Traffic accident impact range prediction method, device and computer storage medium

Abstract

An embodiment of the present invention discloses a method, device and computer storage medium for predicting the impact range of a traffic accident, including: obtaining the average speed of vehicles on a road section when there is no accident to obtain a first average speed; obtaining the average speed of vehicles on the road section when an accident occurs to obtain a second average speed; obtaining a speed ratio of the accident section based on the first average speed and the second average speed; when the speed ratio meets a first threshold, obtaining the average speed of each direction passing through the intersection of an upstream adjacent intersection, and determining the intersection delay value of each direction of the upstream adjacent intersection based on the average speed passing through the intersection and the average speed of each direction passing through the intersection when there is no accident; when the delay value of any intersection meets a second threshold, determining a target lane; and determining the boundary position of the accident impact based on the target lane. In this way, the scope of the road section affected by the traffic accident is determined by combining the speed ratio with the intersection delay value, thereby improving the efficiency of determining the specific impact range of the accident.

Description

Technical Field

[0001] The present invention relates to the field of transportation, and in particular to a method and device for predicting the impact range of a traffic accident, and a computer storage medium. Background Art

[0002] According to statistics from the Traffic Management Bureau of the Ministry of Public Security, as of the end of 2020, the national motor vehicle ownership reached 372 million vehicles and the number of motor vehicle drivers reached 456 million. The rapid growth in the number of motor vehicles and drivers has significantly increased road traffic pressure, resulting in a continuous increase in the accident rate. The casualties and property losses caused by traffic accidents are incalculable, especially when accidents occur on complex urban roads, congestion will quickly spread around, causing large-scale traffic congestion. Traffic congestion will not only cause road network traffic collapse, cause travel difficulties, hinder timely rescue, but also make it more likely to cause new accidents.

[0003] Numerous scholars have conducted in-depth research on the impact range of traffic accidents. Effectively assessing the impact range of traffic accidents is crucial for implementing timely rescue measures, rapidly restoring normal traffic flow, and evaluating the severity of the accident. Currently, there are two main methods for studying the impact range of traffic accidents: one based on queuing theory and the other based on fluid dynamics. The second method was proposed by Lighthill, Whitharn, and Richards in the 1850s. Subsequent scholars have referred to their contributions as the LWR model, or traffic wave model. Traffic wave theory abstracts the variations in traffic density by analogizing them to the ebb and flow of water waves, conceptualizing them as traffic waves. By analyzing the propagation speed of traffic waves, it explores the relationship between traffic flow, density, and speed, and analyzes the queuing and dissipation of vehicles. Compared to deterministic queuing theory models, traffic wave models are more realistic and are widely used in studies estimating the impact range of accidents and the length of intersection queues.

[0004] However, studies using this method to analyze vehicle queues on roads often focus on entire road sections, assuming stable upstream traffic flow and two-phase control at adjacent intersections. Alternatively, queue lengths are calculated only for single-lane roads. This approach is applicable to highways and single-lane roads. However, urban roads are crisscrossed and intersections are diverse. For a typical urban intersection with four-phase signalization, the continuous flow of traffic on the road section is interrupted, and three traffic flows are formed at each exit lane during each signal cycle: through, left, and right. The release times of these flows are controlled by the signal. Furthermore, due to the different directions of vehicle travel, the queues of vehicles on each lane of the road section also vary. While traffic wave theory has certain advantages for studying vehicle queue lengths, further research is needed to optimize and enhance it to accommodate queues on urban roads and at complex intersections.

[0005] In addition, after a traffic accident occurs on an urban road, the impact of the accident spreads in a network-like manner from the accident section to the upstream, gradually causing increased intersection delays and reduced road section operating efficiency. Calculating the accident impact range using only the traffic wave theoretical model is inefficient and complex. Other indicators should be combined to comprehensively measure the impact of the accident on the road and the spread process. Summary of the Invention

[0006] In view of this, embodiments of the present invention provide a method, device, and computer storage medium for predicting the impact range of a traffic accident, which can achieve high-precision estimation of the impact range of urban road traffic accidents.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] In a first aspect, an embodiment of the present invention provides a method for predicting the impact range of a traffic accident, the method comprising:

[0009] Obtain the average speed of vehicles on the road section when there is no accident to obtain a first average speed; obtain the average speed of vehicles on the road section when an accident occurs to obtain a second average speed;

[0010] Obtaining a speed ratio of the accident section according to the first average speed and the second average speed;

[0011] When the speed ratio meets a first threshold, obtaining an average speed of each direction passing through the intersection at an upstream adjacent intersection, and determining an intersection delay value for each direction of the upstream adjacent intersection based on the average speed of passing through the intersection and the average speed of each direction passing through the intersection when there is no accident;

[0012] When any of the intersection delay values meets a second threshold, determining a target lane;

[0013] Based on the target lane, a boundary position of the accident impact is determined.

