CN103632537B - A kind of urban road AADT method of estimation based on Floating Car - Google Patents

Abstract

The present invention relates to a kind of urban road AADT method of estimation based on Floating Car, compared with prior art solve the tradition low precision of AADT method of estimation, inefficient defect.The present invention comprises the following steps: utilize Floating Car gps data to calculate section bicycle sample speed；Extract road-section average travel speed；Calculate hour traffic flow；Estimate per day traffic flow；Estimate annual day traffic flow AADT.The present invention utilizes the Road average-speed that floating car technology obtains, and is calculated the intelligent accurately estimation realizing road AADT by a series of models.

Description

A kind of urban road AADT method of estimation based on Floating Car

Technical field

The present invention relates to traffic planninng technical field, a kind of urban road AADT based on Floating Car Method of estimation.

Background technology

AADT (the annual day traffic flow of road, annual average daily traffic) be traffic model and Management decision-making very important parameter, grinds in traffic programme, road design, traffic safety, transport need analysis, traffic control etc. Study carefully field and suffer from the effect of key.Owing to traditional AADT method uses manual counts, the representational moon in selecting 1 year Carrying out investigation records in artificial 24 hours in Fen in a certain week each day, record result is multiplied by week nonuniformity coefficient, moon heterogeneous system Count thus obtain AADT.This method takes time and effort, and precision is relatively low, due to week nonuniformity coefficient and the value of uneven factor of monthly consumption It is changeless, for the different grades of roads such as through street, trunk roads, secondary distributor road, branch road, does not carry out detailed district Point, therefore traditional AADT method precision is relatively low.

Floating car technology is to run vehicle dynamic positional information according to pavement of road to obtain a kind of skill of road situation Art, utilization can be with the displacement information of Real-time Collection vehicle with the Floating Car (taxi or bus) of GPS information, by time sequence The vehicle location coordinate of row mates with map, can obtain the speed data of floating vehicle.Floating car technology can will be adopted The data collected 1 year store in data base, and the cycle link speed information of utilization obtains cycle link flow information.From time angle Degree is analyzed and from the point of view of theoretical research angle, and floating car technology can become the technical foundation calculating road AADT, thus avoids passing The system low precision of AADT method, inefficient defect.But how to develop one to realize road, city based on floating car technology The method that road AADT estimates has become as urgent need and solves the technical problem that.

Summary of the invention

The invention aims to solve the low precision of tradition AADT method of estimation in prior art, inefficient lack Fall into, it is provided that a kind of urban road AADT method of estimation based on Floating Car solves the problems referred to above.

To achieve these goals, technical scheme is as follows:

A kind of urban road AADT method of estimation based on Floating Car, comprises the following steps:

Floating Car gps data is utilized to calculate section bicycle sample speed；

Extract road-section average travel speed；

Calculate hour traffic flow

Estimate per day traffic flow；

Estimate annual day traffic flow AADT.

The described Floating Car gps data calculating section bicycle sample speed that utilizes comprises the following steps:

By Floating Car gps data obtain before and after sample vehicle j is passed through adjacent 2 routing information Pi, i=1, 2 ..., M}, the section number that wherein M comprises in being the path that vehicle travels；

By path Δ d_jWith time difference Δ t_jObtain the Average Travel Speed in this section of path

If approach section number only one of which orKilometer/hour time, willIt is assigned to section P₁；Otherwise, by four kinds of traffic State principle combines the instantaneous velocity v of starting point₁Instantaneous velocity v with terminal₂, each section speed of approach is distinguished assignment.

The determination methods of four kinds of described traffic behavior principles is as follows:

Deceleration regime, meetsTime, initial section velocity amplitude is assigned toOther section velocity amplitude is total Travel time Δ t_jDeduct the travel time in initial section, then obtain speed by distance divided by this time；

Acceleration mode, meetsTime, terminate section velocity amplitude and be assigned toOther section velocity amplitude is total Travel time Δ t_jDeduct the travel time in initial section, then obtain speed by distance divided by this time；

First slowing down and accelerate afterwards, initial section velocity amplitude is assigned to v₁, terminate section velocity amplitude and be assigned to v₂, middle section velocity amplitude For total travel time Δ t_jDeduct the travel time in initial section, then obtain speed by distance divided by this time；

First accelerating to slow down afterwards, approach section velocity amplitude is assigned to

Described extraction road-section average travel speed computing formula is

$V_i=\left\{\begin{array}{ccc}\frac{l_i}{t_i}=\frac{l_i}{\left(\underset{j=1}{\overset{n}{\Σ}}\frac{l_i}{v_j}\right)/n}=\frac{n}{\underset{j=1}{\overset{n}{\Σ}}\frac{1}{v_j}},& if& n_i\≠0\\ {\stackrel{\‾}{V}}_i,& if& n_i=0\end{array}\right.$

Wherein, V_iFor segmental arc P_iAverage travel speed, l_iFor segmental arc P_iLength, n_iFor segmental arc P_iOn number of vehicles, t_iFor n Floating Car through P_iThe arithmetic mean of instantaneous value of time；V_jFor jth car segmental arc P in the paths_iOn travel speed； For segmental arc P_iThe historical average speeds of one week different time sections of historical accumulation；N is section P_iThe upper number of vehicles participating in calculating.

