CN104361460A - Road service level evaluation method adopting fuzzy synthetic evaluation method - Google Patents

Abstract

The invention provides a road service level evaluation method adopting a fuzzy synthetic evaluation method. According to the method, the traffic running state of a road segment is evaluated according to five service levels. For city expressways and main stems, an evaluation index is established according to two parameters including road segment average speed and traffic flow density, and then a fuzzy synthetic judgment is made; for city secondary main roads and branches, the traffic flow density is directly adopted for evaluation. The method has the advantages that a synthetic road network evaluation method is put forward, the running state of a road network can be reflected from multiple angles, basic road types can be covered, and evaluation results are displayed visually and concisely in a quantified mode.

Description

Adopt the Assessment of Serviceability of Roads evaluation method of fuzzy synthetic appraisement method

Technical field

The present invention relates to a kind of Assessment of Serviceability of Roads evaluation method adopting fuzzy synthetic appraisement method, for reasonably evaluating Assessment of Serviceability of Roads.

Background technology

Assessment of Serviceability of Roads is the index weighing the service quality that traffic flow service condition and driver and passenger experience, and the index determination service level such as to be usually interrupted, comfortable and convenient according to the volume of traffic, speed, running time, driving degree of freedom, traffic.Service level reflect road under certain transportation condition the quality level of operation service is provided.Assessment of Serviceability of Roads reasonably being evaluated, contributing to providing scientific basis for understanding road.In the sixties in 20th century, the U.S. has tentatively established road service quality index system, is A to F six grades by level of service division.The research of China to the traffic capacity is started late, careful not to the assurance of traffic flow Changing Pattern, only Highway Service Level is divided into level Four, and service level evaluation standard does not contain whole road types.Owing to there is no unified standard to the evaluation of urban road service quality, therefore, a kind of science, the objective and Assessment of Serviceability of Roads evaluation method of quantification is necessary to set up.

According to the regulation of the Ministry of Construction " urban road design criterion " (CJJ37-90), urban road can be divided into city expressway, major urban arterial highway, city subsidiary road and Urban Branch Road four class, and its respective feature is as follows:

(1) city expressway: a large amount of in city, long distance, rapid transit service are mainly provided; When crossing with highway, through street, major trunk roads, generally adopt grade separation form, and only prospective vehicle travels, forbids that pedestrian and non motorized vehicle enters, and eliminates horizontal interference, ensure that the continuity of traffic flow; The import and export of through street adopt and all control or part control, the place turnover that vehicle can only specified; Its traffic stream characteristics and highway similar; General connection be some vital area in city, the magnitude of traffic flow is usually higher, and particularly the magnitude of traffic flow of peak period generally can close to the traffic capacity of road; Have the higher speed of a motor vehicle and the larger traffic capacity, design rate is 60-80km/h;

(2) major urban arterial highway: be the skeleton in urban road network, it connects each major divisions, city, station, harbour etc., and based on communication function, jointly sharing main visitor, the lorry stream in city with through street, is the main artey of communications of urban inner; Major trunk roads level-crossing spacing is advisable with 800-1200m, along both side should not arrange attract major vehicular movement, the stream of people public building sell mouth; Major trunk roads assume responsibility for main visitor, the lorry stream in city, and the magnitude of traffic flow is very large; Design rate is 30-60km/h;

(3) city subsidiary road: be the complementary arterial highway connecting major trunk roads, coordinates major trunk roads composition urban main road network; Be wagon flow in city, stream of people's main traffic collector distributor road, be provided with a large amount of public transport line, connect city each several part and collecting and distributing traffic, also have service function concurrently; A fairly large number of general traffic route in city during secondary distributor road, allows both sides to arrange and attracts the public building of the stream of people as shop, public place of entertainment etc., and should establish parking lot; Based on mixed traffic, the volume of traffic is larger; The interference that Vehicle flow is subject to non-vehicle flow and pedestrian stream is comparatively large, and travel speed is slow; And car type is complicated, various car speed differs greatly, and design rate is 20-50km/h;

(4) Urban Branch Road: the connecting line being subsidiary road and block road, should have public transport line to travel, and have shop along the street, solves some areas traffic, based on service function, along the line based on residential architecture; Be wagon flow in city, stream of people's main traffic collector distributor road, public transport line is closeer; Based on mixed traffic, the interference that Vehicle flow is subject to non-vehicle flow and pedestrian stream is comparatively large, and travel speed is slow, and car type is complicated, and various car speed differs greatly, and design rate is 20-40km/h.

Summary of the invention

Due to the singularity of existing problem and traffic problems, the present invention adopts fuzzy synthetic appraisement method to evaluate the Assessment of Serviceability of Roads in section, divides 5 class service levels to evaluate the traffic circulation state in section.