[0014] The intersection delay value includes:

[0015]

[0016] Where, μ is the delay value s at the intersection; L cross The signalized intersection range; is the second average speed; is the first average speed.

[0017] The step of determining the boundary position of the accident impact based on the target lane includes:

[0018] The signal timing plan of the intersection corresponding to the target lane, as well as the density and flow of periodic traffic inflow and outflow of the target lane are obtained to obtain the boundary position affected by the accident.

[0019] The method further comprises:

[0020] When the speed ratio does not meet a first threshold, determining a target lane based on the accident road section;

[0021] Based on the target lane, a boundary position of the accident impact is determined.

[0022] The method further comprises:

[0023] When the delay value of any of the intersections does not meet the second threshold, determining a target lane corresponding to an upstream adjacent intersection;

[0024] Based on the target lane, a boundary position of the accident impact is determined.

[0025] Wherein, when any of the intersection delay values meets the second threshold, determining the target lane includes:

[0026] When the delay value of any of the intersections meets a second threshold, determining a speed ratio of an upstream adjacent intersection in a direction corresponding to the second threshold;

[0027] The process returns to the step of confirming whether the speed ratio satisfies the first threshold value until the target lane is determined.

[0028] In a second aspect, an embodiment of the present invention provides a traffic accident impact range prediction device, comprising:

[0029] an acquisition module, configured to acquire an average speed of vehicles on a road section when there is no accident, to obtain a first average speed; acquire an average speed of vehicles on the road section when an accident occurs, to obtain a second average speed; and acquire a speed ratio of the accident section based on the first average speed and the second average speed;

[0030] a judgment module configured to, when the speed ratio satisfies a first threshold, obtain an average speed of each direction passing through the intersection at an upstream adjacent intersection, and determine an intersection delay value for each direction of the upstream adjacent intersection based on the average speed passing through the intersection and the average speed of each direction passing through the intersection when there is no accident; and determine a target lane when any of the intersection delay values satisfies a second threshold;

[0031] A processing module is used to determine a boundary position of the accident impact based on the target lane.

[0032] In a third aspect, an embodiment of the present invention provides a traffic accident impact range prediction device, the device comprising: a processor and a memory for storing a computer program that can be run on the processor,

[0033] Wherein, when the processor is used to run the computer program, it implements the traffic accident impact range prediction method described in the first aspect.

[0034] In a fourth aspect, an embodiment of the present invention provides a computer storage medium storing a computer program, which, when executed by a processor, implements the method for predicting the impact range of a traffic accident described in the first aspect.

[0035] The traffic accident impact range prediction method, device and computer storage medium provided by the embodiment of the present invention obtain the average speed of vehicles on a road section when there is no accident to obtain a first average speed; obtain the average speed of vehicles on the road section when an accident occurs to obtain a second average speed; obtain the speed ratio of the accident section based on the first average speed and the second average speed; when the speed ratio meets a first threshold, obtain the average speed of each direction passing through the intersection of the upstream adjacent intersection, and determine the intersection delay value of each direction of the upstream adjacent intersection based on the average speed passing through the intersection and the average speed of each direction passing through the intersection when there is no accident; when any of the intersection delay values meets the second threshold, determine the target lane; and determine the accident based on the target lane. The boundary position of the impact; in this way, on the one hand, by defining the intersection delay value as the time difference between the time when vehicles pass through the intersection range after the accident and when there is no accident, the impact of the accident on the intersection can be more accurately characterized; on the other hand, by defining the speed ratio as the ratio of the vehicle speed of the road section after the accident to the vehicle speed of the road section when there is no accident, it is used to evaluate the impact of the accident on the road section and whether the impact extends from the road section to the upstream intersection. Combined with the intersection delay value, the scope of the road section affected by the traffic accident is determined, the calculation complexity is reduced, and the efficiency of determining the specific impact range of the accident is improved; further, the road is divided into sections according to the vehicle driving characteristics, and the traffic wave theory is used to calculate the queue length of a single lane. The queuing-dissipation process of each lane is accurately analyzed to determine the boundary position of the impact range of the road section accident. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart of a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the impact range of a signalized intersection according to a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of a research road section for a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of road segment division for a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0040] Figure 5 A schematic diagram of traffic wave propagation analysis at an intersection in a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0041] Figure 6 A schematic diagram of a vehicle queuing process at an intersection according to a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0042] Figure 7 A schematic diagram of determining the impact range of a traffic accident according to a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0043] Figure 8 A schematic diagram of a method for predicting the impact range of a traffic accident provided by an embodiment of the present invention;

