CN106157619A - Under hypersaturated state, road network is in fortune vehicle number computational methods - Google Patents

Abstract

The invention discloses road network under a kind of hypersaturated state and transport vehicle number computational methods.The method is for the road network of evening peak hypersaturated state morning, and for given road network state, integrated use traffic flow theory and mathematical statistics method, the road network being calculated under corresponding state is at fortune vehicle number.For achieving the above object, under the hypersaturated state that the present invention proposes, road network comprises the following steps in fortune vehicle number computational methods: gather road network static traffic data, including road section length, section number of track-lines；Gather road network dynamic traffic data, demarcate section free stream velocity, section critical density and section jam density；Calculate the vehicle rate in section；Calculate road network at fortune vehicle number.

Description

Under hypersaturated state, road network is in fortune vehicle number computational methods

Technical field

The present invention relates to road network under a kind of hypersaturated state and transport vehicle number computational methods, for the traffic pipe of city road network Reason and making policies support, belong to intelligent transportation field.

Background technology

Along with continuing to increase of vehicle guaranteeding organic quantity, urban traffic blocking is day by day serious, peak period morning and evening problem outstanding It highlights, and this brings challenge greatly to traffic administration.The most many cities take car limit to purchase, and restricted driving peak period etc. is arranged Execute and alleviate blocking up of peak period.But at present the making policies of restricting the number period and restricting the number quantity is lacked quantification foundation, example Can realize road network run under desired state as limited several numbers every day, peak period, how long limit can realize desired peak clipping Effect etc., and existing research do not has document (system) to realize calculating (monitoring) to road network vehicle number.

The traffic surveillance and control system such as road traffic of various places runs index system and Internet map service provider provides at present Road traffic state data all achieve monitoring and the description of the net state that satisfies the need of the net spee that satisfies the need, this carries out road network for us Evaluate and provide strong data supporting.

The most necessary road network that proposes on the basis of available data under hypersaturated state in fortune vehicle number computational methods, Utilize existing traffic speed data, provide the road network under different road network state at fortune vehicle number, it is achieved traffic behavior and road network The coordinated monitoring of vehicle number, provides scientific quantitative analysis foundation for scientific management decision-making.

Summary of the invention

It is an object of the invention to provide road network under a kind of hypersaturated state and transport vehicle number computational methods.The method for The early road network of evening peak hypersaturated state, for given road network state, integrated use traffic flow theory and mathematical statistics method, Be calculated to should road network under state at fortune vehicle number.For realizing above-mentioned target, under the hypersaturated state that the present invention proposes Road network includes in fortune vehicle number computational methods: gather road network static traffic data, gathers road network dynamic traffic data, calculates section Vehicle rate and calculate road network fortune vehicle number.

The basic step of the present invention is as follows:

S1: gather road network static traffic data, including road section length, section number of track-lines；

S2: gather road network dynamic traffic data, demarcates section free stream velocity, section critical density and section and blocks close Degree；

S3: calculate the vehicle rate in section；

S4: calculate road network at fortune vehicle number.

The process of step S1 includes:

S11: by road, road network is divided into different sections with crossing for node, and two-way road is based on two sections Calculate, measure length l in each section_iUnit km (km).

S12: carry out traffic study, gathers the number of track-lines n in each section_i。

The process of step S2 includes:

S21: road section traffic volume flow and speed in the acquisition units time, demarcate section free stream velocity v_fWith optimum density k_m

For section i, under certain Fixed Time Interval, gather this section speed of continuous one day and data on flows.

Speed data is sorted from small to large, obtains sequence v_i ¹, v_i ²,…v_i ^k, take the speed data of unilateral 5th percentile Free stream velocity v as this section_if, i.e.