The method is specially: for city expressway and major trunk roads, takes Road average-speed and traffic flow density two parameters to carry out the foundation of evaluation index; Fuzzy comprehensive evoluation carries out as follows:

(1) set of factors U is set up: set of factors is the set that the factor composition of object is passed judgment in impact, i.e. U={u ₁, u ₂, u ₃, wherein u ₁, u ₂, u ₃represent that maximum queue length and the average per car of the saturation degree of crossing, each entrance driveway in crossing are incured loss through delay respectively;

(2) evaluation collection V is set up: evaluating collection is the set of estimator to the various possible judged result passed judgment on done by object, i.e. V={v ₁, v ₂, v ₃, v ₄, v ₅, wherein v ₁represent the unimpeded state in crossing, v ₂represent slight congestion state, v ₃represent congestion state, v ₄represent more crowded, v ₅represent seriously crowded;

(3) weight sets is set up: in order to characterize the significance level of each factor, corresponding weight should be given to each factor, forming weight sets W by each weight, being namely expressed as weight vector W={w ₁, w ₂, w ₃, each weight is answered normalization and is met nonnegativity condition, i.e. w ₁+ w ₂+ w ₃=1;

(4) single factor test fuzzy evaluation: single factor is evaluated from set of factors U, determines to pass judgment on object to evaluating the degree of membership concentrating each element; If pass judgment on object by when i-th factor is passed judgment in set of factors, a jth element v is concentrated to judge _ijdegree of membership be r _ij, then the available fuzzy set of result passed judgment on by i-th factor is expressed as:

$R_i=\frac{r_{i1}}{v_1}+\frac{r_{i2}}{v_2}+\frac{r_{i3}}{v_3}+\frac{r_{i4}}{v_4}+\frac{r_{i5}}{v_5}$

R is called single factor evaluation collection, simply can be expressed as R _i=(r _i1, r _i2, r _i3, r _i4, r _i5), the judge collection composition monofactorial Judgement Matrix by n factor:

$R=\left[\begin{array}{c}{R}_1\\ R_2\\ R_3\end{array}\right]=\left[\begin{array}{ccccc}{r}_{11}& r_{12}& r_{13}& r_{14}& r_{15}\\ r_{21}& r_{22}& r_{23}& r_{24}& r_{25}\\ r_{31}& r_{32}& r_{33}& r_{34}& r_{35}\end{array}\right]$

(5) fuzzy overall evaluation: when weight sets and singular index judgment matrix are all for determining known, carries out comprehensive evaluation by doing blurring mapping,

In formula, B is called fuzzy overall evaluation collection, and " ο " represents a kind of fuzzy composition computing, and select M (ο ,+) model, this Model Calculating Method is

$b_j=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{w}_i{r}_{\mathrm{ij}},j=\mathrm{1,2}...m$

B in formula _jbe called fuzzy overall evaluation collection, be called for short evaluation index, during for considering the affecting of all factors, evaluation object concentrates the degree of membership of i-th element to evaluating;

For city subsidiary road and branch road, then traffic flow density is directly adopted to evaluate.

Wherein, step (3) described weight sets adopts gray theory method, analytical hierarchy process and the significance level of expert method to factor each in set of factors to carry out analytical calculation, obtains weight matrix.

The present invention adopts trapezoidal membership function to set up membership function to evaluation index; Membership function is set up according to following evaluation criterion:

City expressway evaluation criterion one:

The road of design speed per hour 60km/h, traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 20 is slightly crowded,

Traffic flow density 25 ~ 35 is crowded,

Traffic flow density 45 ~ 60 is more crowded,

Traffic flow density >75 is seriously crowded;

The road of design speed per hour 70km/h and 80km/h, traffic flow density evaluation criterion is the same;

City expressway evaluation criterion two:

The highway of design speed per hour 60km/h, average velocity >55 is unimpeded,

Average velocity 50 ~ 40 is slightly crowded,

Average velocity 35 ~ 25 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <10 is seriously crowded;

The highway of design speed per hour 70km/h, average velocity >64 is unimpeded,

Average velocity 60 ~ 50 is slightly crowded,

Average velocity 40 ~ 30 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <10 is seriously crowded;

The highway of design speed per hour 80km/h, average velocity >72 is unimpeded,

Average velocity 65 ~ 55 is slightly crowded,

Average velocity 40 ~ 30 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <10 is seriously crowded;

Major urban arterial highway evaluation criterion one:

The road of design speed per hour 40km/h, traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 25 is slightly crowded,

Traffic flow density 35 ~ 45 is crowded,

Traffic flow density 55 ~ 65 is more crowded,

Traffic flow density >70 is seriously crowded;

The road of design speed per hour 50km/h and 60km/h, traffic flow density evaluation criterion is the same;

