic condition in the traffic model the physical reality, e.g. a closed road, immediately and without delay must be reflected, because it is here - im Contrary to the route selection calculation method - not to the degree of information the road user arrives.

The The object mentioned above is based on the aforementioned Traffic computer according to the invention, solved by input means for inputting a time delay and / or a memory for storing predefined time delays, wherein the traffic computer is programmed such that the time delay (EN) for replication a real time delay between an occurrence, a change and / or a suspension of a disturbance in the road network until receipt of appropriate information in a road user usable is.

An embodiment of a method and a traffic computer according to the invention are described below with reference to 1 and 2 explained in more detail. Show it:

1 a road network with a traffic computer for calculating a traffic condition of the road network, and

2 a schematic representation of the modeling of a in the road network of 1 occurred accident with the method according to the invention.

1 shows a road network 1 with several intersections or network nodes NK1, NK2, to each of which a schematically illustrated signaling system S1, S2 is installed. At measuring points M1, M2, M3, the traffic volume and the speed of the vehicles are measured by means of detectors. The corresponding detector data D are via wired or wireless data links of a traffic management center 3 which calculates from these starting a current traffic condition and its temporal evolution. As a measure for the resolution or avoidance of detected or predicted unfavorable traffic conditions, for example a traffic jam as a result of a traffic that is greatly increased on a link L _i , the traffic management center intervenes 3 via the signal systems S1, S2 in the traffic.

For a highly accurate estimation of traffic conditions in the road network 1 According to one finding of the inventor, the proper treatment of a disorder S is important. Such a disturbance S is in 1 by way of example on a street or a link L _{i represented} by index i. The information about such an accident or a malfunction S usually arrives at the traffic center by telephone calls of the road users or radio conversations of the police authorities 3 so that the disturbance S in the traffic condition calculation system formed there 10 with his traffic computer 11 can be taken into account.

The traffic condition calculation system 10 in which the calculation method according to the invention is implemented is in 2 shown in detail. It includes a traffic simulation model 12 as well as a traffic situation calculation module 14 , which in turn is a route selection calculation module 16 as well as a traffic allocation module 18 includes.

The Traffic simulation model works on the principle of movement of individual vehicles that follow macroscopic laws.

The traffic condition calculation system 10 estimates the current traffic situation based on a dynamic route selection and traffic allocation model. The calculation is based on the detector data D, on target functions Z (eg system, user optimum), traffic demand matrices, as well as on the traffic computer 11 storable topology data T (traffic parameters) over the road network 1 ,

In the route selection calculation module 16 a method is used which is based on an iteratively applied equilibrium shift. The controlling size of the iteration process are path resistances. The iterative process is followed in the traffic transfer module 18 a so-called dynamic metric propagation, which serves at the individual points in the road network 1 measured values of traffic intensity and speed on the entire road network 1 to extrapolate.

The route calculation module 16 As a result, route data R is supplied via routes R1, R2 (see FIG 1 ) on which the demand in the road network 1 currently being processed and their mean static load. The route data R becomes the traffic simulation model 12 provided. This provides data on a current traffic condition V _act to the route selection calculation module 16 ,

As a result, the traffic condition calculation system provides 10 an estimate of the current traffic conditions in the road network and its dynamic development on a short-term or long-term basis, ie estimates for future traffic conditions. All traffic conditions are on a display device 20 ( 2 ), which in the traffic management center 3 ( 1 ) is arranged, graphically displayed.

• a) Im Routenwahlberechnungsmodul 16 wird der Störfall S mit einem ersten Verlauf 22 der Kapazität K_i modelliert, der einen allmählichen Übergang von der maximalen Kapazität K_i,max zur verminderten Kapazität K_i,s im Störungsfall und umgekehrt aufweist. Die modellierte Kapazität K_i folgt der tatsächlichen Kapazität K_i mit einer ersten Zeitverzögerung Δt₁ nach dem Zeitpunkt t_s des Auftretens der Störung S und mit einer zweiten Zeitverzögerung Δt₂ nach dem Zeitpunkt t_A der Aufhebung der Störung S. Dies spiegelt den nur langsam zunehmenden Informationsgrad der Verkehrsteilnehmer nach Auftreten oder Aufhebung einer Störung wieder. Das Routenwahlberechnungsmodul 16 berechnet folglich sich nur allmählich dynamisch umorientierende Routen R₁, R₂.
• b) In dem Verkehrssimulationsmodell 12, welches die tatsächliche Dynamik des Verkehrsgeschehens im Netz abbilden soll, wird der Verlauf der Kapazität K_i über der Zeit t verzögerungsfrei mit einem stufenförmigen und sprunghaften zweiten Verlauf 24 modelliert. Der zweite Verlauf 24 spiegelt den tatsächlichen Kapazitätsverlauf wieder.

