Method for evaluating physical traffic accessibility
1. An assessment method of physical transportation accessibility for conducting an assessment for a study area in which physical transportation activity is present, the assessment method comprising:
dividing a research area into an evaluation area S and a peripheral area W, determining a boundary line of the evaluation area S, and dividing areas in which people exist and need to exist in the evaluation area S and the peripheral area W into a plurality of cells, wherein the boundary line does not cross any cell, the cell contained in the evaluation area S is defined as a cell needing evaluation, and the cell contained in the peripheral area W is defined as a cell participating in evaluation;
step two, determining the number M of cells contained in the evaluation area SSAnd cell number i, and the number of cells M contained in the peripheral zone WWAnd a cell number k;
determining the weight coefficient and the number of the cell, wherein the number of the weight coefficient is the same as the number of the corresponding cell;
determining a physical transportation mode aimed at evaluation, and setting a threshold time T of the road time corresponding to the physical transportation mode;
step five, determining a row distance r, which is defined as the product of the average speed corresponding to the physical transportation mode and a threshold time T;
step six, selecting a cell i in the evaluation area S0Taking the travel distance r as a radius as a circle center, thereby generating i taking a circumferential line as a side0A trip circle;
step seven, counting the number and the serial number of the cells contained in the trip circle, wherein the cells contained in the trip circle are defined as the cells with the cell center points within the circumference of the trip circle;
step eight, acquiring path network information in the travel circle, calculating according to the path network information and the average speed corresponding to the physical transportation mode, starting from the cell at the center of the circle, enabling the path with the shortest distance to reach other cells, and dividing the distance from the shortest path to the other cells by the average speed of the physical transportation mode to obtain the time required for reaching the other cells, or acquiring the time for the cell at the center of the circle to reach the physical transportation mode of the other cells through online map service, and then counting the number of the cells which can reach within a threshold time T and the number of the cells;
step nine, according to the data of the statistical result obtained in the step eight, combining the weight coefficient of the cell determined in the step three, calculating to obtain a cell i as the center of a circle0The reachability index of (a).
2. The evaluation method of claim 1, further comprising:
and repeating the sixth step to the ninth step until all cells in the evaluation area S are traversed, and then calculating the ratio of the number of weighted cells reachable by the travel circle of all the cells in the S area to the number of weighted cells reachable by the travel circle to obtain the overall reachability of the evaluation area S.
3. The evaluation method according to claim 1, wherein in step three, the weight coefficient of the cell is determined based on part or all of the room rate, the house rental rate, the population density, the living condition information, the business condition information, the available service information, and the employment information of the section where the cell is located.
4. The evaluation method according to claim 1, wherein in step four, the default value of the threshold time T is set in the range of 5 minutes to 30 minutes.
5. The assessment method according to claim 1, wherein the physical transportation means determined in step four comprises walking, cycling; and the number of the first and second electrodes,
and step five, setting the average speed for walking and bicycles by using default values or average speed values calculated based on measured or map service data.
6. The evaluation method according to claim 1, wherein in step seven, i is counted0When the cell number and the cell number contained in the trip circle are reached, the following two situations are divided:
under the first situation, all the cells contained in the trip circle are located in the assessment area S, the cell number contained in the trip circle directly adopts the cell number of the assessment area S, and the cell number is
In case two, when a part of cells included in the trip circle are in the peripheral area W, the cell number i of the evaluation area S is adopted by the cell in the evaluation area S, the cell number k of the peripheral area W is adopted by the cell in the peripheral area W, and the number of the cells included in the trip circle and belonging to the evaluation area S is respectively countedAnd the number of cells belonging to the peripheral zone W
7. The evaluation method according to claim 6, wherein one cell i as a circle center of a trip circle is calculated based on the following formula (1) and formula (2)0Of the reachability index, wherein
In formula (1)Andthe following definitions are used:
and, the number of weighted cells reachable within the circle is calculated according to the following formula (2)Number of weighted cells occupying all of the circleSpecific gravity ofAs a starting cell i0The index of the reachability of (a) is,
wherein
After the reachability indexes of all cells in the S area are calculated in a traversing mode, the ratio of the number of the weighted cells reachable by the trip circle of all the cells in the S area to the number of the weighted cells of the trip circle is calculated to obtain the reachability index of the whole evaluation areaNamely, it is
Wherein
Background
Physical transportation refers to land travel transportation using a human-powered method such as walking or bicycle. The bicycle refers to a pedal bicycle driven by manpower, and does not comprise a booster.