Major urban arterial highway evaluation criterion two:

The highway of design speed per hour 40km/h, average velocity >32 is unimpeded,

Average velocity 30 ~ 25 is slightly crowded,

Average velocity 20 ~ 15 is crowded,

Average velocity 10 ~ 5 is more crowded,

Average velocity <5 is seriously crowded;

The highway of design speed per hour 50km/h, average velocity >40 is unimpeded,

Average velocity 35 ~ 30 is slightly crowded,

Average velocity 25 ~ 15 is crowded,

Average velocity 10 ~ 5 is more crowded,

Average velocity <5 is seriously crowded;

The highway of design speed per hour 60km/h, average velocity >50 is unimpeded,

Average velocity 45 ~ 40 is slightly crowded,

Average velocity 35 ~ 25 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <5 is seriously crowded;

City subsidiary road evaluation criterion:

Traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 25 is slightly crowded,

Traffic flow density 30 ~ 40 is crowded,

Traffic flow density 50 ~ 60 is more crowded,

Traffic flow density >70 is seriously crowded;

Urban Branch Road evaluation criterion:

Traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 20 is slightly crowded,

Traffic flow density 25 ~ 35 is crowded,

Traffic flow density 40 ~ 55 is more crowded,

Traffic flow density >60 is seriously crowded;

Wherein, traffic flow density unit a: km ^-1track ^-1, average velocity unit: kmh ^-1;

Membership function is as follows:

${{\mathrm{\&mu;}}_i}^0\left(u\right)=\left\{\begin{array}{cc}1& u\&le;u_{\mathrm{vs}}\\ \frac{u_s-u}{u_s-u_{\mathrm{vs}}}& u_{\mathrm{vs}}<u\&le;u_{\mathrm{sl}}\\ 0& u_{\mathrm{sl}}<u\end{array}\right.$

${{\mathrm{\&mu;}}_i}^1\left(x\right)=\left\{\begin{array}{cc}0& u\&le;u_{\mathrm{vs}}\\ \frac{u-u_{\mathrm{vs}}}{u_{\mathrm{sl}}-u_{\mathrm{vs}}}& u_{\mathrm{vs}}<u\&le;u_{\mathrm{sl}}\\ 1& u_{\mathrm{sl}}<u\&le;u_{\mathrm{sr}}\\ \frac{u_{\mathrm{ml}}-u}{u_{\mathrm{sr}}-u_{\mathrm{ml}}}& u_{\mathrm{sr}}<u\&le;u_{\mathrm{ml}}\\ 0& x>u_{\mathrm{ml}}\end{array}\right.$

${{\mathrm{\&mu;}}_i}^2\left(x\right)=\left\{\begin{array}{cc}0& u\&le;u_{\mathrm{sr}}\\ \frac{u-u_{\mathrm{sr}}}{u_{\mathrm{ml}}-u_{\mathrm{sr}}}& u_{\mathrm{sr}}<u\&le;u_{\mathrm{ml}}\\ 1& u_{\mathrm{ml}}<u\&le;u_{\mathrm{mr}}\\ \frac{u_{\mathrm{ll}}-u}{u_{\mathrm{mr}}-u_{\mathrm{ll}}}& u_{\mathrm{mr}}<u\&le;u_{\mathrm{ll}}\\ 0& x>u_{\mathrm{ll}}\end{array}\right.$

${{\mathrm{\&mu;}}_i}^3\left(x\right)=\left\{\begin{array}{cc}0& u\&le;u_{\mathrm{mr}}\\ \frac{u-u_{\mathrm{mr}}}{u_{\mathrm{ll}}-u_{\mathrm{lr}}}& u_{\mathrm{mr}}<u\&le;u_{\mathrm{ll}}\\ 1& u_{\mathrm{ll}}<u\&le;u_{\mathrm{lr}}\\ \frac{u_{\mathrm{vll}}-u}{u_{\mathrm{lr}}-u_{\mathrm{vll}}}& u_{\mathrm{lr}}<u\&le;u_{\mathrm{vll}}\\ 0& x>u_{\mathrm{vll}}\end{array}\right.$

${{\mathrm{\&mu;}}_i}^4\left(u\right)=\left\{\begin{array}{cc}1& u\&le;u_{\mathrm{vll}}\\ \frac{u-u_{\mathrm{vll}}}{u_s-u_{\mathrm{vs}}}& u_{\mathrm{vll}}<u\&le;u_{\mathrm{sl}}\\ 0& u_{\mathrm{vlr}}<u\end{array}\right.$

Wherein, μ _i ⁰, μ _i ¹, μ _i ², μ _i ³, μ _i ⁴what represent is unimpeded, slightly crowded, crowded, more crowded, seriously crowded degree of membership, u _vsrepresent unimpeded critical value, u _slrepresent slightly crowded critical lvalue, u _srslightly crowded critical r value, u _mlrepresent crowded critical lvalue, u _mrrepresent crowded critical r value, u _llrepresent more crowded critical lvalue, u _lrrepresent more crowded critical r value, u _vllrepresent seriously crowded critical lvalue, u _vlrrepresent seriously crowded critical r value, u represents the traffic flow density or average velocity numerical value that collect.

