EP1528524A2 - Method for traffic prognosis based on historical data - Google Patents

Abstract

Process for traffic prognosis comprises constructing a database using an aggregation of all traffic patterns at permanently effective bottlenecks. On identification of a new, temporarily effective bottleneck an aggregated traffic pattern is determined and the database is updated. A specific travel time is assigned to each aggregated traffic pattern. The traffic prognosis is prepared by determining and displaying travel times for all or one part of the section of the traffic network taking into account the travel times assigned to the aggregated traffic patterns of the updated database.

Description

The invention relates to a method for gangway-based Traffic forecast according to the preamble of the claim 1. This procedure becomes a hydrograph database taking into account patterns dense traffic effective bottlenecks of a considered traffic route network constructed, and traffic forecasts are using current traffic measurements and comparing them with data created from the hydrograph database.

Such traffic forecasting methods are in different previous patent applications of the Applicant on this subject see, for example, DE 100 62 856 A1, DE 100 57 796 A1 and the older German patent application 103 36 590.7. As there and for example in DE 199 44 075 A1 described in detail, the dynamics of dense Traffic at the so-called effective bottlenecks of a considered Traffic network, e.g. a road network, within a considered area, through education and describe the behavior of the so-called patterns of dense traffic, in the present case also called traffic pattern. Such Patterns of dense traffic consist of the distinguishable state phases "synchronized traffic", "compressed synchronized Traffic "and" moving wide traffic jams ", with the traffic dynamics with additional consideration adequately describe the state of "free traffic" leaves.

In DE 197 53 034 A1 a method for gangway-based Traffic forecast described in which a hydrograph database Based on traffic data is built, the come from multiple data sources, such as fixed detectors and in-motion sampling vehicles, so-called FCD vehicles. To the prognosis becomes by a probabilistic selection a most likely hydrograph selected.

In most cases, the conventional gang-based forecasting methods work on the basis of stationary vehicle counting stations and other means of measuring traffic flows, which are then in mean speeds and travel times required be converted. Investigations show that these Although method with free-flowing traffic usually satisfactory Results, since in this case the traffic flow via the so-called fundamental diagram a medium speed can be clearly assigned. On the other hand is the reliability of this method is limited when states dense traffic. These may vary depending on the other circumstances different from those mentioned above, individualizable states "synchronized traffic", "compressed synchronized traffic" and "moving wide traffic jams "with the same traffic flow are the mean speed and travel time strongly dependent on which of these dense traffic conditions see the journal articles B.S. Kerner and P. Konhäuser, Phys. Rev. E, 48, p. R2335, 1993 and Phys. Rev. E, 50, p. 54, 1994 and B.S. Kerner and H. Rehborn, Phys. Rev. E, 53, p. 1297, 1996.

Although it can be thought of as a remedy, instead of the Measurement of traffic flows and the estimation based on them the medium speeds and travel times one direct measurement of travel times independent of traffic flows for example by FCD vehicles. This approach will work with fixed transport infrastructure often work well but encounter difficulties with changes in infrastructure, e.g. at new arising construction sites and other temporary effective Constrictions. Because a forecast of travel time increase by a newly created construction site requires this method new, time-consuming travel time measurements on different days through FCD vehicles, so that way travel time-line forecasts not within a short time after setup a construction site can be created.

The invention is the provision as a technical problem a method of the type mentioned, with the traffic-based traffic forecasts comparatively Reliable creation, even with temporary occurring effective bottlenecks of the considered traffic route network.

The invention solves this problem by providing a method having the features of claim 1. In this Procedure is to build the hydrograph database one Aggregation of all traffic patterns to permanent effective Narrowing the considered traffic route network carried out. In addition, when detecting a newly occurring temporary effective Bottleneck an associated aggregated traffic pattern determined and the hydrograph database with this updated. Each aggregated traffic pattern becomes a specific one Travel time associated, and to create the traffic forecasts travel times are based on this basis all or a selectable part of the legs of the considered and displayed network.