However, there is a lack in the art of a solution that can help researchers to fully and consistently assess, compare or study physical traffic accessibility or the degree of convenience in different areas. Due to the lack of related solutions, quantitative decision analysis basis is often lacked when physical transportation network planning or planning and designing of urban slow-moving systems and the like are carried out at present. Making better public decisions is not facilitated.
Therefore, there is a need for a method for evaluating the accessibility of physical transportation to make up for the above-mentioned deficiencies of the prior art.
Disclosure of Invention
The invention aims to solve the technical problem that a novel method for evaluating physical traffic accessibility is provided in order to overcome the defect that a solution which can help researchers comprehensively and consistently evaluate, compare or research physical traffic accessibility or convenience degrees in different areas is lacked in the prior art, so that the urban and rural planning design is not considered enough in the aspect of a slow-moving network.
The invention solves the technical problems by adopting the following technical scheme in a research area where a physical traffic path network can be obtained:
the invention provides an evaluation method of physical transportation accessibility, which comprises the following steps:
dividing a research area into an evaluation area S and a peripheral area W, determining a boundary line of the evaluation area S, and dividing areas in which people exist and need to exist in the evaluation area S and the peripheral area W into a plurality of cells, wherein the boundary line does not cross any cell, the cell contained in the evaluation area S is defined as a cell needing evaluation, and the cell contained in the peripheral area W is defined as a cell participating in evaluation;
step two, determining the number M of cells contained in the evaluation area SSAnd cell number i, and the number of cells M contained in the peripheral zone WWAnd a cell number k.
Determining the weight coefficient and the number of the cell, wherein the number of the weight coefficient is the same as the number of the corresponding cell;
determining a physical transportation mode aimed at evaluation, and setting a threshold time T of the road time corresponding to the physical transportation mode;
step five, determining a row distance r, which is defined as the product of the average speed corresponding to the physical transportation mode and a threshold time T;
step six, selecting a cell i in the evaluation area S0(i0A certain number of i) as the center of the circle, and taking the travel distance r as the radius to generate i with a circumference line as the side0A trip circle;
step seven, counting the number and the serial number of the cells contained in the trip circle, wherein the cells contained in the trip circle are defined as the cells with the cell center points within the circumference of the trip circle;
step eight, acquiring path network information in the travel circle, calculating according to the path network information and the average speed corresponding to the physical transportation mode, starting from the cell at the center of the circle, enabling the path with the shortest distance to reach other cells, and dividing the distance from the shortest path to the other cells by the average speed of the physical transportation mode to obtain the time required for reaching the other cells, or acquiring the time for the cell at the center of the circle to reach the physical transportation mode of the other cells through online map service, and then counting the number of the cells which can reach within a threshold time T and the number of the cells;
and step nine, calculating the accessibility index of the cell serving as the circle center according to the result data obtained in the step eight and by combining the weight coefficient of the cell determined in the step three.
According to some embodiments of the invention, the method of assessing further comprises:
and repeating the sixth step to the ninth step until all cells in the evaluation area S are traversed, and then obtaining the overall reachability of the evaluation area S based on the ratio of the number of weighted cells reachable by the travel circle of all the cells in the evaluation area S to the number of all weighted cells of the travel circle.
According to some embodiments of the present invention, in step three, the weight coefficient of the cell is determined based on part or all of the room price, the house rental price, the population density, the living condition information, the business condition information, the available service information, and the employment information of the section where the cell is located. If the factor is ignored, the weight coefficient may be set to 1.0.
