*Article* **Comprehensive Sustainability Evaluation of High-Speed Railway (HSR) Construction Projects Based on Unascertained Measure and Analytic Hierarchy Process**

#### **Yongzhi Chang, Yang Yang and Suocheng Dong \***

Institute of Geographic Sciences and Natural Resources Research, The Chinese Academy of Sciences, Beijing 100101, China; changyz@igsnrr.ac.cn (Y.C.); yangy.15b@igsnrr.ac.cn (Y.Y.)

**\*** Correspondence: dongsc@igsnrr.ac.cn; Tel.: +86-10-6488-9430

Received: 4 January 2018; Accepted: 26 January 2018; Published: 5 February 2018

**Abstract:** This paper aims to evaluate the sustainability of high-speed railway (HSR) construction projects in a comprehensive manner. To this end, the author established an index system, involving 4 primary indices, 9 secondary indices, and 32 tertiary indices. The analytic hierarchy process (AHP) and the unascertained measure were introduced to calculate the weights of these indices. Then, the index system was applied to evaluate the sustainability of the China's Harbin-Dalian Passenger Dedicated Line (PDL). The results show that the Harbin-Dalian PDL project achieved good results in terms of process, economic benefit, impact, and sustainability, and will bring long-term benefits in the fields of tourism, economy, and transport capacity, as well as many other fields. In spite of its good overall sustainability, the project needs to further increase its economic benefits and reduce its negative environmental impact. For this purpose, it is necessary to adopt the managemen<sup>t</sup> mode of "separation between network and transportation" and apply noise prevention measures like noise barriers, tunnels, and overhead viaducts. This research lays a solid basis for the sustainability evaluation of HSR construction projects, and simplifies the modelling process for designers of HSR.

**Keywords:** high-speed railway (HSR); sustainable development; unascertained measure; analytic hierarchy process (AHP); Harbin-Dalian Passenger Dedicated Line (PDL)

## **1. History of HSR**

High-speed railway (HSR) is considered to be one of the most important breakthroughs in passenger transport technology made in the 20th century. Being a safe, rapid, reliable, comfortable, and convenient mode of transport, HSR has injected new vitality into the existing railway transport system and became a symbol of modern society [1–6].

Opened in 1964, the Tokaid ¯ o Shinkansen marked the dawn of the high-speed era, kicking off half ¯ a century of high-speed construction and research. At the sight of Japan's success, developed countries quickly followed suit.

The most famous project is the *Train à Grande Vitesse* (TGV) in France. TGV Sud-Est, the first line of the project, was funded by the French governmen<sup>t</sup> in 1976, and opened to the public between Paris and Lyon on 27 September 1981. The trains operate on the line at a maximum speed of 270 km·h−<sup>1</sup> [7]. The commercial success of the first TGV led to an expansion of the network to different parts of France. The statistics of the International Union of Railways (UIC) show that the TGV had 2142 km of HSR in operation, 634 km under construction, and 1786 km being planned by the end of April 2017 [8].

The success of the TGV motivated other European countries to construct HSR within and across their borders, forming a high-speed network across the continent. These countries include Germany (1988), Italy (1988), Spain (1992), Belgium (1997), the United Kingdom (2003), and the Netherlands (2009). After the turn of the century, the high-speed boom spread eastwards to Asia. Different forms of HSR were built in Korea (2004) and China (2008).

Over the past 50 years, the global HSR network has transported about 15 billion passengers, about twice the world population. According to UIC statistics, 34,000 km of HSR had entered service by the end of 2016 [9], an increase of 14.86% compared to 2015 (Figure 1); the mileage rocketed up to 37,300 km by the end of April 2017, with another 15,900 km under construction [10]. Asia and Europe accounted for 98.07% of all HSR in service and under construction around the world (Figure 2).

**Figure 1.** Global total mileage of HSR till 2016.

**Figure 2.** The global percentage of in-service under construction mileage of HSR in Asia, Europe, North America, and Africa in April 2017.

HSR construction is in full swing across China. In 2008, the Beijing–Tianjin Intercity Railway became the first line in the country to accommodate trains travelling at maximum speeds above 300 km. A boom of HSR construction ensued. By the end of April 2017, China had built the world's longest high-speed network, consisting of 84 high-speed lines (segments). In total, there were 23,900 km of route in service, and 10,700 km under construction. The two mileages take up 57.87% and 97.72% of the global total, respectively [8].