Consequently, according to the invention, traffic patterns that are based on the composition the different individualizable states dense traffic based, the basic building blocks of a aggregated hydrograph forecast. The invention makes use of the knowledge that any such traffic pattern at an effective Bottleneck a certain travel time increase in comparison can be assigned to the state of free traffic. Therefore, track-related travel times, especially for passing effective bottlenecks, directly and automatically from the traffic patterns in the hydrograph database. In the case of a newly occurring, temporary effective Bottleneck, like a construction site, this can relatively quickly certain traffic patterns are assigned when the traffic flows in the area of this temporary effective bottleneck are detectable.

In one embodiment of the invention according to claim 2 is the Influence of a traffic pattern that has a newly occurred, temporary effective bottleneck is assigned to the other Traffic patterns upstream and downstream of the new temporary effective bottleneck in the update the hydrograph database predicts and takes into account. This allows the accuracy of the gangway-based Increase traffic forecast further.

In a further embodiment of the invention according to claim 3 Traffic pattern and travel time data during an update the hydrograph database due to a recent, automatically determines the temporary effective bottleneck, and the automatically generated hydrographs in this way upon cancellation of the temporary effective bottleneck automatically deleted again. This makes the influence more effective temporarily Bottlenecks on the traffic situation in the gangway-based Traffic forecast relatively fast and limited taken into account for the duration of the existence of this bottleneck become.

A development of the invention according to claim 5 provides advantageous Possibilities of displaying the predicted traffic condition for the user, in particular a driver, in front.

Fig. 1

eine schematische Darstellung eines ersten, verfahrensgemäß zur gangliniengestützten Verkehrsprognose und insbesondere zur Reisezeitprognose im Bereich effektiver Engstellen benutzten aggregierten Verkehrsmusters aus synchronisiertem Verkehr und gestauchtem synchronisiertem Verkehr,

Fig. 2

eine Darstellung entsprechend Fig. 1 für ein zweites aggregiertes Verkehrsmuster aus synchronisiertem Verkehr, gestauchtem synchronisiertem Verkehr und sich bewegenden breiten Staus,

Fig. 3

eine Darstellung entsprechend Fig. 1, jedoch für ein weiteres aggregiertes Verkehrsmuster in Form eines übergreifenden Musters über mehrere Engstellen aus synchronisiertem Verkehr und gestauchtem synchronisiertem Verkehr und

Fig. 4

eine Darstellung entsprechend Fig. 3, jedoch für ein viertes aggregiertes Verkehrsmuster in Form eines übergreifenden Musters über mehrere Engstellen aus synchronisiertem Verkehr, gestauchtem synchronisiertem Verkehr und sich bewegenden breiten Staus.

Advantageous embodiments of the invention are illustrated in the drawings and will be described below. Hereby show:

Fig. 1

a schematic representation of a first, according to the method of traffic-based traffic forecast and in particular for travel time forecast in the area of effective bottlenecks used aggregated traffic pattern of synchronized traffic and compressed synchronized traffic,

Fig. 2

1 for a second aggregated traffic pattern of synchronized traffic, compressed synchronized traffic and moving wide congestion,

Fig. 3

a representation corresponding to FIG. 1, but for a further aggregated traffic pattern in the form of an overlapping pattern over several constrictions of synchronized traffic and compressed synchronized traffic and

Fig. 4

a representation corresponding to FIG. 3, but for a fourth aggregated traffic pattern in the form of a cross-pattern over several bottlenecks of synchronized traffic, compressed synchronized traffic and moving wide traffic jams.

The present method makes the traffic-based traffic forecast from aggregated traffic patterns to permanent ones and temporary effective bottlenecks of a considered traffic route network Use. On some essential traffic patterns will be discussed in more detail below with reference to the figures. Any suitable suitable methods for carrying out the process Means as they are in the use of the specialist for this purpose are and therefore need no further explanation. It can in particular on the above-mentioned publications and the references cited there are referenced.

According to the method initially to build a hydrograph database obtained the required input data and to corresponding traffic measurements, for example about traffic volume, Cruise speeds and travel times for a considered Traffic route network, for example a road network in a particular area. It will be in the field of permanent effective bottlenecks of the traffic route network Traffic patterns resulting from the individualizable dense Traffic conditions "synchronized traffic", "compressed synchronized traffic "and" moving wide traffic jams " composed, determined and as basic building blocks of a aggregated hydrograph forecast used.