Described calculating hour traffic flow calculation procedure is as follows:

By cycle road-section average travel speed V_i, according to speed flowrate relational model, obtain the flow q in each cycle_j,

When unidirectional number of track-lines is 2,

When unidirectional number of track-lines is 3,

When unidirectional number of track-lines is 4,

Hour ratio K of 5 time periods is obtained from hour traffic congestion schedule of proportion_h；

Calculate hour traffic flow q_hi, its computing formula is

Wherein M_iFor determining corresponding correction factor, M for different periods_i=k_h/10。

Per day traffic flow Q of described estimation_dFormula be:

$Q_d=\underset{i=1}{\overset{24}{\Σ}}{q}_{hi}.$

The described formula estimating annual day traffic flow AADT is:

Wherein k is total natural law actual then.

Beneficial effect

A kind of based on Floating Car the urban road AADT method of estimation of the present invention, compared with prior art utilizes Floating Car The Road average-speed of technical limit spacing, calculates the intelligent accurately estimation realizing road AADT by a series of models.Meet Traffic programme, traffic design, the demand data of traffic administration, improve work efficiency.

Accompanying drawing explanation

Fig. 1 is the method flow diagram of the present invention.

Detailed description of the invention

By making the architectural feature to the present invention and effect of being reached have a better understanding and awareness, in order to preferably Embodiment and accompanying drawing coordinate detailed description, are described as follows:

The data gathering 1 year can be stored in data base by floating car technology, and the cycle link speed information of utilization obtains Cycle link flow information.The spatial averaging taking all floatings in section spot speed can obtain the real-time average speeds in section, will Section real-time speed in some cycles carries out arithmetic average can obtain the cycle average speed of road, then according to multi-period Dividing, weighted calculation obtains the day traffic flow of road, and then the day traffic flow of a year is carried out arithmetic average obtains road Annual day traffic flow.As it is shown in figure 1, a kind of urban road AADT estimation side based on Floating Car of the present invention Method, it is characterised in that comprise the following steps:

The first step, utilizes Floating Car gps data to calculate section bicycle sample speed.

Floating Car gps data is utilized to calculate bicycle sample mean travelling speed in a measurement period in section, first, logical Cross Floating Car gps data obtain before and after sample vehicle j is passed through adjacent 2 routing information Pi, i=1,2 ..., M}.Its Secondary, path Δ d can be passed through based on gps data_jWith time difference Δ t_jObtain the Average Travel Speed in this section of pathAgain, i.e. represent not across crossing when approach section number only one of which orKilometer/hour i.e. unimpeded shape During state, willIt is assigned to section P₁；Otherwise, by the instantaneous velocity v combining starting point₁Instantaneous velocity v with terminal₂, point four kinds of traffic shapes State speed assignment respectively in each section to approach.

When Floating Car is in deceleration regime, the most satisfiedTime, initial section velocity amplitude is assigned toOther Section velocity amplitude is total travel time Δ t_jDeduct the travel time in initial section, then obtained divided by this time by distance Speed, then speed is assigned to section P₁。

When Floating Car is in acceleration mode, meetTime, terminate section velocity amplitude and be assigned toOther road Section velocity amplitude is total travel time Δ t_jDeduct the travel time in initial section, then obtain speed by distance divided by this time Degree, then speed is assigned to section P₁。

Accelerating afterwards when Floating Car is in first to slow down, initial section velocity amplitude is assigned to v₁, terminate section velocity amplitude and be assigned to v₂In, Between section velocity amplitude be total travel time Δ t_jDeduct the travel time in initial section, then obtained divided by this time by distance To speed, then speed is assigned to section P₁。

First accelerating to slow down afterwards when Floating Car is in, approach section velocity amplitude is assigned toAgain willIt is assigned to section P₁。

Second step, extracts road-section average travel speed.