[0044] Figure 9 A schematic diagram of the structure of a traffic accident impact range prediction device provided by an embodiment of the present invention;

[0045] Figure 10 A schematic structural diagram of another device for predicting the impact range of a traffic accident provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the relevant listed items.

[0047] See also Figure 1 , a traffic accident impact range prediction method provided by an embodiment of the present invention, the traffic accident impact range prediction method can be applied to the situation of predicting the traffic accident impact range of a road section, the traffic accident impact range prediction method can be executed by a traffic accident impact range prediction device provided by an embodiment of the present invention, the traffic accident impact range prediction device can be implemented in software and / or hardware. In specific applications, the traffic accident impact range prediction device can be a terminal such as a desktop computer, a laptop computer, a smart phone, a personal digital assistant, a tablet computer, etc. The traffic accident impact range prediction method includes the following steps:

[0048] Step S101: obtaining the average speed of vehicles on a road section when there is no accident, to obtain a first average speed; obtaining the average speed of vehicles on a road section when an accident occurs, to obtain a second average speed;

[0049] Here, the speed and time of the intersection and the road section under the accident-free state are obtained, and then the first average speed of the corresponding intersection is obtained. The first average speed here generally refers to the average speed of each intersection under the accident-free state.

[0050] Step S102: obtaining a second average speed of the accident section at time T, and obtaining a speed ratio of the accident section based on the first average speed and the second average speed;

[0051] Here, the "speed ratio" is defined to characterize the impact of traffic accidents on urban road sections. It is the ratio of the average speed of vehicles on the road section when the accident occurs to the average speed of vehicles on the road section when there is no accident, that is, the ratio of the second average speed to the first average speed. The impact of accidents on traffic changes and spreads over time. In this invention, the time interval is 2 minutes. Starting from the 0th minute, the speed ratio of the i-th time interval of a certain road section is

[0052]

[0053] Where, γ i is the speed ratio of a certain road section at the i-th time interval after the accident; is the average vehicle speed in the i-th time interval after the accident, km / s; is the average vehicle speed in the i-th time interval under normal conditions, km / s. According to the definition, after the accident occurs, in the absence of other factors, γ i ∈[0,1],γ i The smaller it is, the greater the impact of the accident on the road traffic, and vice versa.

[0054] Here, the agreed threshold γ threshold is the first threshold. In a certain interval, when the road speed ratio is less than the agreed threshold γ threshold When the first threshold is met, it is considered that the accident impact has spread from the road section to the upstream intersection.

[0055] In one embodiment, when the speed ratio does not meet a first threshold, a target lane is determined based on the accident road section; and a boundary position of the accident impact is determined based on the target lane.

[0056] That is to say, if it is greater than the agreed threshold γ threshold , that is, the first threshold is not met, it is considered that the maximum impact length of the accident on the road section does not exceed the accident section.

[0057] Step S103: When the speed ratio meets the first threshold, the average speed of each direction passing through the intersection of the upstream adjacent intersection is obtained, and the intersection delay value of each direction of the upstream adjacent intersection is determined based on the average speed of passing through the intersection and the average speed of each direction passing through the intersection when there is no accident;

[0058] Here, the intersection delay value is defined as the time difference between the time when a vehicle passes through the intersection range after an accident and when there is no accident, that is,

[0059]

[0060] Where μ is the delay at the intersection, s; L cross is the range of the signalized intersection, km; is the average speed through the intersection range under accident conditions, km / s; is the average speed across the intersection in a non-accidental state, in km / s. The larger μ is, the greater the impact of the accident on the intersection.