According to some embodiments of the invention, in step four, the default value of the threshold time T is set in the range of 5 minutes to 30 minutes.
According to some embodiments of the invention, the physical mode of transportation determined in step four comprises walking, cycling; and the number of the first and second electrodes,
and step five, default values of average speed are set for walking and bicycles, or average speed values calculated based on the measured path distance and time of the physical transportation mode provided by the online map service are used.
According to some embodiments of the invention, in step seven, i is counted0When the cell number and the cell number contained in the trip circle are reached, the following two situations are divided:
under the first situation, all the cells contained in the trip circle are located in the assessment area S, the cell number contained in the trip circle directly adopts the cell number of the assessment area S, and the cell number is
In case two, when a part of cells included in the trip circle are in the peripheral area W, the cell number i of the evaluation area S is adopted by the cell in the evaluation area S, the cell number k of the peripheral area W is adopted by the cell in the peripheral area W, and the number of the cells included in the trip circle and belonging to the evaluation area S is respectively countedAnd the number of cells belonging to the peripheral zone W
According to some embodiments of the present invention, one cell i as a circle center of a trip circle is calculated based on the following formula (1) and formula (2)0∈MSThe number of weighted cells reachedIs defined by the following formula (1),
in formula (1)Andthe following definitions are used:
and, the number of weighted cells reachable within the circle is calculated according to the following formula (2)Number of weighted cells occupying all of the circleSpecific gravity ofAs a starting cell i0The index of the reachability of (a) is,
wherein
In the formula, biFor the weight coefficient of the i numbered cells in the evaluation zone S, i belongs to MSAnd b iskNumbering the weight coefficients of the cells for k in the peripheral zone W, k belonging to MW。
The above-mentioned weighted cell count means the equivalent cell count obtained by assigning a weight coefficient to a cell, and if there is a cell, the cell corresponds to 1.5 cell counts and some cells correspond to only 0.5 cell counts.
On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.
The positive progress effects of the invention are as follows:
according to the assessment method for the physical transportation accessibility, the researchers can be helped to comprehensively and consistently assess, compare or research the physical transportation accessibility or the convenience degree of different areas, and therefore better public decisions can be made in an auxiliary mode.
Drawings
Fig. 1 is a flowchart illustrating a method for evaluating physical transportation reachability according to a preferred embodiment of the present invention.
Detailed Description
The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, is intended to be illustrative, and not restrictive, and any other similar items may be considered within the scope of the present invention.
In the following detailed description, directional terms, such as "left", "right", "upper", "lower", "front", "rear", and the like, are used with reference to the orientation as illustrated in the drawings. The components of various embodiments of the present invention can be positioned in a number of different orientations and the directional terminology is used for purposes of illustration and is in no way limiting.
The method of assessing physical transportation accessibility according to a preferred embodiment of the present invention may be used to conduct assessments for areas of study where physical transportation activity is present.
As shown in fig. 1, the evaluation method includes the steps of:
dividing a research area into an evaluation area S and a peripheral area W, determining a boundary line of the evaluation area S, and dividing the evaluation area S and the peripheral area W into a plurality of cells, wherein the boundary line does not cross any cell, the cell contained in the evaluation area S is defined as a cell to be evaluated, and the cell contained in the peripheral area W is defined as a cell participating in evaluation;
step twoDetermining the number M of cells contained in the evaluation area SSAnd cell number i, and the number of cells M contained in the peripheral zone WWAnd a cell number k;
determining the weight coefficient and the number of the cell, wherein the number of the weight coefficient is the same as the number of the corresponding cell;
determining a physical transportation mode aimed at evaluation, and setting a threshold time T of the road time corresponding to the physical transportation mode;
step five, determining a row distance r, which is defined as the product of the average speed corresponding to the physical transportation mode and a threshold time T;
step six, selecting a cell i in the evaluation area S0Taking the travel distance r as a radius as a circle center, thereby generating i taking a circumferential line as a side0A trip circle;
step seven, counting the number and the serial number of the cells contained in the trip circle, wherein the cells contained in the trip circle are defined as the cells with the cell center points within the circumference of the trip circle;
step eight, acquiring path network information in the travel circle, calculating according to the path network information and the average speed corresponding to the physical transportation mode, starting from the cell at the center of the circle, enabling the path with the shortest distance to reach other cells, and dividing the distance from the shortest path to the other cells by the average speed of the physical transportation mode to obtain the time required for reaching the other cells, or acquiring the time for the cell at the center of the circle to reach the physical transportation mode of the other cells through online map service, and then counting the number of the cells which can reach within a threshold time T and the number of the cells;
step nine, according to the result data obtained in the step eight, combining the weight coefficient of the cell determined in the step three, calculating to obtain a cell i as the center of a circle0The reachability index of (a).