Extracting road-section average travel speed computing formula is

$V_i=\left\{\begin{array}{ccc}\frac{l_i}{t_i}=\frac{l_i}{\left(\underset{j=1}{\overset{n}{\Σ}}\frac{l_i}{v_j}\right)/n}=\frac{n}{\underset{j=1}{\overset{n}{\Σ}}\frac{1}{v_j}},& if& n_i\≠0\\ {\stackrel{\‾}{V}}_i,& if& n_i=0\end{array}\right.$

Wherein, V_iFor segmental arc P_iAverage travel speed, l_iFor segmental arc P_iLength, n_iFor segmental arc P_iOn number of vehicles, t_iFor n Floating Car through P_iThe arithmetic mean of instantaneous value of time；V_jFor jth car segmental arc P in the paths_iOn travel speed； For segmental arc P_iThe historical average speeds of one week different time sections of historical accumulation；N is section P_iThe upper number of vehicles participating in calculating. Here, n is worked as_iEqual to 0, when i.e. not having data cover on this section, we use the history of one week different time sections of historical accumulation Average speed supplements；Work as n_iWhen being not equal to 0, road-section average travel speed is then the harmonic average speed of multiple sample.

3rd step, calculates hour traffic flow.

Calculate hour traffic flow calculation procedure as follows:

First, by cycle road-section average travel speed V_i, according to speed flowrate relational model, obtain the stream in each cycle Amount q_j。

The domestic urban road unidirectional number of track-lines of standard-required major trunk roads can be 2,3 or 4, according to domestic system One urban road required standard, it is only necessary to when being 2,3 or 4 for unidirectional number of track-lines, carries out cycle q_jCalculating.According to city City's major trunk roads speed flowrate relational model can draw,

When unidirectional number of track-lines is 2,

When unidirectional number of track-lines is 3,

When unidirectional number of track-lines is 4,

Above formula selects the speed-density model that Holland Van Aerde proposes, then according to the relation of traffic three parameter Draw Speed-flow Relationship, and on the basis of this according to traffic flow free stream, saturated flow and obstruction stream mode traffic characteristic not With, its correlation model coefficient is demarcated by speed, data on flows in conjunction with the actual measurement of the city video detector of a year. The speed-density model formula that Holland Van Aerde proposes isWhen surveyed road is major trunk roads, It it is then the computing formula of unidirectional number of track-lines corresponding above.When surveyed road is through street, when unidirectional number of track-lines is 2,

$q=\frac{v}{0.006608926+\frac{0.026593058}{68-v}+0.000448705*v};$

When unidirectional number of track-lines is 3,

$q=\frac{v}{0.000376417+\frac{0.63275737}{83-v}+0.0002234635*v}.$

When surveyed road is secondary distributor road, when unidirectional number of track-lines is 1,

$q=\frac{v}{-0.015123457+\frac{1.10617284}{50-v}-0.000311016*v};$

When unidirectional number of track-lines is 2,

When unidirectional number of track-lines is 3,

$q=\frac{v}{-0.004571429+\frac{0.925714286}{80-v}+0.000542857*v}.$

Secondly, hour ratio K of 5 time periods is obtained from hour traffic congestion schedule of proportion_h。

Being illustrated according to " urban road traffic congestion assessment indicator system " (exposure draft), owing to travelling frequently, peak is caused Road traffic peak period sooner or later, the morning peak period is 7:00-9:00, the evening peak period is 17:00-19:00.Therefore basis " urban road traffic congestion assessment indicator system " exposure draft, traffic congestion index be in statistical interval city overall or The relative number of the overall congestion level of area road net, marks off 5 time periods, thus goes through according to conventional road for one day 24 hours History data and survey result make a hour traffic congestion schedule of proportion (table 1).

1 hour traffic congestion schedule of proportion of table

Parameter	t1	t2	t3	t4	t5
						Time	0-7	7-9	9-17	17-19	19-24
Toatl proportion	8	20	40	20	12
						Hour ratio Kh	1.14	10	5	10	2.4

Wherein toatl proportion is the traffic congestion index that historical data based on Floating Car magnanimity calculates, and forms annual 24 hours curves of traffic congestion index, then according to 5 time periods divided, the area of gauge index curve, each ratio Value is exactly the ratio of each interval time section area.Hour ratio K_hBe segment area ratio divided by segment hour Number.

Again, each cycle q is obtained_j, and then hour traffic flow q can be calculated by formula_hi.Calculate a hour friendship Through-current capacity q_hi, its computing formula is

Wherein M_iFor determining corresponding correction factor, M for different periods_i=k_h/10。

Tie up to peak, the flat peak period property of there are differences owing to speed flowrate closes, cause precision in different periods different, therefore Corresponding correction factor M is determined for different periods_i。

4th step, estimates per day traffic flow.

Estimate per day traffic flow Q_dFormula be:

$Q_d=\underset{i=1}{\overset{24}{\Σ}}{q}_{hi}.$

After according to multi-period division, weighted calculation obtains the per day traffic flow of road.

5th step, estimates annual day traffic flow AADT.

