Transportation Deployment Casebook/2014/Guangzhou Metro

Mode Description
Guangzhou Metro is an important rapid transit system in Guangzhou, which is the one of the biggest city in China. The metro system was started to build in 1993, and the first line was operated on Jun.28, 1997. By the end of 2013, Guangzhou Metro operates nine lines, which has the total mileage of 260.5 kilometers and the total station number of 164.

As one of the busiest metro systems around the world, Guangzhou Metro serves as a reliable rapid transit system for the residents in Guangzhou. The ridership has been increased along with the maturity of the Metro system, which helps to ease the traffic congestion on the surface road network effectively. Especially during Guangzhou Asian Games in 2010, the average ridership had reached approximately 7.8 million passengers per day, which breaks the national record of the highest passenger flow.

For transportation system, as we mentioned, Guangzhou Metro has high effectiveness to ease traffic congestion because of its absolute superiority on travel times. Accessibility of the road network has been improved considering the combination of Guangzhou Metro with other traffic modes, especially for key hubs, such as Guangzhou Rail Station, Tianhe Sports Center, and et.al. New lines or extension of existing lines are still built or planned to build in Guangzhou. The total mileage of Guangzhou Metro for long term planning will reach 751 kilometers, which will continue perfecting the metro system and promote the network accessibility.

For passengers, Guangzhou Metro could provide a higher level of transportation service, which improve travel environment from the safety, convenience and reliability aspects. Such advantages, which are highly considered by passengers, lead to the traffic modes converting from private cars to Metro systems. The reasonable and effective connections with surface transit systems, such as buses (including BRT system), taxis, and ferries, further promote the development of Guangzhou Metro, which strengthens its attractiveness for residents in Guangzhou.

The Previous Scene
For urban transportation, before the advent of Guangzhou Metro, available transit modes for passengers in Guangzhou contain buses, taxis, ferries and men-powered tricycles. Buses, as a major transit mode, played a vital role for the residents, especially for their daily commute. The rapid development of Guangzhou city causes the limitations of existing transportation modes considering the requirements from residents.

From the supply aspect, the capacity of traditional buses was the major limitation back then. Such a limitation was caused not only because of the design of vehicles, such as sizes, but because of the less effectiveness of the operation of the bus system. The less effectiveness showed from two parts. At first, many overlaps in bus routes resulted in lower coverage and unbalanced spatial distribution of the bus system. At second, incongruity connections between bus stations also weakened the operation of bus systems. Besides, the connections between the bus system and other transit systems also limited its efficiency.

From the demand aspects, increasing population and economics in Guangzhou has promoted the enhancement of transportation demand for transit systems. The ridership of the bus system had increased from 2990 in 1949 to 97959 in 1998, which is the year before the operation of first metro line in Guangzhou. And the limited capacity of buses lowered the service levels of the bus system because of the crowd and eventually could not satisfy the requirements of residents for transit systems. Besides, the increasing standard of living for residents causes higher expectation on transportation services, which reflected the dissatisfaction on transit systems back then.

Moreover, the car ownership has been increased from 2853 in 1969 to 221611 in 1997 along with the social and economic development in Guangzhou. The traffic congestions caused by such an increase required the improvement of transit system, which stimulate the invention of Guangzhou Metro.

Invention
Chen Yu, who was the governor of Guangdong Province, first proposed the construction of Metro system for Guangzhou. The immaturity of construction technology and the extreme hardship in economics made the project become impossible. The first lesson that Guangzhou Metro had learned was from the project of river-crossing tunnel in Zhujiang River, which treated as a construction experiment before the starts of Guangzhou Metro. Moreover, the birth and growth of Beijing Metro and Shanghai Metro brought some relative advanced technologies for subway construction for Guangzhou Metro, such as tunneling, rail and rolling stocks.

More technologies were applied into the Metro system in Guangzhou along with its rapid systematical development of Guangzhou Metro. For example, liner motor technology was used in Line 4, which was the first application in Metro system in China. The system has the advantages of strong grade ability, smaller turning radius and lower noises. Other technologies, such as integrated automation technology, moving block technology, intelligent driving technology, and et.al were also gathered together to realize the informationalized construction and operation of Guangzhou Metro.

Early Market Development
The birth of Guangzhou Metro is from 1991 (The year of the foundation of Guangzhou Metro Corporation) to 1999 (The year of operation of Line 1). Many challenges existed for the early market development of Guangzhou Metro. And the major one came from its competitors.