Advantage of the present invention is: the method proposing a comprehensive road network evaluation, from the running status of multiple angle reflection road network, can contain basic road type, and evaluation result be adopted directly perceived, succinct the displaying of mode quantized.

Accompanying drawing explanation

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

Fig. 2 is the section geometric properties schematic diagram of the embodiment of the present invention.

Embodiment

Traditional road network state evaluation mode mainly adopts single index, is not enough to tackle complicated traffic; Evaluation object only has major urban arterial highway, cannot evaluate other types road; To the evaluation criterion that the running status of whole road network does not quantize.The present invention adopts fuzzy synthetic appraisement method to evaluate the traffic behavior in section, 5 class service levels are divided to evaluate the traffic circulation state in section, the selection of evaluation index should reflect the traffic of change, easily to obtain again and accuracy rate is high, therefore a susceptibility should be selected high, can reflect that the parameter of road section traffic volume state is to reflect road traffic state intuitively, average overall travel speed can meet the state reflection to road network change to a certain extent, but only utilizes average velocity index not comprehensive.The first, because the classification of the classification of road of China to different road has different speed restrictions, therefore adopt merely a speed index can not comprehensively reflect traffic overall picture; Second, speed can from the ruuning situation in the angle reflection section of time, but but cannot directly reflect that situation is occupied in space, and think in American Highway traffic capacity handbook, when vehicle flowrate is lower than 1300/hour time, the reflection that speed changes the volume of traffic is also insensitive, therefore, when weighing road section traffic volume operation conditions, we select Road average-speed and traffic flow density two parameters as the parameter weighing section operation conditions.

For city expressway and major trunk roads, its major function has been longer-distance trip is master.And secondary distributor road and branch road fundamental purpose solve some areas traffic, based on collecting and distributing traffic and service function.

Therefore for different stage urban road we adopt different evaluation methods, as shown in Figure 1, for city expressway and major trunk roads, take Road average-speed and traffic flow density two parameters to carry out the foundation of evaluation index.

Fuzzy comprehensive evoluation carries out as follows:

(1) set of factors U is set up: set of factors is the set that the factor composition of object is passed judgment in impact, usually represents with U, i.e. U={u ₁, u ₂, u ₃, u _irepresenting that the factor of object is passed judgment in impact, is exactly the saturation degree of crossing, the maximum queue length of each entrance driveway in crossing and on average per car delay specifically;

(2) evaluation collection V is set up: evaluating collection is the set of estimator to the various possible judged result passed judgment on done by object, represents, i.e. V={v with V ₁, v ₂, v ₃, v ₄, v ₅, wherein v ₁represent the unimpeded state v in crossing ₂represent slight congestion state, v ₃represent congestion state, v ₄represent more crowded, v ₅represent seriously crowded;

(3) set up weight sets: in all " factor ", the emphasis of people is different, stresses the different and weighting of degree according to people to each factor, just can provide suitable comprehensive evaluation, generally speaking, in evaluation factors, the significance level of each factor of evaluation is different.In order to characterize the significance level of each factor, corresponding weight should be given to each factor, forming weight sets W by each weight, being namely expressed as weight vector W={w ₁, w ₂, w ₃, usual each weight is answered normalization and meets nonnegativity condition, i.e. w ₁+ w ₂+ w ₃=1.Usual employing gray theory method, analytical hierarchy process and the significance level of expert method to factor each in set of factors carry out analytical calculation, obtain weight matrix;

(4) single factor test fuzzy evaluation.Single factor test fuzzy evaluation be exactly from set of factors U single factor evaluate, determine that passing judgment on object concentrates the degree of membership of each element to evaluating.If pass judgment on object by when i-th factor is passed judgment in set of factors, the degree of membership of a jth element is concentrated to be that the available fuzzy set of result then passed judgment on by i-th factor is expressed as to passing judgment on:

$R_i=\frac{r_{i1}}{v_1}+\frac{r_{i2}}{v_2}+\frac{r_{i3}}{v_3}+\frac{r_{i4}}{v_4}+\frac{r_{i5}}{v_5}$

R is called single factor evaluation collection, simply can be expressed as R _i=(r _i1, r _i2, r _i3, r _i4, r _i5), the judge collection composition monofactorial Judgement Matrix by n factor:

$R=\left[\begin{array}{c}{R}_1\\ R_2\\ R_3\end{array}\right]=\left[\begin{array}{ccccc}{r}_{11}& r_{12}& r_{13}& r_{14}& r_{15}\\ r_{21}& r_{22}& r_{23}& r_{24}& r_{25}\\ r_{31}& r_{32}& r_{33}& r_{34}& r_{35}\end{array}\right]$

(5) fuzzy overall evaluation.When weight sets and singular index judgment matrix are all for determining known, comprehensive evaluation can be carried out by doing blurring mapping.