[0061] According to my country's urban traffic regulations, the influence range L of a signalized intersection is generally set at a distance of 140-180m. This paper selects L cross =180m, the starting point is 180 meters away from the stop line, and the end point is on the stop line.

[0062] Step S104: When any intersection delay value meets a second threshold, determining a target lane;

[0063] Here, see Figure 2 , assuming the distance between the two intersections is H. For example, the agreed threshold μ threshold is the second threshold. In a certain interval, when the intersection delay is greater than the agreed threshold μ threshold When the second threshold is met, it can be considered that the accident impact has spread from the intersection to the upstream adjacent road section.

[0064] Here, when the delay value of any of the intersections satisfies a second threshold, a speed ratio of an upstream adjacent intersection in a direction corresponding to the second threshold is determined;

[0065] And return to the step of confirming whether the speed ratio meets the first threshold until the target lane is determined.

[0066] In one embodiment, when the delay value of any intersection does not meet the second threshold, a target lane corresponding to an upstream adjacent intersection is determined; and based on the target lane, a boundary position of the accident impact is determined.

[0067] That is to say, if it is less than the agreed threshold μ threshold , that is, if the second threshold is not met, it is considered that the accident has not affected the upstream adjacent road section.

[0068] Step S105: Based on the target lane, determine the boundary position affected by the accident.

[0069] Here, after the lane is determined, the signal timing plan of the intersection corresponding to the target lane and the density and flow of periodic traffic inflow and outflow of the target lane are obtained to obtain the boundary position affected by the accident.

[0070] Here, see Figure 3 We assume that the upstream and downstream intersections of the studied road section are typical signalized intersections in the urban road system, labeled U and D, respectively. The distance between the two intersections is H. The road section consists of four lanes, with lanes counted from the inside out, with lane 1 on the innermost side and lane 4 on the outermost side. The intersection also has six dedicated lanes. Both upstream and downstream intersections are configured with four phases: east-west through, east-west left turn, north-south through, and north-south left turn. Right turns are not signalized. Right-turn traffic is often ignored in most studies due to its low volume. However, given the crisscrossing nature of urban roads, some intersections experience significant right-turn traffic, so this paper incorporates right-turn traffic into the model. In addition to right-turn traffic, two traffic flows enter the studied road section at the upstream intersection during each cycle when the east-west through signal is green and the north-south left turn signal is green. Meanwhile, two traffic flows exit the downstream intersection during each cycle when the east-west through signal is green and the east-west left turn signal is green.

[0071] The vehicle exits the upstream intersection at a certain speed, changes lanes for the first time when it reaches a certain distance from the entrance of the downstream intersection, and enters the dedicated lane when it reaches the gradient section. This paper divides the road section between intersections U and D into three sections: a, b, and c. Figure 4 As shown in Figure 2, Section a is the section between Section 2 and Section 1 where the dedicated lane is located. Vehicles cannot change lanes, and the length of Section a is the actual length of the dedicated lane. Section 2 includes two adjacent sections: one at the beginning of the dedicated lane, designated Section 21; the other at the beginning of the transition section, designated Section 22. Section b is the section between Section 3 and Section 2. Vehicles change lanes in advance in this section to prepare for entering the dedicated lane. In this paper, Section b is assumed to be 130 meters long. Section c is the remaining section between Section 4 and Section 3, representing the majority of the road under study.

[0072] In the above embodiment of the present invention, the average speed of vehicles on a road section when there is no accident is obtained to obtain a first average speed; the average speed of vehicles on the road section when an accident occurs is obtained to obtain a second average speed; the speed ratio of the accident section is obtained based on the first average speed and the second average speed; when the speed ratio meets a first threshold, the average speed of each direction passing through the intersection of the upstream adjacent intersection is obtained, and the intersection delay value of each direction of the upstream adjacent intersection is determined based on the average speed passing through the intersection and the average speed of each direction passing through the intersection when there is no accident; when any of the intersection delay values meets the second threshold, the target lane is determined; based on the target lane, the boundary position of the accident impact is determined; in this way, a On the one hand, by defining the intersection delay value as the time difference between vehicles passing through the intersection range after the accident and in the accident-free state, the impact of the accident on the intersection can be more accurately characterized; on the other hand, by defining the speed ratio as the ratio of the vehicle speed of the road section after the accident to the vehicle speed of the road section in the accident-free state, it is used to evaluate the impact of the accident on the road section and whether the impact extends from the road section to the upstream intersection. Combined with the intersection delay value, the scope of the road section affected by the traffic accident is determined, the calculation complexity is reduced, and the efficiency of determining the specific impact range of the accident is improved; further, the road is divided into sections according to the vehicle driving characteristics, and the traffic wave theory is used to calculate the queue length of a single lane. The queuing-dissipation process of each lane is accurately analyzed to determine the boundary position of the accident impact range of the road section.