According to some preferred embodiments of the invention, the method of evaluating further comprises:
and repeating the sixth step to the ninth step until all cells in the evaluation area S are traversed, and then obtaining the overall reachability of the evaluation area S based on calculating the ratio of the number of weighted cells reachable by the travel circle of all cells in the evaluation area S to the number of weighted cells reachable by the travel circle, that is, step ten shown in the figure.
Where it is understood that there is accessibility to traffic. Reachability can be understood as the range of zones that can be reached under the constraint of the travel time threshold T, with greater ranges being better. Physical traffic due to body force limitations, the travel range is limited to the areas within the circle that need to be reached, and the best accessibility is achieved if all these areas within the circle can be reached within a threshold time.
In the physical traffic accessibility evaluation, the area of study is divided into an evaluation zone S and a peripheral zone W outside the evaluation zone S. In S region, there is MSThe number i belongs to the MS(ii) a In W region there is MWA cell for auxiliary evaluation is endowed with a number k belonging to MW. The physical transportation mode has a proper travel distance r, usually the walking is within 2km, the pedal bicycle is within 5km, and most people feel tired after the walking. For evaluation, a physical transportation mode is selected in zone S, and a cell i is selected0∈MSAs a center, a circular range with r distance as radius is drawn to form i0And (4) going out of the circle, and completely enclosing the cells with the cell center points within the circumference line. Because the district of starting out is in the centre of a circle of going out to radius distance r equals physical transportation mode speed x threshold value time T, the district of starting out only can satisfy the restriction of journey time to the edge of going out circle with straight-line distance like this, consequently, the circle of going out actually sets up the highest reachability target that can reach in the threshold value time for the district of starting out.
Trip circle is due to central district i0The positional relationship may be entirely in the S-zone, or may be across the S-zone and the W-zone near the boundary of the S-zone. When all the cells in the trip circle are S cells, the number of the cells in the circle isThe cell adopts the cell number i of the S cell; when the travel circle has W cells, the number of the cells in the circle isAnd the cell in the intersection of the trip circle and the S area adopts the cell number i of the S area, and the cell in the intersection of the trip circle and the W area adopts the cell number k of the W area.
According to some preferred embodiments of the present invention, in step three, the weight coefficient of the cell is determined based on part or all of the room price, the house rental price, the population density, the living condition information, the business condition information, the available service information, and the employment information of the section where the cell is located. If the factor is ignored, the weight coefficient may be set to 1.0.
It will be appreciated that the preferred embodiment described above is based on the recognition that accessibility is also an opportunity to gain value. The value of the cells may vary due to differences in residential, commercial, service, employment, etc. of the segment in which each cell is located. The difference of the cell values is expressed by weight coefficients, and the weight coefficients are larger when the values are higher. Let biIs the weight coefficient of the i cell of the S cell, i belongs to MS;bkIs the weight coefficient of the k cells of the W area, k belongs to MW. Thus, reaching a high weight cell is equivalent to reaching a high value cell. When the number of arriving cells is the same, the number of arriving high-value cells is large, and the chance of obtaining value is high.
