iBusiness, 2013, 5, 167-172
Published Online December 2013 (http://www.scirp.org/journal/ib)
Open Access IB
Research on Routing Optimization of Regional Logistics
Based on Gravity Model: A Case of Blue and Yellow Zones*
Haiqing Hu, Yang Li
Shandong Yingcai University, Jinan, China.
Email: huhqkelly@163.com, cnjnly@163.com
Received November 4th, 2013; revised November 20th, 2013; accepted December 5th, 2013
Copyright © 2013 Haiqing Hu, Yang Li. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The structure is the basic attribute of everything. The structure of logistics network is composed of logistics nodes and
logistics routes, however the logistics cost mainly happens on the function the logistics route undertakes. So logistics
routing optimization is the key to reduce logistics cost. As logistics is the hygiene factor of regional economic devel-
opment, this article studied on logistics routing optimization by applying the demand of the regional economic devel-
opment as a starting point, using the spatial interaction theory, building a method of the regional logistics link optimiza-
tion based on the gravity model, and taking blue and yellow zones as the background to illustrate the rationality and
feasibility of this method.
Keywords: Gravity Model; Routing Optimization; Blue and Yellow Economic Zones; Logistics Network
1. Introduction
Logistics is the hygiene factor of social and economic
development, so the regional logistics must meet the de-
mand of the regional economic development. As a basic
economic activity, logistics is also one of industries con-
stituting the regional economy. Seen in this light, the
logistics of the regional economic development is not
only a hygiene factor, but also an incentive factor of the
regional economic development. So first of all, logistics
should be set as the security condition of the regional
economic development and secondly it can be an indus-
try as a key support in the area with logistics advantages.
Structure is the basic attribute of everything. Accord-
ing to the system science, it is relatively stable contact
way of the inhere nt manifestations of organization al pro-
cedures and temporal relationship between the various
elements within the system. Logistics network structure
is the basic problem of the logistics network. It is com-
posed of logistics nodes and logistics routes. Logistics
nodes assume the function of logistics pauses while lo-
gistics routes assume the function of logistics spatial
transference, logistics activities of transport and delivery
carried out on the routing distribution, and transportation
costs account for a majority of logistics costs, so the lo-
gistics routing optimization is the key to reduce logistics
costs [1]. Based on the logic above, this article proposed
ideas and methods of optimizing logistics routes by using
the spatial interaction theory and demonstrated the prac-
ticality and feasibility of this method through analyzing
the case of logistics routing optimization of blue and yel-
low zones.
2. Theoretical Basis
Regional logistics should be able to meet the needs of
regional economic development at first based on the rela-
tionship between regional logistics and regional economy.
Region involves a number of economies, the spatial in-
teraction theory is a basic theory of explaining economic
spatial linkage between economies, it mainly studies on
locating potential energy, regional polarization and dif-
fusion mechanism, spatial interaction model as well as
the change and effect of factor flow. This theory can be
used to explain whether the association exists, associa-
tion strength and how to associate relevance between
cities, between city and region , between regions, in addi-
tion the influence and influencing factors of the associa-
tion strength and association way in the spatial system.
*Supported by Shandong Province, College of Humanities and Social
Science Research Program (No. J13WG58) and Zhejiang Provincial
atural Science Foundation (No. 13YJC630221). The gravity model is a mathe matical expression of the
Research on Routing Optimization of Regional Logistics Based on Gravity Model: A Case of Blue and Yellow Zones
spatial interaction theory. Gravitational interaction be-
tween cities is a key element of the gravity model. The
urban flow is the economic activity generated by connec-
tion outside and the intensity of the urban flow is used to
measure the connection of city from the outside world.
The intensity of urban flow refers to the energy generated
by urban extroverted function (agglomeration and radia-
tion) and the number of mutual influence relations be-
tween cities. In this paper, we adopted the urban flow
intensity to represent th e force between single city an d its
adjacent city. Specific formula is:
F means the intensity of urban flow, N means the city
functional benefit, it is the actual impact generated by
unit extroverted function among cities, E means urban
extroverted function, it is composed of economic activity
generated by the city contacting with the outside world.
Considering the representation of indicators and data
availability, this paper adopts the practitioners engage in
export-oriented economic activity as indicators of the
amount of urban functions. It is represented by the loca-
tion quotient engaging in export-oriented economic ac-
tivity. Specific formula is:
1, 2,,;1, 2,,
ij i
ij j
Lqin jm
 
If , city department j do not have external
function, ; If city department
do have external function, because the allocation propor-
tion of practitioners exceed the national allocation pro-
portion, it can provide services outside the city area.