The in 1 illustrated fault S is in the traffic condition calculation system 10 modeled on two different types. These differ in the manner of modeling the time course of the so-called capacity K _{i of} the network link L _i , measured in number of motor vehicles per hour, which describes the instantaneous maximum passability of the link L _i . In the case of the fault S, ie in the event of an accident, a construction site or a blockage, the capacity K _{i is} reduced over time t. The capacity K _{i of} the left L _i decreases from a value of undisturbed maximum capacity K _{i, max} to a value of reduced capacity K _{i, s} in the event of a fault S. The reduced capacity K _{i, s} prevails at the link L _i from the time t _s of Occurrence of the disturbance S until the time t _{A of} the cancellation of the disturbance S. The two different types of modeling are the following:

• a) In the route selection calculation module 16 the accident S becomes a first course 22 the capacity K _i , which has a gradual transition from the maximum capacity K _{i, max} to the reduced capacity K _{i, s} in the event of failure and vice versa. The modeled capacitance K _i follows the actual capacitance K _i with a first time delay Δt ₁ after the instant t _{s of} the occurrence of the disturbance S and with a second time delay Δt ₂ after the instant t _{A of} the cancellation of the disturbance S. This only reflects this slowly increasing degree of information of road users after occurrence or cancellation of a disorder again. The route selection calculation module 16 therefore calculated only gradually dynamically reorienting routes R ₁ , R ₂ .
• b) In the traffic simulation model 12 , which is to map the actual dynamics of the traffic in the network, the course of the capacity K _i over the time t is delay-free with a step-like and erratic second course 24 modeled. The second course 24 reflects the actual course of capacity.

Instead of the first course 22 in 2 shown linear ramps in the range of time delays .DELTA.t ₁ , .DELTA.t ₂ smooth or continuously differentiable waveforms are possible. In the case of a very short fault S, it is also possible that in the first course 22 the capacity K _{i, s} in the case of failure is not reached, and / or results in the case of the linear course, for example, a V-shaped profile.

Essential to the invention is the special treatment of the time course of the capacity K _{i of} the disturbed link L _i in the road network 1 with regard to their use in dynamic route selection and traffic transfer procedures. To the inertia of the real system, ie the road users, the affected capacity values are not changed abruptly but gradually, so that the calculated route changes are first minimal and later more comprehensive. These slow changes are applied both to the initial reduction of the capacity K _i and to the later restoration of the capacity K _i .

As soon as the message about the incident S in the traffic management center 3 comes in, the disturbance S in the local traffic computer 11 detected accordingly by the local operating personnel. For this purpose, the operators have corresponding input means 11B (please refer 1 ), for example a specially programmed input mask with input fields for inputting the time delays Δt ₁ , Δt ₂ . Alternatively or additionally, the operator are doing on the input mask in a memory 11A ( 1 ) stored empirical values for different accident types (light accident, severe accident, small construction site, large construction site, fallen tree, water pipe break, etc.), for example in the form of a pull-down menu, offered. Alternatively, only the fault type is entered and the traffic computer 11 gets corresponding empirical values from the memory 11A ,

Claims (11)

Method for calculating an estimate of the current traffic condition and / or a prognosis of a future traffic condition in a road network ( 1 ), whereby in the calculation a disturbance (S) in the road network ( 1 ) is taken into account in such a way that a time delay between an occurrence, a change and / or a cancellation of the disturbance (S) until the receipt of corresponding information is incorporated in the road user. A method according to claim 1, wherein a first time delay (Δt ₁ ) from the occurrence of the disturbance (S) to the receipt of information about the occurrence of the disturbance (S) and a second time delay (Δt ₂ ) from the cancellation of the disturbance (S) to for receiving information about the cancellation of the disturbance (S) flows. Method according to claim 1 or 2, wherein the disturbance (S) takes place as a time course ( 22 . 24 ) of a reduced capacity (K _i ) of a link (L _i ) is taken into account. Method according to Claim 3, in which the time profile is a continuous first course ( 22 ) of the capacity (K _i ) is used. The method of claim 4, wherein the first course after the occurrence, the change or the cancellation of the disturbance (S) each having a delay time range (At ₁ , At ₂ ) with decreasing, changing or increasing capacity (K _i ). The method of claim 5, wherein the delay range (Δt ₁ , Δt ₂ ) has a length in the range between 5 minutes and a few days. Method according to Claim 3, in which the course of time is a sudden or faster than the first course ( 22 ) varying second course ( 24 ) of the capacity (K _i ) is used. Method according to one of Claims 1 to 7, the following communicating methods being used for calculating the traffic condition being used: a) a route selection calculation ( 16 ) for the calculation of the driving routes (R1, R2) currently selected by the road users, assuming the actual traffic data measured at certain measuring points (M1, M2, M3, ...), and b) a traffic simulation model ( 12 ) for calculating the temporal evolution of the traffic condition. Method according to claim 8 and claim 4, 5 or 6, wherein the interference (S) in the route selection calculation ( 16 ) with the first course ( 22 ) of the capacity (K _i ) is taken into account. Method according to claim 8 or 9 and claim 7, wherein the interference (S) in the traffic simulation model ( 12 ) with the second course ( 24 ) of the capacity (K _i ) is taken into account. Traffic computer ( 11 ) for a traffic management center ( 3 ) for calculating a current or future traffic condition in a road network ( 1 ) with input means ( 11B ) for inputting a time delay (Δt ₁ , Δt ₂ ) and / or with a memory ( 11A ) for storing predefined time delays (Δt ₁ , Δt ₂ ), wherein the traffic computer ( 11 ) is programmed such that the time delay (s) (Δt ₁ , Δt ₂ ) for simulating a real time delay between an occurrence, a change and / or a cancellation of a fault (S) in the road network ( 1 ) is usable until receipt of appropriate information in a road user.