Bus transit, as the traditional transit system in Guangzhou, shared most ridership among transit modes. According to the statistical yearbook of Guangdong Province, the market-sharing percentile of buses for the transit system in 1999 was around 75%, while that of Guangzhou Metro was only about 0.03% Moreover, to satisfy the increasing transportation demand, more buses were applied into the bus system (531 more buses of 1998 than 1997), which brought more difficulties for market development of Guangzhou Metro in the early period. The number of taxies did has relative increase, which reflected the increasing expectation on traffic services. But the extent of such an increasing was not treated as competitors of Metro system. Ferry system had already reached its maturity, and its market-sharing started reducing, which could not limit the development of Guangzhou Metro.

Even private cars do not compete with Metro system directly, they did affect the early market of Guangzhou Metro. The economic development in China stimulates the rapid increase of private car ownership. From 1991 to 1998, the number of private cars increased from 96701 to 235727, which eased passengers desire to use public transit system for those who could afford a private car.

Although, in the early development period, Guangzhou Metro’s advantages on reliability did not show comprehensively since surface traffic conditions were not that bad in 1990s, its attractiveness on comfort, especially for longer trips, began to attract more passengers. And the growth of Guangzhou Metro started.

The Growth of Guangzhou Metro
The growth of Guangzhou Metro was started in 1999, and the rapid and comprehensive growth began in 2006. During this period, Guangzhou Metro has expressed a systematic extension in the transit system in Guangzhou. Mileage increase was not the only consideration for the development of Guangzhou Metro. The service coverage, the connections with key hubs and other transportation modes, the designs and locations of transfer stations were paid high attention to. Until today, the total number of transfer stations in Guangzhou Metro is 21, and the Metro system connects many key hubs such as the Railway station.

The market-sharing percentiles of Guangzhou Metro has been increased during the growth periods. In 2006, its market-sharing percentiles is 8%, which is much larger than that in 1998 (0.03%), while, in 2010, the percentiles reached 26.5%.

The Maturity of Guangzhou Metro
There is no specific definition about the beginning of the maturity of Guangzhou Metro. From the data of The Statistical Yearbook of Guangdong Province, we may treat the year of 2011 as the start of its maturity since the increasing ratio of ridership started to reduce in 2011. At that time, Guangzhou Metro has a relative perfect network to serve passengers with higher service level. Moreover, for the long term planning of Guangzhou Metro, the system will be further improved to be a major transit system in Guangzhou. However, new challenges created in this period, and a major one comes from the competition of Guangzhou Bus Rapid Transit System.

Guangzhou BRT system started to build in 2008 and to operate in 2010. It contains 51 BRT routes with the total length of 22.9 km. It adopted the direct link mode for the BRT system, which avoid the forced transfer in a closed system. The passenger volume in peak hours could reach 26.9 thousand passengers per hour, which is the second largest volume for BRT system around the world. The advantages of BRT system on flexibility and motility attracts more passengers after its operation. Moreover, the BRT system could also guarantee the reliability of its travel time. Hence, the development of Guangzhou BRT system is a competitive system for Guangzhou Metro.

Relative Policies
The birth of Guangzhou Metro was along with the national policy that the government encourages the development of mass transit system and the restriction of the usage of private cars. Local government also had a positive attitude to the construction of Metro system in Guangzhou. Hence, the priority of transportation was first proposed during this period, and the located government infused capital from France and German successively for the construction of Guangzhou Metro.

For the growth of Guangzhou Metro, many specific policies were proposed for a more efficient operation and management of Guangzhou Metro. Fare policy is a major part here. The fares of Guangzhou Metro are a segmented pricing based on different blocks. Many different tickets types are included in its fare policies, such as single journey tickets and day pass. Concessionary fares are also set for elderly and students. But many changes on tickets policy, such as the cancel of month pass and the changes of the fares discount, have negative effects on passengers. Safety is another important part for Guangzhou Metro. To guarantee the order of metro system, ‘the Regulation of Metro System of Guangzhou City’ and ‘Rules of ride in Guangzhou Metro’ have been proposed.

While some policies also cause negative influences on Guangzhou Metro, such as the construction of the BRT system, which was first proposed to enhance and complement the Metro system. However, the government still has the policies to promote the further development of the Metro system. So in the long term planning of Guangzhou Metro, until 2020, Guangzhou Metro will have the total lines of 15 and the total mileage of 550 km.

Quantitative Analysis
The annual ridership and mileage data are collected from the Statistical Yearbook of Guangzhou to analyze the life cycle of Guangzhou Metro, The ridership data is from 1998 to 2012 while the mileage data is from 1999 to 2012 because of the data missing. The collected data are showed in table 1.