Thus, the extern al fun ction of city department can
be expressed as:
Lq ij
ijiji j
EGGGG (3)
So the total amount of extroverted function of m de-
partments in city is:
The function efficiency of city can be expressed by
GDP per capit a: i
So the intensity of urban flow of city is:
iii iii
Defining the distance is another key factor of the grav-
ity model, under the condition of market economy, the
distance has alienated to the combination concept of
monetary cost and time cost .Therefore, distance can be
expressed as [2]:
ijij ij ij
Including means the th way of transportation
between and ; ij
i i
means the weight of the ith
way of transportation between and ; ij means
the monetary cost of the th way of transportation be-
tween and ; ij means the time cost the th way
of transportation between and .
3. Study Design
The general idea about routing optimization of regional
logistics can be summarized as: The regional logistics
routing optimization should be based on the logistics
demand volume, according to the logistics demand vol-
ume, we can determine the regional logistics demand,
then determine the supply ability of regional logistics
route in light of the road traffic conditions. In the end,
optimization recommendations can be put forward based
on the matching of demand and supply situation of logis-
tics route.
3.1. Logistics Demand Analysis
Regional logistics demand should include two parts, the
first is to grasp the current logistics demand, and the
second is the logistics demand forecast for the future.
Considering the regional logistics demand is in order to
meet the needs of the development of regional economy
at first. When it comes to intra-region or inter-city, its
logistics flow in a certain degree can represent the
strength of the association between cities or within re-
gion, and the gravity model which belongs to the spatial
interaction theory can reflect the strength of the associa-
tion between cities or within region in order to measure
the correlation between cities in th e region. Then we can
use the industrial structure analysis method (location
quotient) to study the leading industry of the cities in the
area, according to the leading industry to determine the
main city logistics functional requirements, finally, ana-
lyzing the relation between the city industry cooperation
to determine the city logistics demand at present, also in
the future by setting high degree of correlation city as the
3.2. Investigation of Logistics Supply
To conduct a full in vestigation of the city logistics supply
situation in the region, the investigation content includes
the current logistics infrastructure supplies and the plans
for the future supplies. Current supply situ ation is mainly
to analyze the overview of the main logistics corridor in
the region and to analyze main logistics nodes. Logistics
activities of the logistics nodes are mainly concentrated
in the logistics park, and the logistics node should be
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Research on Routing Optimization of Regional Logistics Based on Gravity Model: A Case of Blue and Yellow Zones 169
highlighted in the general situation of logistics park. The
future supplies mainly based on the planning of regional
and intra-regional city logistics.
3.3. Optimizing Opinion
Intra-regional correlation close ties to the city industry,
the logistics route supply present situation and the future
plan is the basis of the regional logistics routing optimi-
zation. Experience measures suitable for this region can
be refined to put forward the regional logistics routing
optimization and improvement opinions through analyz-
ing and summarizing the su ccessful cases of international
and domestic regional logistics.
4. Application Example
In 2009 the state council approved the Yellow River
delta efficient ecological economic zone development
planning, and in 2011 approved the Shandong peninsula
blue economic zone planning. So far the integrative de-
velopment of the blue and yellow economic zone has
become the focus of atten tion from all walks of life and it
is also inseparable from the support of modern logistics.
So this article took the optimization of the blue and yel-
low zone logistics route to illustrate the ap plicability and
feasibility of the gravity model.
4.1. Urban Gravity of the Blue and Yellow
Economic Zone
Using export-oriented department practitioner index to
measure the intensity of urban flow, urban flow intensity
of Dongying ,Weifang, Dezhou is higher, it shows that
the export-oriented economy of the city, in addition to
meeting the local needs and more surplus capacity to
undertake external demand.
There are four main modes of transportation between
cities, highway transportation, railway transportation,
water transport and air transport, and yellow blue eco-
nomic zone is in the range of road transportation eco-
nomic mileage, a large number of transportation is as-
sumed by road transportation in the blue yellow eco-
nomic zone, so this article selected the inter-city highway
as basis of the main distance. Distance formula can be
expressed as:
ijij ij
dcT (8)
Including ij means the monetary cost of the road
transportation between i and j; ij means the time cost
of the highway transportation between i and j.