[0073] Please refer again Figure 4 , take the analysis of the queue process in lane 2 as an example. Most of the vehicles queuing in lane 2 are waiting to go straight, which is mainly controlled by the east-west straight-through signal lights at intersection D. The analysis starts from the moment when the straight-through red light starts in the nth cycle, with the stop line as the queue starting point, and assuming that the queue length at this time is 0. Let and are the starting time of the red light and green light for going straight at intersection D in the nth cycle respectively. At time t, the red light of the nth cycle turns on, and the first traffic flow begins to queue in the through lane of section a, generating the first stopping wave. The stopping wave propagates upstream, and its wave speed is set to but

[0074]

[0075] Where, is the average arrival flow and density of the first traffic flow in the through lane of section a in the nth cycle, that is, the average flow and density of all dedicated through lanes passing through section 22, 0 is the stop flow, is the parking density of the through lane in section a. At time , the traffic flow queues up to section b. Since the traffic flow and density in section b are different from those in section a, a new parking wave is generated in lane 2. Let its wave speed be but

[0076]

[0077] Where, is the average arrival flow and density of the first traffic flow arriving at the second lane of section b in the nth cycle, that is, the average flow and density of the second lane of section 3, is the parking density of lane 2. time, All vehicles in state b enter the queue in section b. At time t, the second traffic flow begins to queue at the end of the second lane of section b. Let its wave speed be but

[0078]

[0079] in is the average arrival flow and density of the second traffic flow arriving at the second lane of section b in the nth cycle, that is, the average flow and density of the second lane of section 3. The vehicles coming from upstream need to turn and change lanes when entering section b, so the stopping wave speed will change when the second traffic flow queues to section c. Assume that the traffic flow The wave speed is but

[0080]

[0081] in, is the average arrival flow and density of the second traffic flow arriving at the second lane of section c in the nth cycle, that is, the stable speed and density of the traffic flow in the second lane after merging into the section from upstream. time, All vehicles in this state enter the queue.

[0082] exist At time , the nth cycle of the straight green light begins, and the straight vehicles drive out of the intersection at a certain flow rate, generating a starting wave, which propagates upstream. Let its wave speed be but

[0083]

[0084] in, It is the average flow rate and density of all through lanes of section 1 of section a for the queued vehicles. At time t, the starting wave propagates to section b. Similarly, because the flow and density of all straight lanes at exit section 1 are different from the flow and density of lane 2 at exit section 22, a new starting wave is generated in lane 2. Let its wave speed be but

[0085]

[0086] in, is the average flow rate and density of the queued vehicles leaving the second lane of section 22. When propagating to section c, a new starting wave is generated, and its wave speed is set to but

[0087]

[0088] in, The average flow rate and density of queued vehicles leaving the second lane of section 3.

[0089] Assume that the parking wave and the starting wave are When they meet, the maximum queue length is reached. According to the parking queue process, the maximum queue length is calculated as

[0090]

[0091] The formula for calculating the maximum queue length based on the start-up forward process is:

[0092]

[0093] When the two types of waves meet, a third type of wave, the evanescent wave, is generated, which propagates from the meeting point to the stopping line. Assume that the velocities of the evanescent waves generated in sections c, b, and a are All propagate toward the stop line.

[0094]

[0095]

[0096]

[0097] If not all vehicles in the queue have left the intersection when the light turns green in the nth cycle, the stranded vehicles will queue up again in the n+1th cycle.

