Assessing urban sustainability in Saudi Arabia: an empirical evidence from Al-Medina Al-Munawwarah

This study aims to assess the progress towards Sustainable Development Goal 11 (SDG 11) in Al-Madinah Al-Munawwarah, Saudi Arabia. The study also examines challenges that encounter SDG 11. To this end, six targets consisting of 40 indicators of SDG 11 have been adopted, relying on literature, international and national technical reports, and the personal perspectives of twelve experts. Overall progress towards SDG 11 has shown significant improvement considerably, with a middle level, particularly after Saudi Vision 2030 was approved. The findings show that three targets including affordable housing, sustainable transportation, and sustainable urbanization, have achieved average progress, and two targets, including air quality, and waste management, and access to green areas have been demonstrated low progress, as well as a single target, which is the preservation and protection of natural and cultural heritage, which has achieved optimal progress. The results highlight several challenges that hinder progress towards SDG 11, but the level of these challenges varies from one target to another target, ranging from moderate to major challenges. These challenges should be considered in continuing urban strategies and could be reduced by establishing resource-saving and innovative community urban renewal programs.


Introduction
Extant literature has defined sustainability in various ways, but many interpretations of this term concentrate on human needs and values, with an emphasis on the future [1].Increasing concern over time has initiated an entirely new terminology for 'sustainability science' which focuses on facing existing and future challenges and solving problems [2,3].It also aims to establish a balance between human activities and the environment [4].Today, one of the most important challenges for sustainability science is worldwide rapid urbanization growth [5,6].According to the World Urbanization Prospects Report, published by the United Nations in 2018, about 55% of the world's population live in cities; by the year 2050, 68% of the world's population is anticipated to be living in urban areas [7].The outcomes of this rapid urbanization include many challenges, such as environmental threats, increasing burdens on services and infrastructure, traffic congestion, increased consumption of energy and water; and disappearing agricultural land.
Therefore, sustainability has become a key objective of international organizations and individual scholars over recent decades.For instance, the European Commission developed the Sustainable Cities Project in 1991 and published the European Sustainable Cities Report in 1996.Such initiatives enable local authorities to manage and guide cities in a sustainable manner.The urban sustainability model integrates policies holistically over different levels, to assess the relationship between people, the environment, and socio-economic activities, in order to meet resident needs both in the present and for future generations [8].
The United Nations developed the Sustainable Development Goals (SDGs) to achieve a better sustainable future for all.The 17 Goals, which should be achieved by 2030, address many global challenges such as poverty, climate change, natural resources, and environmental challenges.These goals are broadly considered as a powerful political instrument that address the social, economic and environmental pillars [9].Among these goals, SDG 11 focuses on 'making cities and human settlements inclusive, safe, resilient and sustainable', linking the quality of life in cities to manage available resources socially, economically, and environmentally.This study targets SDG 11, where urbanization increases the burden on the environment and accelerates demand for transportation, housing, infrastructure, land, and other basic services, particularly in developing countries [10].
Existing research on SDG 11 has attempted to reach practical solutions for relevant policy issues, with most academic studies arguing that improvements to institutional capacity, policy instruments, and efficient resource use can be achieved efficiently by assessing various SDGs, including SDG 11.Despite the importance of SDGs, (with SDG 11being particularly relevant in all world cities), research regarding this is less developed in Middle Eastern countries.Both the Scopus and Web of Science databases indicate that most research on urban sustainability focuses on the USA, China, and Western Europe, and that research on Middle Eastern countries is lacking.However, authors such as Andriamahefazafy et al [11]; Allen et al [12]; Kawakubo et al [13]; Alawneh et al [14]; Ugiawan et al [15], have confirmed the need for further research of SDGs in the context of Middle East countries.Therefore, this study attempts to remedy this research gap by focusing on Saudi Arabia, as it is the largest country in the Middle East region.Research on SDGs in the context of Saudi Arabia is lacking.For example, the Scopus database shows that the number of peer reviewed articles is 145 in terms of sustainable development, out of them 17 papers on SDGs.Thus, assessing SDG 11 in Saudi Arabia can extend knowledge and provide useful insights into the urban research.The study fundamentally aims to assess the progress of SDG 11 in Saudi Arabia, using Al-Madinah as a case study, while addressing the following research questions: (1) How can the progress of SDG 11 be evaluated?(2) What are the indicators that measure the progress of SDG 11? (3) What are the gaps that encounter the progress of SDG 11? (4) What are the key suggestions to improve the progress of SDG 11?The main value of this assessment is its contribution to exploring the frontiers of development trends in urban sustainability, thus enabling researchers, decision makers, and planners to better understand urban sustainability in context of SDG 11, as well as providing original, useful insights and perspectives for relevant policy issues in Middle Eastern countries as a wide range of indicators and subindicator items have been assessed.