For this purpose, an aggregation of all traffic patterns every effective bottleneck in the network of traffic routes, and each aggregated traffic pattern becomes a travel time or a travel time increase in comparison with the travel time in Condition assigned to free traffic. In addition, when detecting a newly occurring, temporary effective Bottleneck, for example, when receiving a message about a newly built construction site or a longer-lasting accident site, this temporary effective bottleneck a corresponding associated traffic pattern and the influence this traffic pattern on the other traffic patterns upstream and downstream of the new temporary effective Bottleneck predicts.

With this information, the hydrograph database will be respectively automatically updated, i. it will automatically become hydrographs belonging to the new temporary effective bottleneck for said traffic patterns and associated travel times generated and managed in the hydrograph database. This preferably also includes a prognosis of the influence of the Traffic pattern of new temporary effective bottleneck the other traffic patterns in the hydrograph database of permanent or current temporary bottlenecks upstream and downstream of the new bottleneck. Furthermore is preferably provided that in the manner described automatically generated hydrographs of the particular traffic pattern a newly occurred, temporary effective bottleneck be automatically deleted again in the hydrograph database, as soon as this bottleneck no longer exists, for example when a new construction site was lifted again.

Another option is the aggregated traffic patterns to build the appropriate hydrograph database or the corresponding traffic pattern-based hydrograph forecasts together with automatically for example one of Central generated traffic reports, especially those on RDS / TMC basis, process and such interaction of traffic reports, such as RDS / TMC messages, and aggregated Traffic patterns also for updating care to use the hydrograph database.

The on the basis of traffic patterns at effective bottlenecks created hydrograph database then forms part of a appropriate baseline traffic prediction system, in which a comparison of current traffic measurements with the stored hydrographs a best fitting hydrograph according to one of the skilled artisan algorithms is selected. Optionally, a database for the mentioned traffic reports, for example in RDS / TMC format be provided. The representative patterns are dense Traffic at effective bottlenecks can also be after one the algorithms known from suitable traffic measurement data determined and in their temporal / local course be predicted.

By a conventional visualization system become the user the results of the gang-based traffic forecast displayed in the desired manner, for example as a textual and / or graphical display of current and / or future Traffic disruption on a screen. In particular, can this as a graphical and / or textual display of traffic information over the temporal and local course of the aggregated Traffic patterns of effective bottlenecks on one digital Wegetzkarte done, for example in the form of current and future travel loss times due to the pattern of dense traffic at the relevant effective Bottleneck to be predicted. Instead of or in addition to Loss can also be the current or future Travel time for relevant sections textually and / or graphically represented on the digital road network map become. Another display option is to use the temporal and local course of the aggregated traffic patterns in the form of current and future aggregated Symbols textual and / or graphic on a map for appropriate Play back sections. For example The aggregated symbols can be states with dense traffic by "congestion" and "slow-moving traffic" or by "high traffic" Danger of congestion "," medium congestion risk "and" low risk of congestion " or different by other such classifications Show.

In the figures 1 to 4 are illustrative representative Types of aggregated traffic patterns shown from the customizable dense traffic conditions "synchronized Traffic "," compressed synchronized traffic "and "Moving wide traffic jams" are constructed and for the invention Processes are used, in particular for rapid gangline-based, prognostic identification of Travel times on sections with permanent and / or temporary effective bottlenecks.

Specifically, FIG. 1 shows a first possible aggregate traffic pattern composed of an area B _{S of} synchronized traffic and an upstream area B _{GS of} compressed synchronized traffic and may form upstream of an effective bottleneck at a route point x _{S, F.} This route point x _{S, F of} the effective bottleneck forms the boundary to a downstream area B _{F of} free traffic. The transition point between synchronized traffic and compressed synchronized traffic is denoted by x _{GS, S.} Upstream of the upstream flank x _{F, GS of} the area B _{GS of} compressed synchronized traffic, there is also a free traffic area B _F. As mentioned above and explained in detail in the literature cited above, the individual areas of free traffic B _F , synchronized traffic B _S and compressed synchronized traffic B _GS customizable traffic conditions with predictable temporal local course dar. It is also known that traffic patterns from the individualized states form dense traffic upstream of a respective effective bottleneck in a manner dependent on the conditions of the actual bottleneck and the traffic volume.