According to some preferred embodiments of the present invention, in step seven, i is counted0When the cell number and the cell number contained in the trip circle are reached, the following two situations are divided:
under the first situation, all the cells contained in the trip circle are located in the assessment area S, the cell number contained in the trip circle directly adopts the cell number of the assessment area S, and the cell number is
In case two, when a part of cells included in the trip circle are in the peripheral area W, the cell number i of the evaluation area S is adopted by the cell in the evaluation area S, the cell number k of the peripheral area W is adopted by the cell in the peripheral area W, and the number of the cells included in the trip circle and belonging to the evaluation area S is respectively countedAnd the number of cells belonging to the peripheral zone W
According to some preferred embodiments of the present invention, one cell i as a center of a circle of travel is calculated based on the following formula (1) and formula (2)0∈MSOf the reachability index, wherein
In formula (1)Andthe following definitions are used:
and, the number of weighted cells reachable within the circle is calculated according to the following formula (2)Number of weighted cells occupying all of the circleSpecific gravity ofAs a starting cell i0The index of the reachability of (a) is,
wherein
In the formula, biFor the weight coefficient of the i numbered cells in the evaluation zone S, i belongs to MSAnd b iskNumbering the weight coefficients of the cells for k in the peripheral zone W, k belonging to MW。
It should be understood that the above-mentioned weighted cell number refers to the equivalent cell number after the cells are given the weight coefficients, and if there are cells, the number of the cells is 1.5, and if there are cells, the number of the cells is only 0.5.
The above preferred embodiment is explained below in the context of mathematical modeling.
Expressed by a mathematical model, imagine i from within the evaluation zone S0∈MSStarting from a cell, forming a cell with i0I with cell as center and r distance as radius0The travel circle is a physical transportation mode, and the number of weighted cells in the circle can be reached within the T threshold value time isNamely, it is
Wherein i belongs to the S area cell number in the intersection of the trip circle or the trip circle and the S area, k belongs to the W area cell number in the intersection of the trip circle and the W area, and
normalizing the result, and counting the number of the reachable weighted cells in the circle within the time TNumber of weighted cells occupying all of the circleSpecific gravity ofAs a starting cell i0An index of accessibility, i.e.
Wherein
After the reachability indexes of all cells in the S area are calculated in a traversing mode, the ratio of the number of weighted cells reachable by the trip circle of all the cells in the S area to the number of weighted cells of the trip circle is calculated to obtain the reachability index of the whole evaluation areaNamely, it is
Wherein
The formula (3) balances the scale difference of the areas needing to be reached in all travel circles, so that the scale of the areas is positively correlated with the contribution degree of the total accessibility index, and the larger the scale is, the larger the influence is. The reachability index values of the cells and the evaluation zones are between 0 and 100 percent, and the higher the index is, the better the reachability is.
The above-mentioned weighted cell count is an equivalent cell count to which a weight coefficient is given, and some cells correspond to 1.5 cell counts and some cells correspond to only 0.5 cell counts.
Therefore, by traversing all cells of the assessment area by the departure place in a physical transportation mode, the threshold time T and the travel distance radius r, the reachability indexes of the cells and the whole assessment area can be obtained. By comparing indexes, the advantages and the defects of each cell unit on physical transportation can be analyzed.
According to some preferred embodiments of the invention, in step four, the default value of the threshold time T is set in the range of 5 minutes to 30 minutes.
According to some preferred embodiments of the invention, the physical mode of transportation determined in step four includes walking, cycling; and the number of the first and second electrodes,
and step five, setting default values of average speed for walking and bicycles, or using average speed values obtained based on measured or calculated map service data, such as walking default value of 4km/h and bicycle default value of 8 km/h.
According to the assessment method of the physical transportation accessibility, provided by the invention, a quantitative and objective assessment method of the physical transportation in different areas is provided, so that researchers can be helped to comprehensively and consistently assess, compare or research the physical transportation accessibility or the convenience degree in different areas, and better public decision can be assisted. For example, when planning and designing a walking system, a bicycle lane system, or the like, researchers can use the above-described evaluation method for physical transportation accessibility, which is beneficial to comprehensively and objectively consider the accessibility and convenience of physical transportation modes in each area and perform comparative analysis of different areas.
While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that these are by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.