[0098] Traffic wave analysis and queue length calculation for the n+1th signal cycle

[0099] exist At time n+1, the red light turns on in the cycle. The secondary queue parking waves generated in sections a, b, and c are Right now

[0100]

[0101]

[0102]

[0103] Located in At time , the dissipation wave and the secondary queue parking wave meet in section c, and the secondary queue is completed at this time. The length of the secondary queue is recorded as According to the convoy dissipation process, the secondary queue length is calculated as:

[0104]

[0105] According to the secondary queuing process, the secondary queue length is calculated as:

[0106]

[0107] Subsequent traffic flows follow the trajectory of each traffic wave in the nth cycle. Therefore, in the n+1th cycle, the maximum queue length of lane 2 is

[0108]

[0109] When vehicles queue in section b, they will choose different lanes to queue due to their different directions of travel; but when the queue is long, vehicles will choose to enter the lane with fewer vehicles first and then wait for an opportunity to change lanes, so the distribution of vehicles on the road section is more uniform. are the queue lengths of the four lanes in the mth signal cycle, and the maximum lane queue length is

[0110]

[0111] The average lane queue length is

[0112]

[0113] The maximum queue length of the road section is

[0114]

[0115] Analysis of the queuing process of vehicles at the intersection and the propagation of traffic waves at the intersection Figure 5 、 Figure 6 .

[0116] Please refer to Figure 7 and Figure 8 The above-mentioned traffic accident impact range prediction method is further described below through a specific embodiment.

[0117] (1) From the moment of the accident, calculate the speed ratio γ of the accident section (from the accident location to the boundary of the first upstream intersection) at a time interval of 2 minutes. i , with 80 minutes as the maximum time range limit, the speed ratio of each section can be calculated for up to 40 time intervals, that is, i = 1, 2, ..., 40. If all γ iGreater than γ threshold , go to step (4); if there is γ i Less than γ threshold When , it is considered that the impact of the accident on traffic overflows to the upstream intersection and affects the vehicle driving at the upstream intersection, and then go to step (2).

[0118] (2) Calculate the delay μ of each entrance of the upstream intersection adjacent to the road section at a 2-minute time interval. xj , x represents direction, j=1,2,...,40. Taking the west import as an example, if all μ xj Less than μ threshold , go to step (5); if there is μ xj Greater than μ threshold , it is considered that the impact of the accident on traffic overflows from the intersection to the upstream section of the west entrance, affecting the vehicle driving on the upstream section, and go to step (3).

[0119] (3) Calculate the speed ratio γ of the upstream section at a 2-minute time interval i ,i=1,2,...,40. If all γ i Greater than γ threshold , go to step (6); if there is γ i Less than γ threshold When , it is considered that the accident impact overflows from the road section to its upstream intersection, affecting the vehicle driving at the upstream intersection, and then go to step (2).

[0120] (4) Determine the road section level range affected by the accident as the accident section, take the accident location as the starting point of the queue congestion, and use traffic wave theory to estimate the specific scope of the accident impact.

[0121] (5) Determine the specific scope of the accident’s impact as all road sections and intersections involved in the above calculations.

[0122] (6) Determine the road section level range affected by the accident as all road sections and intersections involved in the above calculations, and use traffic wave theory to calculate the specific impact range of the boundary road sections, starting from μ xj Greater than μ threshold The calculation starts from the moment .

[0123] Based on the same inventive concept as the above embodiments, see Figure 9 , which shows the composition of a traffic accident impact range prediction device provided by an embodiment of the present invention, which may include: an acquisition module 10, a judgment module 20, and a processing module 30; wherein,

[0124] The acquisition module 10 is configured to acquire an average speed of vehicles on a road section when there is no accident, to obtain a first average speed; acquire an average speed of vehicles on the road section when an accident occurs, to obtain a second average speed; and acquire a speed ratio of the accident section based on the first average speed and the second average speed;

[0125] The judgment module 20 is configured to obtain an average speed of each direction passing through the intersection at an upstream adjacent intersection when the speed ratio satisfies a first threshold, and determine an intersection delay value for each direction of the upstream adjacent intersection based on the average speed passing through the intersection and the average speed of each direction passing through the intersection when there is no accident; and determine a target lane when any of the intersection delay values satisfies a second threshold;

[0126] The processing module 30 is configured to determine a boundary position of the accident impact based on the target lane.

[0127] Optionally, the processing module 30 is further configured to obtain a signal timing plan of the intersection corresponding to the target lane, and the density and flow of periodic traffic inflow and outflow of the target lane, so as to obtain a boundary position affected by the accident.

[0128] Optionally, the judgment module 20 is further used to determine the target lane based on the accident section when the speed ratio does not meet the first threshold; the processing module 30 is further used to determine the boundary position of the accident impact based on the target lane.