In formula, B is called fuzzy overall evaluation collection, and " ο " represents certain fuzzy composition computing, selects M (ο, +) model, this model not only considers the impact of all factors, and remains the full detail of single gene judgement, and model effect in engineering judgment is good.This Model Calculating Method is

$b_j=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{w}_i{r}_{\mathrm{ij}},j=\mathrm{1,2}...m$

B in formula _jbe called fuzzy overall evaluation collection, be called for short evaluation index.During for considering the affecting of all factors, evaluation object concentrates the degree of membership of i-th element to evaluating.

Below in conjunction with drawings and Examples, the present invention will be further described.

One, the foundation of the membership function of factor of evaluation.

When carrying out fuzzy evaluation, determine that the size of the degree of membership of each factor each evaluation rank corresponding is the key that can whole judge be carried out, therefore, the determination of membership function (Membership Function) plays vital effect.For the method determined, in dissimilar judgment criteria, there is diverse ways at present.As long as can same fuzzy concept be reflected, just can solving practical problems in actual applications.

Here in conjunction with the corresponding relation of service level and each factor, formulated following evaluation criterion, and adopted trapezoidal membership function to set up membership function to evaluation index.

On the basis of highway in China traffic capacity handbook, provide following evaluation criterion:

Table 1 city expressway evaluation criterion

Table 2 major urban arterial highway evaluation criterion

For through street and major trunk roads, set up Fuzzy Evaluation System, set up appraisement system from the angle of road running status and Operating ettectiveness.Select major urban arterial highway speed per hour 60km/h mono-example to set up the membership function of fuzzy evaluation, other all can set up membership function according to the method for building up of trapezoidal membership function.

${{\mathrm{\&mu;}}_1}^0\left(x\right)=\left\{\begin{array}{cc}1& x\&le;10\\ -\frac{1}{5}x+3& 10<x\&le;15\\ 0& 15<x\end{array}\right.$

${{\mathrm{\&mu;}}_1}^1\left(x\right)=\left\{\begin{array}{cc}0& x\&le;10\\ \frac{1}{5}x-2& 10<x\&le;15\\ 1& 15<x\&le;25\\ -\frac{1}{10}x+\frac{7}{2}& 25<x\&le;35\\ 0& x>35\end{array}\right.$

${{\mathrm{\&mu;}}_1}^2\left(x\right)=\left\{\begin{array}{cc}0& x\&le;25\\ \frac{1}{10}x-\frac{5}{2}& 25<x\&le;35\\ 1& 35<x\&le;45\\ -\frac{1}{10}x+\frac{11}{2}& 45<x\&le;55\\ 0& x>55\end{array}\right.$

${{\mathrm{\&mu;}}_1}^3\left(x\right)=\left\{\begin{array}{cc}0& x\&le;45\\ \frac{1}{10}x-\frac{9}{2}& 45<x\&le;55\\ 1& 55<x\&le;65\\ -\frac{1}{5}x+14& 65<x\&le;70\\ 0& x>70\end{array}\right.$

${{\mathrm{\&mu;}}_1}^4\left(x\right)=1\left\{\begin{array}{cc}0& x\&le;65\\ \frac{1}{5}x-13& 65<x\&le;70\\ 1& x>70\end{array}\right.$

For city subsidiary road and branch road, due to the singularity of its function and considering when designing, usually its design speed per hour all belongs to medium scope on the low side, in addition, major function due to subsidiary road and branch road is the collecting and distributing and supporting of traffic, therefore, mainly adopts traffic flow density to weigh to its evaluation, utilize the test of simulation software, obtain following classification of assessment standard:

Table 3 city subsidiary road and branch road evaluation criterion

The method for building up of its membership function and process and major trunk roads similar, does not repeat them here.

Two, based on the block status evaluation test of VISSIM.

(1) foundation of road network is simulated

This section selects traffic simulation software VISSIM 6.30 to carry out simulating, verifying to evaluation method above.VISSIM traffic simulation software be one discrete, random, minimum time unit can be the Microscopic Traffic Simulation Mathematic Model of time step with 0.1s.Simulation test selects the part in Wuxi City Ling Hu main road, this part by seeing crossing ,-Ling Hu main road, hill path 1, crossing ,-Ling Hu main road, crossing 2, Wu Doulu, scape openings for the able and the worthy-Ling Hu main road 3, crossing ,-Ling Hu main road, scientific research North Road 4, the section of this four somes composition.Ling Hu main road is major urban arterial highway, and design speed per hour is 60km/h, and the magnitude of traffic flow inputted in emulation is the data of actual acquisition, and acquisition time is on February 21st, 2014, and the period of collection is 10:00-10:30 in the morning.