With only a couple of years, China has caught up with the first movers in HSR and become the focal point of HSR development. The HSR has been recognized as a first product of Chinese manufacturing [11–15]. Guided by the "going global" strategy, China is actively building HSR linking up the countries along the overland and the maritime silk roads. Once completed, these railways will

boost the development of infrastructure and regional economy in all the countries radiated by the "the Belt and Road" [16].

## **2. Requirements on HSR**

HSR is a major booster of socioeconomic development and the cornerstone of many industries. However, the environmental impact of HSR should never be overlooked. Despite being more environmental friendly than traditional transport modes (e.g., highway), HSR has led to some environmental and resource problems due to the largescale construction and leapfrogging development. To solve the problems, the planners, constructors, and operators of HSR must strike a balance between railway, population, economy, environment, and resources, so that the HSR develops in a sustainable manner.

Sustainable development is the ultimate goal of transportation. The key to sustainable development of transportation industry lies in its coordination with society, economy, environment, and resources [17–22]. In this research, the sustainable development of HSR is investigated from both internal and external perspectives that are required to satisfy the operating framework in Figure 3 [23,24].

**Figure 3.** Operating framework for the sustainable development of HSR [23,24].

The sustainable development of HSR should meet three conditions. First, HSR must adapt to the socioeconomic situation. The development of HSR both depends on social and economic factors and promotes socioeconomic development. Second, HSR development must be coordinated internally. The internal elements include infrastructure, transport equipment, scheduling, service provision, and software-hardware integration. Third, HSR should pursue green development and ecological harmony. For this purpose, the land and non-renewable resources ought to be utilized rationally, and environmental pollution and traffic accidents must be avoided.

Facing the above requirements, it is urgen<sup>t</sup> to rationalize the planning and construction of HSR projects and realize the sustainable development of the HSR network. One of the viable options is to evaluate every aspect of HSR development and weigh the pros and cons of existing and impending projects. The comprehensive evaluation is critical to the healthy development of HSR [25].

## **3. Literature Review**

The sustainability evaluation of HSR construction projects started late at home and abroad. The existing research emphasizes theoretical analysis over empirical evidence and lacks sufficient evaluation contents, systematic indices and feasible methods. The rationality, normality, and feasibility of the evaluation are ye<sup>t</sup> to be improved.

The current evaluation methods include analytical hierarchy process (AHP) [26–28], neural network [29], fuzzy mathematics [27,30,31], multi-criteria decision analysis [32,33], fault tree analysis [34], visco-elastic model [35], transfer function [36], finite element [37], etc. Most of these approaches tackle a single aspect of sustainable development. Only a few support comprehensive evaluation, namely, neural network and fuzzy mathematics. The problem is these few methods perform poorly in index selection and weight determination.

The sustainability evaluation of HSR construction projects involves much uncertainty and covertness. In particular, many attributes are uncertain in the decision-making process. Hence, the evaluation should cover both quantitative and qualitative indices. The unascertained measure theory is an ideal way to deal with uncertain information and achieve a comprehensive evaluation. Nevertheless, it is difficult to determine the weight of a complex index system that relies solely on the unascertained measure theory.

To overcome the defect, it is necessary to introduce the AHP to the evaluation process. Taking the object as a system, the AHP makes decisions through decomposition, comparative judgment, and totalization. By this method, the factors of a complex system are divided into interconnected, orderly layers; the importance of each layer relative to the other layer is quantified, and the weight of each layer is determined mathematically. In this way, the decision is made according to objective reality.

In view of the above facts and the features of HSR construction projects, this paper establishes a complete index system for sustainability evaluation. The system has such four primary indices as process, economic benefits, effect, and sustainability. Then, the unascertained measure was adopted to create the sustainability evaluation model for HSR construction projects. Then, the model was applied to the sustainability evaluation of the Harbin-Dalian Passenger Dedicated Line (PDL). This research lays a solid basis for sustainability evaluation of HSR construction projects and simplifies the modelling process for designers of HSR.

#### **4. Establishment of Evaluation Index System**

The index system is essential to the accuracy and reliability of the sustainability evaluation. Based on the literature review, the author decided to carry out a questionnaire survey before setting up the index system. The questionnaire was prepared after interviewing 30 HSR experts working in national and local governments, construction companies, design institutions, railway managemen<sup>t</sup> departments, advisory bodies, and research institutes. Prior to the survey, the preliminary questionnaire was validated with selected samples and optimized into a formal questionnaire. After the survey, a field investigation was carried out to extract common factors through the factor analysis.