P (V ＞ v_if)=0.05, V ∈ { v_i ¹, v_i ²,…v_i ^k} (1)

Data on flows is sorted from big to small, obtains sequence q_i ¹, q_i ²,…q_i ^k, take the flow number of first five percentile unilateral According to and the velocity amplitude of correspondence, then optimum density k of section i_miCan demarcate as follows:

$k_{mi}=\frac{\underset{\mathrm{\γ}=1}{\overset{0.05k}{\Σ}}{q_i}^{\mathrm{\γ}}}{n_i\·\underset{\mathrm{\γ}=1}{\overset{0.05k}{\Σ}}{v_i}^{\mathrm{\γ}}}---\left(2\right)$

Wherein: in traffic flow, k represents the traffic flow density in section；k_mRepresent the optimum density in section, i.e. link flow to reach To traffic flow density time maximum；k_jRepresent the jam density in section, i.e. traffic flow density during road traffic delay total blockage. Three's unit is veh/km.

S22: section jam density k_jDemarcation

For section i, distance L of the tail of the queue road stop line when peak period chooses vehicle queue and queuing vehicle number p, The then jam density k of section i_jiIt is demarcated as

$k_{ji}=\frac{p}{L}---\left(3\right)$

S24: gather the speed v of m-th period under hypersaturated state_i ^m

For the speed v of the m-th period of section i under hypersaturated state_i ^mIndex monitoring can be run flat by road grid traffic Platform obtains, it is possible to obtained by Floating Car gps data coupling.Hypersaturated state refer to section downstream intersection queuing vehicle without Method once discharges the traffic behavior needing secondary to queue up.

The process of step S3 includes:

For section i and the speed v of m-th period thereof_i ^m, its vehicle rate is calculated by below equation:

${\mathrm{\α}}_i^m=\frac{v_i^m}{v_{fi}\·k_{mi}}-\frac{v_i^m}{v_{fi}\·k_{ji}}---\left(4\right)$

The process of step S4 includes:

For the traffic behavior in each section in given road network and certain period road network, it is transporting vehicle number by below equation Calculate:

$N^m=\underset{i}{\Σ}\frac{n_i\·l_i}{{\mathrm{\α}}_i^m+1/k_{ji}}---\left(5\right)$

Owing to using above technical scheme, the present invention has the advantages that

1, combine the existing road network in a lot of city and run index platform data, it is achieved road network vehicle number under hypersaturated state Calculate and monitoring.

2, road net traffic state and road network are connected at fortune vehicle number, using the teaching of the invention it is possible to provide the road network vehicle of given state Number, the solution formulation for traffic administration with control provides decision support.

Accompanying drawing explanation

The overall flow figure of Fig. 1 the present invention program.

Fig. 2 road network schematic diagram.

Fig. 3 free stream velocity chooses schematic diagram.

Fig. 4 road network vehicle number result of calculation.

Detailed description of the invention

Below in conjunction with accompanying drawing 1, the invention will be further described

The basic step of the present invention is as follows:

S1: gather road network static traffic data, including road section length, section number of track-lines；

S2: gather road network dynamic traffic data, demarcates section free stream velocity, section critical density and section and blocks close Degree；

S3: calculate the vehicle rate in section；

S4: calculate road network at fortune vehicle number.

The process of step S1 includes:

S11: by road, road network is divided into different sections with crossing for node, and two-way road is based on two sections Calculate, measure length l in each section_iUnit km (km), such as Fig. 2.

S12: carry out traffic study, gathers the number of track-lines n in each section_i。

The process of step S2 includes:

S21: road section traffic volume flow and speed in the acquisition units time, demarcate section free stream velocity and optimum density

For section i, under certain Fixed Time Interval, gather this section speed of continuous one day and data on flows.

Speed data is sorted from small to large, obtains sequence v_i ¹, v_i ²,…v_i ^k, take the speed data of unilateral 5th percentile Free stream velocity v as this section_if, see Fig. 3, i.e.