The remainder of the study is structured as follows: section 2 focuses on the literature review, which provides a brief overview of prior studies related to the subject matter.Section 3 deals with data and methodology adopted in the study.Section 4 presents empirical findings and discussion based on the outcomes of the analysis, while section 5 focuses on the concluding remarks and policy implication.

Literature review
Academic literature defines urban sustainability in a variety of contexts.Verma and Raghubanshi [16] describe urban sustainability as a cross-cutting area that influences the environment, society, and the economy.Zhao [17] considers a sustainable city to be one that enables its inhabitants access to sustainable welfare while preserving the ecosystem.Mega and Pedersen [18] believe a sustainable city is one that achieves socio-economic and environmental balance through community engagement, whereas Wu [19] considers urban sustainability to be an instrument which enhances, conserves and facilitates a virtual linkage between the ecosystem and human well-being, by channels of coordination between different urban activities.Iovino [20] defines a sustainable city as one that achieves long term socio-economic and environmental accomplishments, with preservation of resources.A common thread pervading all of these definitions is that long term improvement of cities requires reducing both the consumption of resources and environmental risk, as well as enhancing efficient resource use to improve overall quality of life for the existing population and future generations.
Several technical reports and studies based on assessing SDGs have been undertaken, which have attempted to assess the progress of urban sustainability.Shen et al [21] used an International Urban Sustainability Indicators List (IUSIL), to investigate nine cities including Melbourne, Hong Kong, Iskandar, Barcelona, Mexico City, Taipei, Singapore, Chandigarh, and Pune.The study provided important insights into engines and objectives of each practice and showing under what circumstances different practices adopted their indicators.The comparison conducted by this study has taken into account social, economic, environmental, and governance pillars of sustainability.The study illustrated how comparative basis can create knowledge sharing between various practices, which can be used to adopt indicators of urban sustainability.The study concluded that the adoption of indicators across global cities should be based on a holistic understanding of socioeconomic and environmental contexts of each city.Yigitcanlar and Dur [22] have developed a comparative model, 'Sustainable Infrastructure, Land-use, Environment and Transport (SILENT)' which measures various sustainability indicators of cities.It provides a comprehensive perspective of the sustainability indicators used by policymakers and academics in order to measure progress, plan for the future and face current sustainability challenges.Lee and Huang [23] propose 51 indicators which can be used to evaluate public policies; their study aims to create sustainable development in the context of Taipei.They consider four dimensions; the economy, society, environment, and performance of urban institutions, highlighting the way in which balance can be reached between all four areas.Panda et al [24] have developed an Urban Social Sustainability Index, which considers several areas of sustainability based on expert opinions.They have conducted a factor analysis, which specifies scores, and provides a thematic index using linear regression.This study is similar to the methodology used by Salvati and Carlucci [25].Luan et al [26] have developed a holistic index using a sensitivity analysis with 18 indicators, which has determined the relative importance of sustainable development indicators.
A number of United Nations organizations have developed a holistic and common agenda for following up accomplishments of sustainable urban development worldwide, such as Ecological Footprint (EF), Green City Index (GCI), City Development Index (CDI), Environmental Performance Index (EPI), Genuine Progress Indicator (GPI), Genuine Savings (GS), Human Development Index (HDI), Happy Planet Index (HPI), Wellbeing Index (WI), and Sustainable Society Index (SSI).The scope of urban sustainability indicators (USIs) in social, economic, and environmental dimensions is significant both theoretically and practically, as it allows follow ups and comparisons of urban sustainability between world cities.The use of comparable indicators enables cities to share best practice to create sustainable cities.However, despite the help these indices provide in terms of assessing progress towards urban sustainability, their application across cities is difficult, due to the differentiation of the concept of sustainability from one city to another.Hence, assessment of urban sustainability should be conducted in a systematic framework which includes socioeconomic and environmental dimension at the local level.The SDGs aim to enable policymakers to understand why and how to design, execute, and tackle urban policies universally, and thus they contribute to localizing sustainability in cities and creating frameworks for sustainability evaluation.
A body of literature has reported the execution of the SDGs at both international and national levels [27].Records of execution contain policy, strategy, frameworks, technical reports, and academic studies.Only 66 out of 193 countries had begun executing the SDGs in the early stages of the UN's suggested execution span and have recorded their progress by the Voluntary National Reviews [28].According to Allen et al [12] the progress towards achieving the SDGs is still limited, with linking urban activities to the SDGs [29,30], raising the concerns (i.e.low prioritization and lack of resources to implement goals) about the mechanism of the execution of SDGs [31].In this context, Sachs et al [10] illustrate that the progress towards SDGs in Saudi Arabia is associated with several challenges that need to be addressed.