Fig. 2 shows a case in which an aggregated traffic pattern forms upstream of the location x _{S, F of} an effective bottleneck, the synchronized traffic compressed from a region B _S , a synchronized traffic compressed upstream therefrom B _GS , and an upstream region thereof B _St wide moving congestion is composed, while downstream of the effective bottleneck and upstream of the aggregated traffic pattern in turn be regions B _F free movement. The transition points between synchronized traffic B _S and compressed synchronous traffic B _GS and between the latter and the area B _St are denoted by x _{GS, S} and x _{St, GS} respectively, the upstream transit point to free traffic is denoted by x _{F, St.}

FIG. 3 shows as a further possible case of an aggregated traffic pattern used for the present method, and in particular the hydrograph database, a so-called overarching pattern, ie, extending upstream over several effective bottlenecks. Specifically, this extends over four effective bottlenecks, which lie in the direction of travel at a distance successively in the considered section of the route and whose spatial positions with x _{S, F1} , x _{S, F2} , x _{S, F3} and x _{S, F4 are} designated. Upstream and downstream of the overarching, aggregated traffic pattern, in turn, there is in each case an area B _{F of} free traffic. The overarching pattern in the example shown consists of a downstream area of synchronized traffic and an upstream area of compressed synchronized traffic.

Fig. 4 shows as a further possible example of an aggregated traffic pattern on an effective bottleneck is one which like that of Fig. 3 across four effective bottlenecks x _{S, F1,} x _{S, F2,} x _{S, F3,} x _{S, F4} extends between areas B _{F of} free traffic, and in this case from a region of synchronized traffic adjacent upstream to the most downstream effective bottleneck X _{S, F} 4, a synchronized traffic compressed upstream therefrom, and a region adjacent to this upstream region wide traffic jams.

It turns out that by the aggregation of the invention traffic information using aggregated patterns dense traffic to effective permanent and temporary Narrowing in the manner described reliable forecasts current and expected future traffic conditions with Help baseline supported travel times for the individual Track sections of a considered traffic route network can be achieved even if the traffic condition Significantly from dense traffic patterns to effective ones Bottlenecks is affected.

Claims (5)

Method for gang-based traffic forecast, in which a hydrograph database is constructed taking into account patterns of dense traffic at effective bottlenecks of a considered traffic route network, and Creating traffic forecasts using current traffic measurements and comparing them with data from the hydrograph database, characterized in that to build up the hydrograph database, an aggregation of all traffic patterns at permanent effective bottlenecks of the considered traffic route network is carried out, when a newly occurring, temporary effective bottleneck is detected, a respectively associated aggregated traffic pattern is determined and the hydrograph database is updated with it, each aggregated traffic pattern of the hydrograph database is assigned a certain travel time, and for generating the traffic forecasts travel times for all or a selectable part of the sections of the considered traffic route network, taking into account the travel times associated with the aggregated traffic patterns of the respective updated hydrography database, are determined and displayed. The method of claim 1, further
characterized in that
for updating the hydrograph database by an aggregated traffic pattern of a newly occurring temporary effective bottleneck, the impact of this aggregated traffic pattern on the other aggregated traffic patterns upstream and downstream of the emerging temporary effective bottleneck is predicted. The method of claim 1 or 2, further
characterized in that
to the aggregated traffic pattern of a newly occurring, temporary effective bottleneck for updating the hydrograph database new associated hydrographs for traffic patterns and travel times are automatically generated and stored and when canceling the newly occurred, temporary effective bottleneck automatically re-generated by their appearance hydrographs again in the Gap database to be deleted. Method according to one of claims 1 to 3, further
characterized in that
for the hydrograph database, the aggregated traffic patterns are processed together with automatically generated traffic reports. Method according to one of claims 1 to 4, further
characterized in that
the forecast data obtained from the traffic-based traffic forecast using the temporal and local course of the traffic pattern textual or graphical on a digital road network map as current and future travel times for sections and / or as current and future, caused by a particular traffic pattern travel loss times and / or in the form of the traffic classifying symbols are displayed.

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