[0129] Optionally, the judgment module 20 is further used to determine the target lane corresponding to the upstream adjacent intersection when the delay value of any intersection does not meet the second threshold; the processing module 30 is further used to determine the boundary position of the accident impact based on the target lane.

[0130] Optionally, the judgment module 20 is further configured to, when any of the intersection delay values satisfies a second threshold, determine a speed ratio of an upstream adjacent intersection in a direction corresponding to the second threshold;

[0131] The process returns to the step of confirming whether the speed ratio satisfies the first threshold value until the target lane is determined.

[0132] In another embodiment, Figure 10 As shown, a computer device is also provided, comprising: at least one processor 210 and a memory 211 for storing a computer program that can be run on the processor 210; wherein, Figure 10 The processor 210 shown in the figure is not used to indicate that the number of processors is one, but is only used to indicate the positional relationship of the processor relative to other devices. In actual applications, the number of processors may be one or more; similarly, Figure 10The memory 211 shown in the figure has the same meaning, that is, it is only used to refer to the position relationship of the memory relative to other devices. In actual applications, the number of memories can be one or more.

[0133] The processor 210 is configured to execute the following steps when running the computer program:

[0134] Obtain the average speed of vehicles on the road section when there is no accident to obtain a first average speed; obtain the average speed of vehicles on the road section when an accident occurs to obtain a second average speed;

[0135] Obtaining a speed ratio of the accident section according to the first average speed and the second average speed;

[0136] When the speed ratio meets a first threshold, obtaining an average speed of each direction passing through the intersection at an upstream adjacent intersection, and determining an intersection delay value for each direction of the upstream adjacent intersection based on the average speed of passing through the intersection and the average speed of each direction passing through the intersection when there is no accident;

[0137] When any of the intersection delay values meets a second threshold, determining a target lane;

[0138] Based on the target lane, a boundary position of the accident impact is determined.

[0139] In an optional embodiment, the processor 210 is further configured to perform the following steps when running the computer program:

[0140] The signal timing plan of the intersection corresponding to the target lane, as well as the density and flow of periodic traffic inflow and outflow of the target lane are obtained to obtain the boundary position affected by the accident.

[0141] In an optional embodiment, the processor 210 is further configured to perform the following steps when running the computer program:

[0142] When the speed ratio does not meet a first threshold, determining a target lane based on the accident road section;

[0143] Based on the target lane, a boundary position of the accident impact is determined.

[0144] In an optional embodiment, the processor 210 is further configured to perform the following steps when running the computer program:

[0145] When the delay value of any of the intersections does not meet the second threshold, determining a target lane corresponding to an upstream adjacent intersection;

[0146] Based on the target lane, a boundary position of the accident impact is determined.

[0147] In an optional embodiment, the processor 210 is further configured to perform the following steps when running the computer program:

[0148] When the delay value of any of the intersections meets a second threshold, determining a speed ratio of an upstream adjacent intersection in a direction corresponding to the second threshold;

[0149] The process returns to the step of confirming whether the speed ratio satisfies the first threshold value until the target lane is determined.

[0150] The computer device may also include: at least one network interface 212. The various components in the sending end are coupled together via a bus system 213. It is understood that the bus system 213 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 213 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, Figure 10 Various buses are labeled as bus system 213.

[0151] The memory 211 may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a ferromagnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory may be a magnetic disk or a magnetic tape. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus random access memory (DRRAM).The memory 211 described in the embodiments of the present invention is intended to include, but is not limited to, these and any other suitable types of memory.

[0152] The memory 211 in the embodiment of the present invention is used to store various types of data to support the operation of the transmitting end. Examples of such data include any computer program used to operate on the transmitting end, such as an operating system and an application program. The operating system includes various system programs, such as a framework layer, a core library layer, and a driver layer, which are used to implement various basic services and handle hardware-based tasks. The application program may include various application programs for implementing various application services. Here, the program implementing the method of the embodiment of the present invention may be included in the application program.