A key engine for barriers in executing the SDGs is a lack of systematic reviews, with a limited assessments and revisions comprehensively [32,33].Amos and Lydgate [34] discuss that the deviations associated with execution may be related to difficulty in conveying the framework into reality.Thus, an evaluation a single SDG such as SDG 11 by considering social, economic, and environmental pillars of sustainability will offer a comprehensive vision to execute SDGs successfully.
Addressing SDG 11, among other goals, is needed in order to reach practical solutions to current challenges and enhance progress towards sustainable development and quality of life.SDG 11 aims to 'make cities and human settlements inclusive, safe, resilient and sustainable'.It consists of 9 indicators; affordable housing, public transport, sustainable urbanization and participation, natural and cultural heritage, managing disasters, air quality and waste management, access to green areas and public spaces, linking between urban, peri-urban and rural areas, and integrated policies towards inclusion and resource efficiency [35].Financial and technical support is available for developing countries, to facilitate sustainable development.All of these indicators are identified with the three key areas of environment, economy and society, and are based on the idea that an integrated system improves residents' lives economically, socially, and environmentally.The economic dimension considers urban economics and real estate activities; it must also be noted here that creating strong urban economic development is often associated with challenges, such as overuse of resources and environmental problems.Industrial transition and city logistics have become a major contributor to national economics, but at the same time, a source of environmental problems [36].Hence, several studies discuss the side-effects of economics in the context of SDGs, such as the effectiveness of green productivity development [37,38] and economic growth momentum [39].Existing urban research studies discuss ecological and natural resources in an urban growth context, highlighting the benefits of urban ecological-economic systems [40], biodiversity [41], urban green spaces [42], role of intelligence in sustainable development [43], environmental urban challenges [44], and energy and climate sustainability [45].These studies aim to create a balance between the use of resources and preservation of the environment.Participation, governance, and equity are key norms of social sustainability in SDG 11 [46].Basic facilities such as infrastructure, communication networks, and amenities, like affordable housing and conservation of cultural and natural heritage, are important elements in terms of improving social sustainability [47].According to Yigitcanlar and Dur [22, p.423-424], indicators such as demand for housing, industrial production, efficient energy use, pollution rates, conservation of natural heritage, access to infrastructure and facilities, access to transport, changes in population growth components, social cohesion, public security, justice and equity, poverty, unemployment rate, quality of life, community engagement, health and safety, literacy and education are among the fundamental indicators often used to assess urban sustainability at the local level.
Affordable housing is one of the most important targets of SDG 11, which seeks to achieve sustainable development.It consists of several indicators, including ratio of people living in informal areas, housing price to income, residential plot price to income, ratio of electricity coverage, households supplied with clean and potable water, ratio of households with access to improved sanitation, the proportion of area per individual in the family, ratio of durable, structurally sound houses, homeownership ratio with legal documentation, homeownership ratio, and mortgage as a percentage of income [27,43,[48][49][50][51][52].These indicators work together to achieve affordable housing in the social, economic, and environmental pillars of sustainability.Socially, affordable housing, as a basic need, can be achieved by providing mortgage facilities to increase homeownership.Mortgage facilities have the ability to reduce the ratio of people living in informal settlements.An increase in homeownership rates creates social stability, as people seek to obtain homeownership, not housing itself, because homeownership is considered a source of security and is socially valued [4].Economically, housing and residential plot prices play crucial roles in enabling people to obtain affordable housing [53].When housing prices rise, reduction in homeownership becomes the norm, and people tend to move out affordable housing due to market pressures [53].Environmentally, services such as electricity, clean and potable water, improved sanitation, area per individual of house, and durable and structurally sound houses, enable people to live, work, and communicate.The lack of these services declines the urban built environment over time [54].
Sustainable transportation is another target of SDG 11 that aims to improve accessibility and enhance economic activities.This target includes several indicators, such as the ratio of household's expenditure on transportation, the rate of car ownership, average time drive from CBD to any area of the city (in minutes), the overall amount of road network within the urban boundary, and the amount of road surface per capita [48,[55][56][57].Sustainable economic development requires reducing the household's expenditure on transportation, to between 10% and 20% of household income [44], achieved through an effective public transportation system [55].The effectiveness of public transportation is dependent on the ability of city planning to interconnect lines that depict the arrangement of streets or roads of the overall amount of road network within the urban boundary [58].The efficiency of road network impacts the time spent on travelling; the lower the average travel time, the lower expenditure on transportation [59].Environmentally, reducing travel time decreases non-renewable energy consumption which leads to environmental degradation, particularly transportation is still mainly dependent on fossil fuels sources in developing countries [55].