Considering the correlation between the factors, the author constructed the index system for the sustainability evaluation of HSR construction projects. Four layers of indices were introduced, namely the target layer (main index), criteria layer (primary indices), sub-criteria layer (secondary indices), and solution layer (tertiary indices). The solution layer consists of 32 indices that explain the factors on the sub-criteria layer (Table 1). The goal is to describe the elements in the tertiary indices and obtain the values of the evaluation indices in light of the actual situation of the object. As mentioned above, the index system has such four primary indices as process, economic benefits, effect, and sustainability.


**Table 1.** The evaluation index system for the sustainable development of HSR construction project [23,27].

The process evaluation index covers pre-bid decision-making, construction, and operation. These indices evaluate the actual project situation in the early stage, including work performance, construction quality, and operation efficiency. Based on the evaluation results, one can learn from the successes and failures, enhance the project quality, and elevate the managemen<sup>t</sup> level.

The economic benefits include financial benefit and national economy. As its name suggests, the former index measures the financial benefit of the project. To evaluate the index, the income and expenses were acquired from the project's financial statements, and the implementation of the national tax system was taken as a reference. According to *Railway construction project economic evaluation methods and parameters (3nd edition)* (Ministry of Housing and Urban-Rural Development of the PRC, National Development and Reform Commission of the PRC, Ministry of Railways of the PRC, 2012) [38] and literature [39], the financial benefit of the project was further split into profitability and debt paying ability. The latter index, national economy, is fundamental to the sustainable development of HSR construction projects. The index reflects the net contribution of project to the national economy, and discloses the economic effect of project cost and investment.

The social effect evaluation exists in the forms of social effect and environmental effect. From the sociological angle, this paper explores the social effect from four dimensions (Table 2). The environmental effect refers to the chemicals, wastes, noises, and electromagnetic radiations

released during project construction and operations in the natural environment (e.g., water, air and soil). The evaluation results make it possible to minimize the adverse effects on the life of local residents and ecological system.


**Table 2.** The index system of social effect evaluation.

The sustainability evaluation is prospective in nature. For sustainable development, the relevant internal and external factors are evaluated in scientific means, along with the realization and influence of the project. In light of the evaluation results, one can give advice on how to promote sustainable development from the perspectives of technology, economy, society, and environment.

## **5. Unascertained Measure Theory**

Uncertainty exists extensively in objective and subjective worlds; the uncertain information includes two basic meanings: randomness and ambiguity [40,41]. In 1836, Mill [42] proposed firstly the concept of "uncertainty". Stochastic problem was first proposed by the Soviet mathematician Kolmogorov in 1933, and he established probability theory and the axiomatic method [43]. In 1965, the concept of fuzzy information and fuzzy set theory was created by American scholar Zaden, who developed the study field of uncertainty [44]. Chinese scholar Deng founded the grey system theory in 1982 [45]. In 1991, Wang built a universal grey set on the basis of grey system theory; it involved a lot uncertain information [46]. Academician Wang, a famous Chinese scientist, put forward various types of information concepts, namely, unascertained information in 1990, which are different from random information and fuzzy information [47]. At present, there is a unified understanding of fuzzy information, random information, and gray information in uncertain information, but there is no uniform definition for unascertained information. However, theorists basically agree that unascertained information is the subjective uncertainty of decision makers because they lack information to determine the real state and quantity of the object. This creates subjective and cognitive uncertainty for decision makers due to the lack of objective information. It is fundamentally different from concepts like randomness (which only deals with what happens in the future), fuzziness (which reflects the nature of a certain object that does not have a clear definition or an evaluation target), and grayness.

Thanks to the concerted efforts of scholars like Álvaro [48] and Wu [49], so far, a systematic theory and method have been developed for unascertained information, which was first proposed by Academician Wang [47].

#### **6. Establishment of Unascertained Measure Model**

Set x1, x2, ··· , xn as evaluation objects of news sensitivity, set universe U = {x1, x2, ··· , xn}. The evaluation xi ∈ U (i = 1, 2, ··· , n) has m first indices I1,I2, ··· ,Im and I = {I1, I2, ··· , Im}. For Ii ∈ I has k secondary evaluation indices Ii1,Ii2, ··· ,Iik, and Ii = {Ii1,Ii2, ··· ,Iik}. Therefore, xij can be expressed as k dimensional vector xij = xij1, xij2, ··· , xijk, xijr means the value of the secondary indices of Ij, which is xi's first index. Each xijr has p evaluate grades c1, c2, ··· , cp, the evaluation space is C = {c1, c2, ··· , cp} [40,41].