In the day traffic flow of road by the time, and then the day traffic flow of a year is carried out arithmetic average obtain the year of road Averagely day traffic flow, estimates that the formula of annual day traffic flow AADT is:

Wherein k is total natural law actual then.

AADT that is one year every day per day traffic flow arithmetic mean of instantaneous value, wherein k=365 or 366, actual value Determine according to actual total natural law then.Thus the gps data eventually through Floating Car estimates the traffic flow of annual day Amount AADT.

The ultimate principle of the present invention, principal character and advantages of the present invention have more than been shown and described.The technology of the industry The personnel simply present invention it should be appreciated that the present invention is not restricted to the described embodiments, described in above-described embodiment and description Principle, the present invention also has various changes and modifications without departing from the spirit and scope of the present invention, these change and Improvement both falls within the range of claimed invention.The protection domain of application claims by appending claims and Equivalent defines.

Claims (4)

1. a urban road AADT method of estimation based on Floating Car, it is characterised in that comprise the following steps:

1) utilize Floating Car gps data to calculate section bicycle sample speed, comprise the following steps:

11) by Floating Car gps data obtain before and after sample vehicle j is passed through adjacent 2 routing information Pi, i=1, 2 ..., M}, the section number that wherein M comprises in being the path that vehicle travels；

12) by path Δ d_jWith total travel time Δ t_jObtain the Average Travel Speed in this section of path

13) if approach section number only one of which orKilometer/hour time, willIt is assigned to section P₁；Otherwise, by four kinds of traffic shapes State principle combines the instantaneous velocity v of starting point₁Instantaneous velocity v with terminal₂, each section speed of approach is distinguished assignment；Described The determination methods of four kinds of traffic behavior principles as follows:

131) deceleration regime, meetsTime, initial section velocity amplitude is assigned toOther section velocity amplitude is total Travel time Δ t_jDeduct the travel time in initial section, then obtain speed by distance divided by this time；

132) acceleration mode, meetsTime, terminate section velocity amplitude and be assigned toOther section velocity amplitude is total Travel time Δ t_jDeduct the travel time in initial section, then obtain speed by distance divided by this time；

133) first slowing down and accelerate afterwards, initial section velocity amplitude is assigned to v₁, terminate section velocity amplitude and be assigned to v₂, middle section velocity amplitude For total travel time Δ t_jDeduct the travel time in initial section, then obtain speed by distance divided by this time；

134) first accelerating to slow down afterwards, approach section velocity amplitude is assigned to

2) road-section average travel speed is extracted；

3) calculating hour traffic flow, described calculating hour traffic flow calculation procedure is as follows:

31) by cycle road-section average travel speed V_i, according to speed flowrate relational model, obtain the flow q in each cycle_j,

When unidirectional number of track-lines is 2,

When unidirectional number of track-lines is 3,

When unidirectional number of track-lines is 4,

32) city entirety or the relative number of the overall congestion level of area road net in traffic congestion index is statistical interval, one day Within 24 hours, mark off 5 time periods, thus make a hour traffic congestion according to conventional road history data and survey result Schedule of proportion, obtains hour ratio k of 5 time periods from hour traffic congestion schedule of proportion_h；

33) hour traffic flow q is calculated_hi, its computing formula is

Wherein M_iFor determining corresponding correction factor for different periods,

4) per day traffic flow is estimated；

5) annual day traffic flow AADT is estimated.

A kind of urban road AADT method of estimation based on Floating Car the most according to claim 1, it is characterised in that described Extraction road-section average travel speed computing formula be

$V_i=\left\{\begin{array}{ccc}\frac{l_i}{t_i}=\frac{l_i}{\left(\underset{j=1}{\overset{n}{\Σ}}\frac{l_i}{v_j}\right)/n}=\frac{n}{\underset{j=1}{\overset{n}{\Σ}}\frac{1}{v_j}},& if& n_i\≠0\\ \stackrel{\‾}{V_i},& if& n_i=0\end{array}\right.$

Wherein, V_iFor segmental arc P_iAverage travel speed, l_iFor segmental arc P_iLength, n_iFor segmental arc P_iOn number of vehicles, t_iFor n Floating Car is through P_iThe arithmetic mean of instantaneous value of time；V_jFor jth car segmental arc P in the paths_iOn travel speed；For arc Section P_iThe historical average speeds of one week different time sections of historical accumulation；N is segmental arc P_iThe upper number of vehicles participating in calculating.

A kind of urban road AADT method of estimation based on Floating Car the most according to claim 1, it is characterised in that described Per day traffic flow Q of estimation_dFormula be:

$Q_d=\underset{i=1}{\overset{24}{\Σ}}{q}_{hi}.$

A kind of urban road AADT method of estimation based on Floating Car the most according to claim 1, it is characterised in that described Estimate annual day traffic flow AADT formula be:

Wherein k is total natural law actual then.