A three-parameter logistic function was used to estimate the life cycle of Guangzhou Metro, which could be expressed as

S(t)=K/1+EXP(-b*(t-t0))                         (1)

Where K is the saturation status level, b is the coefficient of independent variable x in the linear regression model, which would be explained later. t is the time, which is the years here and t0 is the inflection time.

For the linear regression model that we used to estimate K, b and t0, we set that

Y=bX+c                       (2)

Y=LN(Ridership or Mileage/(K-Ridership or Mileage))    (3)

X=Years               (4)

Analysis of Ridership
Different values of K were tested at first to find the best estimated results for K, and we used R-Square and Adjusted R-Square results to compare the value of K. The comparison results were showed in Table 2.

From Table 2, it is clearly showed that regression has the best results when K value is set as 200000 since it has the highest R-square and Adjusted R-square. Hence, for the further estimation of ridership, we set the value of K is 200000. And the regression result of Y on X could be showed in Table 3.



The coefficient of X, which is the b in equation 1, and the intercept could be got from the regression model. Since t0 stands for the inflection time, which is the year that ridership equals to half of the saturation status (K Value), t0 could also be estimated based on the regression results.

t0=intercept/-b=2008.71 (5)

As all the unknown parameters, such as K, b and to, have been estimated, based on equation 1, we could estimate and predict the development trends of ridership in Guangzhou Metro and get a S-Curve showed in Figure 1.



From Figure 1, it is showed that the S-Curve of Ridership that we estimated fit the original data really well. The estimated ridership reflects the life cycle of Metro system in Guangzhou. After a rapid growth, the saturation status of Guangzhou Metro will be reached at the year around 2020.

Obvious gap exists between real ridership and estimated ridership, and it appears from 2006 to 2009, during which real ridership has a relative lower increasing ratio than the estimated one. The major reason for such a condition is that the construction of Metro system lowered its speed and the mileage increase ratio shows that. Since ridership of Guangzhou Metro is directly based on its coverage, a lower increasing speed of mileage companied with a lower increasing speed of ridership. Besides, the ticket policy changed from section-based segmented pricing into mileage-based one at the end of 2006, which could be an auxiliary reason for the appearance of the gap.

Analysis of Mileage
Similar to the analysis of ridership, for analyzing the mileage development of Guangzhou Metro, we, at first, need to estimate the best K value for mileage data of this Metro system. According to the development trend of mileage of Guangzhou Metro, we tested K values from 300km to 8000km. The R-Square and Adjusted R-Square results of regressions of mileage on years based on different K values shows in Table 4.



From Table 2, the highest R-square and Adjusted R-square appears when the K value is set as 2000km. Based on equation 3, the specific regression result of Y on X, in which K is set as 2000km, could be showed in Table 3.



The coefficient of this regression model is 0.2457, and the intercept is -496.21. According to the equation 5, t0 could be calculated as

t0=intercept/-b=2019.33 (6)

Then the development trends of Mileage in Guangzhou Metro could be estimated and predicted, and the S-Curve of the results was showed in Figure 2.



Since the K value that we estimated is much larger than the maximum mileage in the data of the last year and the t0 was in 2019, so most parts of this S-Curve are based on the prediction. The saturation status of Guangzhou Metro in mileage will be reached at the year 2040, which fit the long term planning of Guangzhou Metro. But the K value we adopted here is much larger than the planned mileage in 2040, which is 909km.

Gaps between real mileage and estimated mileage also exist. One reasonable explanation is that the construction period of Metro lines lasts longer, so the real mileage changes could not be as smooth as the estimated one. Besides, many problems arise along with the rapid development of Guangzhou Metro, such as the refurbishment of stations and the land subsidence in Metro system. Guangzhou Metro Corporation has to solve these problems during the construction periods, which limited the development speed.

Summary
From the quantitative analysis of both ridership and mileage, there are some conflicts between the development trends of ridership and mileage. At first, the S-Curve of ridership shows that Guangzhou Metro has been into the maturity phase, which the S-Curve of mileage means that Guangzhou Metro is still at the beginning of its growth phase, which could not meet with the current condition of Guangzhou Metro. At second, the time reached the saturation status was totally different between ridership and mileage. For ridership, the saturation status will be reached at 2020, which is the year to realize the objective of medium term planning for Guangzhou Metro. For mileage, 2040 is the year to realize the long term planning objective. These conflicts could reflect the unbalance of the development in Guangzhou Metro. The government and the Guangzhou Metro Corporation may need to pay attention to this problem.