P (V ＞ v_if)=0.05, V ∈ { v_i ¹, v_i ²,…v_i ^k} (1)

Data on flows is sorted from big to small, obtains sequence q_i ¹, q_i ²,…q_i ^k, take the flow number of first five percentile unilateral According to and the velocity amplitude of correspondence, then section optimum density k_miCan demarcate as follows:

$k_{mi}=\frac{\underset{\mathrm{\γ}=1}{\overset{0.05k}{\Σ}}{q_i}^{\mathrm{\γ}}}{n_i\·\underset{\mathrm{\γ}=1}{\overset{0.05k}{\Σ}}{v_i}^{\mathrm{\γ}}}---\left(2\right)$

S22: the demarcation of section jam density

For section i, distance L of the tail of the queue road stop line when peak period chooses vehicle queue and queuing vehicle number p, The then jam density k in this section_jiIt is demarcated as

$k_{ji}=\frac{p}{L}---\left(3\right)$

S24: gather the speed v of m-th period under hypersaturated state_i ^m

For the speed v of the m-th period of section i under hypersaturated state_i ^mIndex monitoring can be run flat by road grid traffic Platform obtains, it is possible to obtained by Floating Car gps data coupling.Hypersaturated state refer to section downstream intersection queuing vehicle without Method once discharges the traffic behavior needing secondary to queue up.

The process of step S3 includes:

For section i and the speed v of m-th period thereof_i ^m, its vehicle rate is calculated by below equation:

${\mathrm{\α}}_i^m=\frac{v_i^m}{v_{fi}\·k_{mi}}-\frac{v_i^m}{v_{fi}\·k_{ji}}---\left(4\right)$

The process of step S4 includes:

For the traffic behavior in each section in given road network and certain period road network, it is transporting vehicle number by below equation Calculate:

$N^m=\underset{i}{\Σ}\frac{n_i\·l_i}{{\mathrm{\α}}_i^m+1/k_{ji}}---\left(5\right)$

With certain urban road network data as example, road network under hypersaturated state is carried out by the application present invention at fortune vehicle number Calculating, the present invention is further illustrated.

Detailed process is as follows:

1, choose survey region, gather road network static traffic data；

Present case chooses certain city, down town secondary distributor road and ratings above road, is that node division amounts to according to crossing 2292 different sections of highways (two-way section is calculated by 2 different directions sections), are denoted as

l₁,l₂,l₃,…l₂₂₉₂

Corresponding section number of track-lines is denoted as respectively

n₁,n₂,n₃,…n₂₂₉₂

2, gather road network dynamic traffic data, demarcate section free stream velocity, section critical density, section jam density；

(1) gather road network dynamic traffic data, with 5min as time interval, obtain this section speed of continuous one day and stream Amount data, each section amounts to 288 datas on flows and 288 speed datas.

(2) section free stream velocity is demarcated: the speed data in each section is sorted the most from big to small, i-th section Sort as follows: v_i0 ¹,v_i0 ²,…v_i0 ²⁸⁸, take the 15th data (the 5th percentile) free stream velocity as the i-th section, i.e. v_if =v_i0 ¹⁵。

(3) each section optimum density is demarcated: the data on flows in each section is ordered as the most from big to small: q_i ¹, q_i ²,…q_i ²⁸⁸, take front 15 data (first five percentile evidence) and the speed v of correspondence thereof_i ¹,v_i ²,…v_i ¹⁵, calculate section i Optimum density be

$k_{mi}=\frac{\underset{\mathrm{\γ}=1}{\overset{15}{\Σ}}{q_i}^{\mathrm{\γ}}}{n_i\·\underset{\mathrm{\γ}=1}{\overset{15}{\Σ}}{v_i}^{\mathrm{\γ}}}$

(3) section jam density is demarcated: distance L of the tail of the queue road stop line when peak period chooses vehicle queue and row Team vehicle number p, then the jam density of section i is

$k_{ji}=\frac{p}{L}$

According to investigation, the jam density in each section at 120veh/km, for simple and Convenient Calculation, takes k substantially_j=120veh/km.