Road section selected geometrical feature as shown in Figure 2.Road section length between each crossing is as shown in table 4.

The each road section length parameter of table 4

Section	Length (m)	Section	Length (m)
				L 12	338	L 34	405
L 23	307

(2) section evaluation of running status

Emulation duration is set to 2000 seconds, and simulation accuracy is 1:1, and simulation velocity is 1:10, and the time interval is set to 60s; After bringing into operation, Output rusults file.We take intermediate period comparatively stable in emulation; Analyze during this period of time for the 1200s-1800s of emulation.Roughly can find out that from analogous diagram the traffic in most of section is all in unimpeded state.Here the average travel speed that finishing analysis obtains each section is carried out to the result of the 1200s-1800 period exported, as shown in table 5.

The section parameter of table 5 1200s-1800s time

Utilize the method establishment evaluation model of fuzzy evaluation, with section by L ₁₂for example, bring its density and speed parameter into major trunk roads, in the membership function of speed per hour 60km, obtain single factor evaluation collection:

$R=\left[\begin{array}{c}{R}_1\\ R_2\end{array}\right]=\left[\begin{array}{ccccc}{{\mathrm{\&mu;}}_1}^0\left(x_1\right)& {{\mathrm{\&mu;}}_1}^1\left(x_1\right)& {{\mathrm{\&mu;}}_1}^2\left(x_1\right)& {{\mathrm{\&mu;}}_1}^3\left(x_1\right)& {{\mathrm{\&mu;}}_1}^4\left(x_1\right)\\ {{\mathrm{\&mu;}}_2}^0\left(x_2\right)& {{\mathrm{\&mu;}}_2}^1\left(x_2\right)& {{\mathrm{\&mu;}}_2}^2\left(x_2\right)& {{\mathrm{\&mu;}}_2}^3\left(x_2\right)& {{\mathrm{\&mu;}}_2}^4\left(x_2\right)\end{array}\right]=\left[\begin{array}{ccccc}1& 0& 0& 0& 0\\ 1& 0& 0& 0& 0\end{array}\right]$

Because the time period of image data is off-peak period, now the magnitude of traffic flow is less, and the change of speed to the volume of traffic is insensitive, therefore determines that the weight of density and speed is respectively 0.6 and 0.4, namely weight sets be W={0.6,0.4} therefore, section L can be obtained ₁₂running status fuzzy overall evaluation integrate as B={1,0,0,0,0}, i.e. unimpeded state.

The running status that we can obtain Ling Hu main road that uses the same method is:

The large road segment segment running status in table 6 water chestnut lake

Section	Running status	Section	Running status
				L 12	Unobstructed	L 21	Unobstructed
L 23	Unobstructed	L 32	Unobstructed
				L 34	Unobstructed	L 43	Unobstructed

Therefore can find out, section is all in unimpeded state, more identical with actual conditions.

In order to verify the evaluation of Urban Branch Road and subsidiary road, we select to see hill path and scape openings for the able and the worthy simulating, verifying.

By VISSIM simulation software, the data obtaining Liang Tiao road are as follows:

Table 7 scape openings for the able and the worthy and sight hill path running status

Section	Road type	Road section length	Density	Outlet running status
					Scape openings for the able and the worthy	Branch road	606m	2.3	Unobstructed
See hill path	Subsidiary road	599m	3.7	Unobstructed

With reference to above-mentioned computation process, be unobstructed state by calculating the running status obtaining this Liang Tiao road.

Claims (3)

1. adopt the Assessment of Serviceability of Roads evaluation method of fuzzy synthetic appraisement method, it is characterized in that:

For city expressway and major trunk roads, Road average-speed and traffic flow density two parameters are taked to carry out the foundation of evaluation index; Fuzzy comprehensive evoluation carries out as follows:

(1) set of factors U is set up: set of factors is the set that the factor composition of object is passed judgment in impact, i.e. U={u ₁, u ₂, u ₃, wherein u ₁, u ₂, u ₃represent that maximum queue length and the average per car of the saturation degree of crossing, each entrance driveway in crossing are incured loss through delay respectively;

(2) evaluation collection V is set up: evaluating collection is the set of estimator to the various possible judged result passed judgment on done by object, i.e. V={v ₁, v ₂, v ₃, v ₄, v ₅, wherein v ₁represent the unimpeded state in crossing, v ₂represent slight congestion state, v ₃represent congestion state, v ₄represent more crowded, v ₅represent seriously crowded;