Monetary cost of highway transportation was ex-
pressed by road freight rate, nearly three months of 218
times transport data was collected through the transporta-
tion enterprise investigation. Statistics showed that the
road freight rate floating 0.20 yuan/ton.Km nearby, of
which 71% of freight rate fluctuating in the rang e of 0.20
+ 0.02, the concentration degree of the freight rate was
higher. The remaining 29% of the data was divided into
two groups, higher than the average and below average.
It was found that the higher freight rate in respects of
transportation distance had significant difference with the
rest of the sample. Then, regression analysis was carried
out on the transportation by using the transportation dis-
tance and vehicle type, etc. It was found that the coeffi-
cient of determination was as high as 95%, after the
variable vehicle type added, the coefficient of determina-
tion increased less than 1%. So it can be seen that trans-
portation cost mainly related to the transportation dis-
tance. According to the results of regression, the mone-
tary cost of transportation is a function of the transport
distance and it can be concretely expressed as:
ij ij
Including ij means the actual physical distance
between i and j.
This article used baidu map (http://map.baidu.com) to
query the distance between i and j. As the distance was
the main factors influencing the transport monetary cost,
this article chose the shortest distance between i and j as
query condition s when qu erying on th e b aidu map, in th is
way, the distance between city and city in the blue yel-
low economic zone can be obtained. At the same time,
Shandong province traffic tourist map published by map
publishing house of Shandong provin ce in 2012 was also
collected to verify the accuracy.
Vehicle running speed is important influence factor in
the vehicle operating costs, and the main factor influenc-
ing the vehicle running speed is road technology level.
As the roads with different technology levels have dif-
ferent requirements in the design of surface evenness,
Slope, turning radius, the higher the road technical level
is, the faster the speed is, and the greater the impact made
on operating costs [3]. According to the road technology
standard of the People’s Republic of China (JTGB01~
2003) which regulated different types of road driving
speed, and combined with the blue economic zone road
actual situation, set the highway 120 km/h, state road 80
km/h, provincial highway and the following road 60
km/h. The freight time (unit: h) between cities can be
calculated by Using the various road mileage between
each city.
According to the gravitational model of cities, setting
urban flow intensity as the interaction force of each city,
using the distance between the cities, computing th e mu-
tual attraction between cities, Table 1 can be obtained.
From Table 1, the gravity of cities in the blue an d yel-
low economic zone in total to Weifang, Dongying, De-
zhou, Qingdao, Rizhao, Yantai, Zibo, Weihai in a de-
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Research on Routing Optimization of Regional Logistics Based on Gravity Model: A Case of Blue and Yellow Zones
Open Access IB
Table 1. Attraction betwee n citie s in blue and yellow ec onomic zone.
City Qingdao Yantai Weifang Rizhao Weihai Dongying Zibo Dezhou
Qingdao - 17.41 67.64 71.25 4.50 33.45 2.06 25.54
Yantai 17.41 - 19.00 8.73 30.06 12.82 0.86 8.77
Weifang 67.64 19.00 - 34.16 4.55 181.07 11.03 167.96
Rizhao 71.25 8.73 34.16 - 2.23 23.88 1.98 16.08
Weihai 4.50 30.06 4.55 2.23 - 3.53 0.26 2.47
Dongying 33.45 12.82 181.07 23.88 3.53 - 32.63 167.97
Zibo 2.06 0.86 11.03 1.98 0.26 32.63 - 32.65
Dezhou 25.54 8.77 167.96 16.08 2.47 167.97 32.65 -
Table 2. City characteristic industry in the primary indus-
scending order, after taking the city distance in to account,
certain differences existed in the evaluation of th e sorting
result with urban flow intensity. In addition, from the
point of gravity between cities (such as the bold cells in
Table 1), two big gravity group formed, one is centered
in Qingdao, and the gravity linear group was composed
of the gravity between Qingdao and Weifang, also the
gravity between Qingdao and Rizhao. Another one made
the gravity between Weifang and Dezhou, and the grav-
ity between Weifang and motivation coherent, formed a
closed gravity group through the relationships between
Dongying and Dezhou. As shown in th e Figure 1.