3, the vehicle rate in section under hypersaturated state is calculated；

(1) section speed under hypersaturated state is gathered: obtained under hypersaturated state by road grid traffic operation monitoring platform Speed.By morning peak 8:00～as a example by the 8:05 time period (m=97), the speed v of the 97th period of section i_i ⁹⁷。

(2) the vehicle rate of calculating time period 97 section i:

${\mathrm{\α}}_i^{97}=\frac{v_i^{97}}{v_{fi}\·k_{mi}}-\frac{v_i^{97}}{v_{fi}\·k_{ji}}$

4, zoning road network is at fortune vehicle number:

Certain city, down town secondary distributor road and ratings above road morning peak 8:00～8:05 time period at fortune vehicle number be:

In like manner, can calculate morning peak period Regional Road Network and transport vehicle number, result is as shown in Figure 4.

The above-mentioned description to formula and example is only general case explanation, is the technology people for the ease of this technical field Member is understood that and applies the present invention.Those of ordinary skill in the art obviously can easily formula be modified use and not Must carry out creative work, the most every according to the amendment without departing from scope made in the scope of the claims of the present invention with change Entering all should be within protection scope of the present invention.

Claims (1)

1. under hypersaturated state, road network is transporting vehicle number computational methods, it is characterised in that the method comprises the following steps:

S1: gather road network static traffic data, including road section length, section number of track-lines, specifically:

S11: by road, road network is divided into different sections with crossing for node, and two-way road is calculated by two sections, surveys Measure length l in each section_i,

S12: carry out traffic study, gathers the number of track-lines n in each section_i；

S2: gather road network dynamic traffic data, demarcates section free stream velocity, section critical density and section jam density, tool Body is:

S21: road section traffic volume flow and speed in the acquisition units time, demarcate section free stream velocity v_fWith optimum density k_m

For section i, under certain Fixed Time Interval, gather this section speed of continuous one day and data on flows；

Speed data is sorted from small to large, obtains sequence v_i ¹, v_i ²,…v_i ^k, take the speed data conduct of unilateral 5th percentile The free stream velocity v in this section_if, i.e.

P (V ＞ v_if)=0.05, V ∈ { v_i ¹, v_i ²,…v_i ^k}

Data on flows is sorted from big to small, obtains sequence q_i ¹, q_i ²,…q_i ^k, take first five percentile unilateral data on flows and The velocity amplitude of its correspondence, then optimum density k of section i_miDemarcate as follows:

$k_{mi}=\frac{\underset{\mathrm{\γ}=1}{\overset{0.05k}{\Σ}}{q_i}^{\mathrm{\γ}}}{n_i\·\underset{\mathrm{\γ}=1}{\overset{0.05k}{\Σ}}{v_i}^{\mathrm{\γ}}}$

Wherein: in traffic flow, k represents the traffic flow density in section；k_mRepresent the optimum density in section, i.e. link flow and reach maximum Time traffic flow density；k_jRepresent the jam density in section, i.e. traffic flow density during road traffic delay total blockage；Three is single Position is veh/km；

S22: section jam density k_jDemarcation

For section i, distance L of the tail of the queue road stop line when peak period chooses vehicle queue and queuing vehicle number p, then road The jam density k of section i_jiIt is demarcated as

$k_{ji}=\frac{p}{L}$

S24: gather the speed v of m-th period under hypersaturated state_i ^m

For the speed v of the m-th period of section i under hypersaturated state_i ^mIndex monitor supervision platform can be run by road grid traffic to obtain Take, it is possible to obtained by Floating Car gps data coupling；Hypersaturated state refers to section downstream intersection queuing vehicle cannot one Secondary discharge the traffic behavior needing secondary to queue up；

S3: calculate the vehicle rate in section, specifically:

For section i and the speed v of m-th period thereof_i ^m, its vehicle rate is calculated by below equation:

${\mathrm{\α}}_i^m=\frac{v_i^m}{v_{fi}\·k_{mi}}-\frac{v_i^m}{v_{fi}\·k_{ji}}$

S4: calculate road network and transporting vehicle number, specifically:

For the traffic behavior in each section in given road network and certain period road network, it is calculated by below equation at fortune vehicle number Draw:

$N^m=\underset{i}{\Σ}\frac{n_i\·l_i}{{\mathrm{\α}}_i^m+1/k_{ji}}.$