[0153] This embodiment also provides a computer storage medium, for example, including a memory 211 storing a computer program. The computer program can be executed by the processor 210 in the sending end to complete the steps of the aforementioned method. The computer storage medium can be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disk, or CD-ROM; or it can be various devices including one or any combination of the above memories, such as a smartphone, tablet computer, laptop computer, etc. A computer storage medium, wherein the computer storage medium stores a computer program, when the computer program is executed by the processor, performs the following steps:

[0154] The processor 210 is configured to execute the following steps when running the computer program:

[0155] Obtain the average speed of vehicles on the road section when there is no accident to obtain a first average speed; obtain the average speed of vehicles on the road section when an accident occurs to obtain a second average speed;

[0156] Obtaining a speed ratio of the accident section according to the first average speed and the second average speed;

[0157] When the speed ratio meets a first threshold, obtaining an average speed of each direction passing through the intersection at an upstream adjacent intersection, and determining an intersection delay value for each direction of the upstream adjacent intersection based on the average speed of passing through the intersection and the average speed of each direction passing through the intersection when there is no accident;

[0158] When any of the intersection delay values meets a second threshold, determining a target lane;

[0159] Based on the target lane, a boundary position of the accident impact is determined.

[0160] In an optional embodiment, when the computer program is executed by a processor, the following steps are further performed:

[0161] The signal timing plan of the intersection corresponding to the target lane, as well as the density and flow of periodic traffic inflow and outflow of the target lane are obtained to obtain the boundary position affected by the accident.

[0162] In an optional embodiment, when the computer program is executed by a processor, the following steps are further performed:

[0163] When the speed ratio does not meet a first threshold, determining a target lane based on the accident road section;

[0164] Based on the target lane, a boundary position of the accident impact is determined.

[0165] In an optional embodiment, when the computer program is executed by a processor, the following steps are further performed:

[0166] When the delay value of any of the intersections does not meet the second threshold, determining a target lane corresponding to an upstream adjacent intersection;

[0167] Based on the target lane, a boundary position of the accident impact is determined.

[0168] In an optional embodiment, when the computer program is executed by a processor, the following steps are further performed:

[0169] When the delay value of any of the intersections meets a second threshold, determining a speed ratio of an upstream adjacent intersection in a direction corresponding to the second threshold;

[0170] The process returns to the step of confirming whether the speed ratio satisfies the first threshold value until the target lane is determined.

[0171] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0172] As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion of elements other than the listed elements and may also include additional elements not specifically listed.

[0173] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for predicting the impact range of a traffic accident, characterized in that: The method comprises: Obtain the average speed of vehicles on the road section when there is no accident to obtain a first average speed; obtain the average speed of vehicles on the road section when an accident occurs to obtain a second average speed; Obtaining a speed ratio of the accident section according to the first average speed and the second average speed; If the speed ratio does not meet the first threshold, it is considered that the maximum impact length of the accident on the road section does not exceed the accident section, and the section-level range affected by the accident is determined to be the accident section. The accident location is used as the starting point of the queue congestion, and the specific scope of the accident impact is estimated using traffic wave theory; When the speed ratio meets the first threshold, it is considered that the impact of the accident has spread from the road section to the upstream intersection, and the average speed of each direction through the intersection of the upstream adjacent intersection is obtained. The intersection delay value of each direction of the upstream adjacent intersection is determined based on the average speed through the intersection and the average speed of each direction through the intersection when there is no accident; when the intersection delay values in all directions do not meet the second threshold, the specific scope of the impact of the accident is determined to be the accident section and the upstream intersection; when the intersection delay value in a certain direction meets the second threshold, it is considered that the impact of the accident has spread from the accident section to the upstream section of the corresponding direction connected to the upstream intersection, and the speed ratio of the upstream section is calculated. Based on the speed ratio of the upstream section, it is determined whether the impact of the accident continues to spread from the upstream section, until all sections and intersections affected by the accident are finally determined.

2. The traffic accident impact range prediction method according to claim 1, characterized in that: The intersection delay values include: Where, μ is the delay value s at the intersection; L cross The signalized intersection range; is the average speed through the intersection range under accident conditions; It is the average speed of passing the intersection range under accident-free conditions.

3. A traffic accident impact range prediction device, characterized in that: include: a processor and a memory for storing a computer program capable of being executed on the processor, Wherein, when the processor is used to run the computer program, it implements the traffic accident impact range prediction method described in any one of claims 1 to 2.

4. A computer storage medium, characterized in that A computer program is stored, and when the computer program is executed by a processor, the method for predicting the impact range of a traffic accident as described in any one of claims 1 to 2 is implemented.

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