(3) weight sets is set up: in order to characterize the significance level of each factor, corresponding weight should be given to each factor, forming weight sets W by each weight, being namely expressed as weight vector W={w ₁, w ₂, w ₃, each weight is answered normalization and is met nonnegativity condition, i.e. w ₁+ w ₂+ w ₃=1;

(4) single factor test fuzzy evaluation: single factor is evaluated from set of factors U, determines to pass judgment on object to evaluating the degree of membership concentrating each element; If pass judgment on object by when i-th factor is passed judgment in set of factors, a jth element v is concentrated to judge _ijdegree of membership be r _ij, then the available fuzzy set of result passed judgment on by i-th factor is expressed as:

$R_i=\frac{r_{i1}}{v_1}+\frac{r_{i2}}{v_2}+\frac{r_{i3}}{v_3}+\frac{r_{i4}}{v_4}+\frac{r_{i5}}{v_5}$

R is called single factor evaluation collection, simply can be expressed as R _i=(r _i1, r _i2, r _i3, r _i4, r _i5), the judge collection composition monofactorial Judgement Matrix by n factor:

$R=\left[\begin{array}{c}{R}_1\\ R_2\\ R_3\end{array}\right]=\left[\begin{array}{ccccc}{r}_{11}& r_{12}& r_{13}& r_{14}& r_{15}\\ r_{21}& r_{22}& r_{23}& r_{24}& r_{25}\\ r_{31}& r_{32}& r_{33}& r_{34}& r_{35}\end{array}\right]$

(5) fuzzy overall evaluation: when weight sets and singular index judgment matrix are all for determining known, carries out comprehensive evaluation by doing blurring mapping,

In formula, B is called fuzzy overall evaluation collection, and " o " represents a kind of fuzzy composition computing, and select M (o ,+) model, this Model Calculating Method is

$b_j=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{w}_i{r}_{\mathrm{ij}},j=\mathrm{1,2}...m$

B in formula _jbe called fuzzy overall evaluation collection, be called for short evaluation index, during for considering the affecting of all factors, evaluation object concentrates the degree of membership of i-th element to evaluating;

For city subsidiary road and branch road, traffic flow density is directly adopted to evaluate.

2. adopt the Assessment of Serviceability of Roads evaluation method of fuzzy synthetic appraisement method as claimed in claim 1, it is characterized in that, adopt trapezoidal membership function to set up membership function to evaluation index; Membership function is set up according to following evaluation criterion:

City expressway evaluation criterion one:

The road of design speed per hour 60km/h, traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 20 is slightly crowded,

Traffic flow density 25 ~ 35 is crowded,

Traffic flow density 45 ~ 60 is more crowded,

Traffic flow density >75 is seriously crowded;

The road of design speed per hour 70km/h and 80km/h, traffic flow density evaluation criterion is the same;

City expressway evaluation criterion two:

The highway of design speed per hour 60km/h, average velocity >55 is unimpeded,

Average velocity 50 ~ 40 is slightly crowded,

Average velocity 35 ~ 25 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <10 is seriously crowded;

The highway of design speed per hour 70km/h, average velocity >64 is unimpeded,

Average velocity 60 ~ 50 is slightly crowded,

Average velocity 40 ~ 30 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <10 is seriously crowded;

The highway of design speed per hour 80km/h, average velocity >72 is unimpeded,

Average velocity 65 ~ 55 is slightly crowded,

Average velocity 40 ~ 30 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <10 is seriously crowded;

Major urban arterial highway evaluation criterion one:

The road of design speed per hour 40km/h, traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 25 is slightly crowded,

Traffic flow density 35 ~ 45 is crowded,

Traffic flow density 55 ~ 65 is more crowded,

Traffic flow density >70 is seriously crowded;

The road of design speed per hour 50km/h and 60km/h, traffic flow density evaluation criterion is the same;

Major urban arterial highway evaluation criterion two:

The highway of design speed per hour 40km/h, average velocity >32 is unimpeded,

Average velocity 30 ~ 25 is slightly crowded,

Average velocity 20 ~ 15 is crowded,

Average velocity 10 ~ 5 is more crowded,

Average velocity <5 is seriously crowded;

The highway of design speed per hour 50km/h, average velocity >40 is unimpeded,

Average velocity 35 ~ 30 is slightly crowded,

Average velocity 25 ~ 15 is crowded,

Average velocity 10 ~ 5 is more crowded,

Average velocity <5 is seriously crowded;

The highway of design speed per hour 60km/h, average velocity >50 is unimpeded,

Average velocity 45 ~ 40 is slightly crowded,

Average velocity 35 ~ 25 is crowded,

Average velocity 20 ~ 10 is more crowded,

Average velocity <5 is seriously crowded;