City Characteristic industry
Dongying cotton
Weihai fishery
Yantai fruit nut beverage
Qingdao fishery
Zibo flowers and other horticultural crops
Binzhou cotton
Rizhao oil
Dezhou livestock
Weifang vegetable
4.2. Urban Industries and Logistics Demand
Research on Blue and Yellow Economic
4.2.1. Blue and Yellow Economic Zone Primary
Industry Characteristics and the Logistics
1) The primary industry characteristic industry analy-
From the perspective of industry specialization and
scale, Dongying and Bin zhou’s cotton industry, W eihai’s
fisheries, Rizhao’s oil industry, Yantai’s fruit nut bever-
age industry and Dezhou’s livestock industry have ad-
vantage in industry specialization and scale. Although
the specialization of Qingdao’s fisheries and Weifang’s
vegetables is not very prominent, ratio exceeded 20% in
the primary industry of Qingdao and Weifang. Flowers
and other horticultural compared with other agricultural
industry in Zibo, the scale degree is not high, but com-
pared with other cities, professional advantages are very
obvious. From this view, the leading industries of blue
and yellow zone cities primary industry are respectively
shown in Table 2.
Figure 1. Gravity group of blue and yellow economic zone.
of Weifang, Dongying and Dezhou covers four cities
(Weifang, Dongying, Binzhou and Dezhou), and Wei-
fang, Dongying, Binzhou and the county Laoling and
Qingyun belong to the categor y of yello w econo mic zone.
In view of the situation of urban agriculture industry lo-
2) Agricultural Cooperation Analysis
The first group (Weifang-Dongying-Dezhou) analysis
of the agricultural coo peration: The first grou p composed
Research on Routing Optimization of Regional Logistics Based on Gravity Model: A Case of Blue and Yellow Zones 171
4.2.2. Blue and Yellow Economic Zone Secondary
Industry Characteristics and the Logistics
cation quotient in the blue and yellow economic zone, the
agricultural characteristic industries of Weifang, Dong-
ying, Dezhou respectively are vegetables, cotton and
livestock. Vegetables and livestock sales link needs the
support of cold chain logistics, so it is suggested that the
cold chain logistics system should be established and
developed in the first group (It was consistent with the
cold storage needs of ecological animal husbandry in-
dustry chain which was in mentioned the Dongying 12th
five-year plan). Dongying and Binzhou’s cotton advan-
tage is obvious, and the Binzhou’s textile industry loca-
tion quotient is higher in its secondary industry, so the
integrative development of the primary industry and the
secondary industry can be formed in the first group. Bin-
zhou’s textile industry sho uld be set as the core to estab-
lished industrial chain (cotton production—cotton proc-
essing—sale). The additional value of cotton can be im-
proved through the textile and the industry chain can ex-
tend forwards and backwards. Backward can develop bam-
boo forest planting (Binzhou Haosheng Group which has
industrial base), forwar d can develop clothing industry.
1) The secondary industry characteristic industry ana-
The proportion of each city industry in its secondary
industry shows the scale of the industry in this city, and
the location quotient of the blue and yellow zone shows
the degree of specialization of the industry in the region.
Considering the double perspective (Specialization and
scale), the main industries of cities are shown in Table 3.
2) The secondary industry grou p cooperation analysis
The first group (Weifang-Dongying-Dezhou) analysis
of the industry cooperation: As the degree of specializa-
tion of agricultural products and byproducts process is
only 0.8, it is necessary to continue improving its indus-
try specialization, but th e specialization of indu stry needs
a process. Therefore, in the short term, the agricultural
products and byproducts processing of Binzhou need to
rely on the processing capacity of Weifang.
The second group (Weif ang-Qingdao-Rizhao) analysis
of the industry cooperation: The black metal smelting
and rolling processing industry of Rizhao have not yet
been forming, the location quotient is only 0.1 which
cannot be self-sufficient. And the location quotient of
ferrous metals mining and dressing is 11.91. When it
comes to Zibo, the location quo tient is 6.02, but the lo ca-
tion quotient of the Black metal smelting and rolling
processing is 2.61. Compared with Zibo, the scale of
The second group (Weif ang-Qingdao-Rizhao) analysis
of the agricultural cooperation: Qingdao characteristic
agriculture is fishery, it also needs the support of cold
chain logistics to achieve high additional value. So the
cold-chain logistics network of the first group is sup-
posed to extend to Qingdao, Form cold chain logistics
network system that its core logistics node is Weifang,
main logistics nodes are Qingdao, Weifang and Dezhou.
Table 3. Main industries of cities in sec o ndary industry .