City subsidiary road evaluation criterion:

Traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 25 is slightly crowded,

Traffic flow density 30 ~ 40 is crowded,

Traffic flow density 50 ~ 60 is more crowded,

Traffic flow density >70 is seriously crowded;

Urban Branch Road evaluation criterion:

Traffic flow density <10 is unimpeded,

Traffic flow density 15 ~ 20 is slightly crowded,

Traffic flow density 25 ~ 35 is crowded,

Traffic flow density 40 ~ 55 is more crowded,

Traffic flow density >60 is seriously crowded;

Wherein, traffic flow density unit a: km ^-1track ^-1, average velocity unit: kmh ^-1;

Membership function is as follows:

${{\mathrm{\&mu;}}_i}^0\left(u\right)=\left\{\begin{array}{cc}1& u\&le;u_{\mathrm{vs}}\\ \frac{u_s-u}{u_s-u_{\mathrm{vs}}}& u_{\mathrm{vs}}<u\&le;u_{\mathrm{sl}}\\ 0& u_{\mathrm{sl}}<u\end{array}\right.$

${{\mathrm{\&mu;}}_i}^1\left(x\right)=\left\{\begin{array}{cc}0& u\&le;u_{\mathrm{vs}}\\ \frac{u-u_{\mathrm{vs}}}{u_{\mathrm{sl}}-u_{\mathrm{vs}}}& u_{\mathrm{vs}}<u\&le;u_{\mathrm{sl}}\\ 1& u_{\mathrm{sl}}<u\&le;u_{\mathrm{sr}}\\ \frac{u_{\mathrm{ml}}-u}{u_{\mathrm{sr}}-u_{\mathrm{ml}}}& u_{\mathrm{sr}}<u\&le;u_{\mathrm{ml}}\\ 0& x>u_{\mathrm{ml}}\end{array}\right.$

${{\mathrm{\&mu;}}_i}^2\left(x\right)=\left\{\begin{array}{cc}0& u\&le;u_{\mathrm{sr}}\\ \frac{u-u_{\mathrm{sr}}}{u_{\mathrm{ml}}-u_{\mathrm{sr}}}& u_{\mathrm{sr}}<u\&le;u_{\mathrm{ml}}\\ 1& u_{\mathrm{ml}}<u\&le;u_{\mathrm{mr}}\\ \frac{u_{\mathrm{ll}}-u}{u_{\mathrm{mr}}-u_{\mathrm{ml}}}& u_{\mathrm{mr}}<u\&le;u_{\mathrm{ll}}\\ 0& x>u_{\mathrm{ll}}\end{array}\right.$

${{\mathrm{\&mu;}}_i}^3\left(x\right)=\left\{\begin{array}{cc}0& u\&le;u_{\mathrm{mr}}\\ \frac{u-u_{\mathrm{mr}}}{u_{\mathrm{ll}}-u_{\mathrm{lr}}}& u_{\mathrm{mr}}<u\&le;u_{\mathrm{ll}}\\ 1& u_{\mathrm{ll}}<u\&le;u_{\mathrm{lr}}\\ \frac{u_{\mathrm{vll}}-u}{u_{\mathrm{lr}}-u_{\mathrm{vll}}}& u_{\mathrm{lr}}<u\&le;u_{\mathrm{vll}}\\ 0& x>u_{\mathrm{vll}}\end{array}\right.$

${{\mathrm{\&mu;}}_i}^4\left(u\right)=\left\{\begin{array}{cc}0& u\&le;u_{\mathrm{vll}}\\ \frac{u-u_{\mathrm{vll}}}{u_s-u_{\mathrm{vs}}}& u_{\mathrm{vll}}<u\&le;u_{\mathrm{vlr}}\\ 1& u_{\mathrm{vlr}}<u\end{array}\right.$

Wherein, μ _i ⁰, μ _i ¹, μ _i ², μ _i ³, μ _i ⁴what represent is unimpeded, slightly crowded, crowded, more crowded, seriously crowded degree of membership, u _vsrepresent unimpeded critical value, u _slrepresent slightly crowded critical lvalue, u _srslightly crowded critical r value, u _mlrepresent crowded critical lvalue, u _mrrepresent crowded critical r value, u _llrepresent more crowded critical lvalue, u _lrrepresent more crowded critical r value, u _vllrepresent seriously crowded critical lvalue, u _vlrrepresent seriously crowded critical r value, u represents the traffic flow density or average velocity numerical value that collect.

3. adopt the Assessment of Serviceability of Roads evaluation method of fuzzy synthetic appraisement method as claimed in claim 1, it is characterized in that, step (3) described weight sets adopts gray theory method, analytical hierarchy process and the significance level of expert method to factor each in set of factors to carry out analytical calculation, obtains weight matrix.