City Both specialty and strength
Qingdao Developmental Emphases: transportation equipment manufacturing industry;
Electrical machinery and equipment manufacturing industrialization
Yantai Communication equipment, computers and other electronic devices; Non-ferrous metal smelting and rolling
processing industry; Developing the nonferrous me t al industry acquisi tion and processing of industrialization
Weihai Manufacture of Rubber, artware and other Manufacturing, Agricultural Products and Byproducts Processing; Promoting
instrumentation of cultural and educational sporting goods manufacturing and cultural office machinery manufacturing scale
Rizhao Ferrous Metals Mining and Dressing, Wood processing and products, Metal ProductsElectric heat production and
supply industry, agricultural Products and Byproducts Processing; Improving the degree of specialization food processing
Dongying Petroleum and Natural Gas Extraction, Oil processing and coking and nuclear fuel processing industry,
Chemical raw materials and chemical manufacturing, Rubber pr oducts Develo pmental Emphases:
Oil production, processing and deep processing industry industrialization
Weifang Developmental Emphases: Industrialization of agricultural food processing
Binzhou Textiles, leather and fur feathers (fine hair) and manufacturing Developmental Emphases: Textile industry industrialization
Zibo Chemical raw materials and chemical manufacturing; Nonmetal Mineral Products;
Oil processing and coking and nuclear fuel processing industry
Dezhou Extractive industry
Open Access IB
Research on Routing Optimization of Regional Logistics Based on Gravity Model: A Case of Blue and Yellow Zones
In addition, except the logistics routes, the logistics
node construction should be given full consideration to
the group cooperation between two cities, Such as the
demand for cold chain logistics network in the group
cooperation of primary industry, and the demand for
railway logistics network in the group cooperation of
secondary industry.
Rizhao black metal smelting and rolling processing in-
dustry is too small and metal logistics co st is higher, so it
is the best way to process nearby. As Rizhao is close to
Qingdao, it is the lowest logistics cost strategy to choose
Qingdao as downstream processing site of the black
metal smelting and rolling processing.
From the perspective of the cooperation of the first
group and second group, it is prominent in the first group
that Binzhou cooperates with Weifang and it is the same
with the cooperation of Qingdao and Rizhao in the sec-
ond group. Because the distance between Binzhou and
Weifang is close as well as Qingdao and Rizhao, which
is in the range of road transportation economic mileage,
it is necessary to strengthen the road transport capacity
between Binzhou and Weifang, Rizhao and Qingdao.
4.3. The Present Situation of Logistics Supply of
Blue and Yellow Economic Zone
The distance between cities in the main group which be-
long to the blue yellow economic zone can be obtained,
as shown in Table 4.
4.4. Blue and Yellow Zone Logistics Route
Optimization Suggestions
From the distance between main group cities of blue and
yellow economic zone, the highway distance between
two cities is shorter than the national road distance, ex-
cept Weifang-Binzhou and Weifang-Dezhou. The condi-
tions and the highest speed limit of highway are superior
to the national road, so it can largely save transportation
time when choosing highway. The highway between
Weifang and Dezhou is equivalent to going around the
two edges of the rectangle of which diagonal is Weifang
to Dezhou, so the distance is longer than the national
road. Therefore, we suggest establishing transverse con-
nection between G3 Jingtai highway and G25 Changshen
highway. So it can not only shorten the distance from
Dezhou to Weifang, but also benefit the three cities
(Binzhou, Jinan and Dezhou).
Table 4. The distance contrast between mainly contrast
group cities of blue yellow zone.
City-City Highway
distance National road
Weifang-Dongying 106 km 127 km
Dongying-Dezhou 219 km 254 km
Dezhou-Weifang 233 km 179 km
Binzhou-Weifang 180 km 134 km
Rizhao-Qingdao 134 km 188 km
Qingdao-Weifang 135 km 179 km
5. The Conclusion and Prospect
This article studies on logistics routing optimization by
applying the demand of the regional economic develop-
ment as the starting point, using spatial interactio n theory,
building a method of a regional logistics link optimiza-
tion based on the gravity model, and taking blue and yel-
low zones as the background to illustrate the rationality
and feasibility of this method. Supporting the economic
development is only one of the goals of the regional lo-
gistics development. As an independent economic activ-
ity, logistics is also one component of regional econo-
mies. Therefore the research on logistics route optimiza-
tion whose goal is the future logistics industry develop-
ment has certain theoretical value and practical signifi-
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[3] W.-L. Lan, S.-P. Tan and Y.-Q. Ma, “An Analysis of
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