Another target of SDG 11 is sustainable urbanization, which deals with multiple indicators linking urban transformations to sustainability.These indicators include population number, population growth rate, the annual number of visitors (in millions), urban growth rate, urban density, land consumption rate, built up area, total urban area, uncontrolled areas of overall urban footprint, and people living in uncontrolled areas with an overall urban footprint [35,48,60,61].An increase in population growth raises demand for urban space and resources consumption.Additionally, an increase in the annual number of visitors to a city for tourism purposes also contributes to increasing pressure on urban space, construction, and services.Consequently, the increase in population, space, and construction leads to an increase in urban growth rate [4].Urban growth does not operate in a vacuum; rather it is accompanied by spatial and temporal scales [4].Spatial scales refer to three indicators, including: (1) total urban area which refers to area of towns and neighborhoods and other uses within urban boundaries approved by urban authorities [48,51], (2) built-up area which means all areas occupied by buildings [48], and (3) urban density defined as the number of population within specific city divided by the total area of the city [48,51].Temporal scales focus on several indicators, including: (1) change in urban expansion over time, (2) land consumption rate which refers to the percentage change in urban land over a designated period, usually one year, expressed the initial land area occupied by the city at the beginning of that period [48,51].The final outcome of urban growth pattern could appear uncontrolled or controlled [4].An uncontrolled urban pattern refers to unorganized form for urban areas, such as informal areas where people build or obtain shelter without compliance with planning regulations or having legal homeownership [4].Generally, these areas are characterized by a lack of infrastructure and services, leading to environmental problems in the context of urban footprint.Hence, two indicators should be considered, including: (1) uncontrolled areas within the overall urban footprint, which means the proportion of uncontrolled areas compared to other land use types, and (2) people live in uncontrolled areas with an overall urban footprint, which indicates the proportion of the population who live in uncontrolled areas of the overall population live in an urban footprint [51].
Preserving and protecting natural and cultural heritage is one of the targets of SDG 11 that plays a vital role in enhancing sustainable development.The main principle of this target is to protect the natural and cultural heritage sites and environment by enhancing economic activities such as tourism and business [62].This indicator can be measured by two types of expenditure, including public and private [48].The total expenditure (public and private) is related to various factors, including the number of cultural and natural heritage sites, amount of financial investments in cultural and natural heritage, and the number of annual visitors [62].Hence, the total expenditure reflects the city's strength in protecting natural and cultural heritage.
Another target of SDG 11 is air quality, municipal and other waste management, and improved water.These elements are essential to achieve sustainability.Providing safe drinking water is associated with challenges, including high maintenance costs, ageing water infrastructure, and increased water consumption due to rapid population increase [63][64][65].The ability of cities to provide sufficient amount of safe water for citizens influenced by average amount of water for each individual in the city uses daily, expressed as a liter per capita per day [48,51].Moreover, sustainable cities require an effective system of waste management.The effectiveness of waste management is influenced by several indicators, including: (1) The proportion of houses served by regular waste collection [48,51], the higher the proportion, the higher the effectiveness. ( The ratio of recycled solid waste [48,51], which reflects the proportion of materials recycled or recovered from solid waste, calculated as the annual total waste recycled divided by the annual total waste generation [48,51]. (3) The daily rate of municipal solid waste which includes waste generated from households, commercial activities, public-private buildings, hospitals, small businesses, small businesses, road networks, and park and garden maintenance [23,48].
(4) The proportion of sanitary landfills/burials, which is concerned with the disposal of waste onto or into land, encompasses purposefully designed landfill sites and the temporary storage of waste for more than one year on permanent sites [48].
Finally, people and governments are interested in air quality.The focus on real-time monitoring for air pollution provides information for policymakers and contributes to improving the environment and citizens' quality of life.Air quality is assessed by the annual mean concentration of particulate matter of less than 2.5 microns in diameter (PM2.5)(μg/m 3 ) [48,51].This indicator refers to the average annual concentration of fine suspended particles with a diameter of less than 2.5 microns, a prevalent indicator used to assess air pollution levels [48,51].Regarding PM2.5, the daily concentrations should not surpass 25 μg/m 3 more than 18 times within a calendar year, and the annual mean concentrations are expected not to outstrip 10 μ μg/m 3 by the year 2030 [48,51].
Access to green areas and public spaces is another key target of SDG 11, aiming to increase the perceived value of public spaces and green areas by policymakers and citizens [66].This target can be assessed by multiple indicators, including: (1) Green coverage ratio of urban areas, which refers to open areas designated for parks, encompassing plant life, water features, and various natural environments [48,51].
(2) Green space area per person (M 2 ), which includes recreational areas that are provided by the public sector for residents and situated with no buildings, and people should have access to green areas without charge [48,51].
(3) Vacant land ratio which concerns land that can be developed but is not currently occupied [48,51].
(4) Ratio of agricultural land is to express the proportion of farmland within the city -compared to the city's total area [27].
(5) The overall ratio of developable land, which refers to the total area of land suitable for zoning and planning, and, consequently, suitable for connection with infrastructure and services.'[67].
Although the SDG 11 indicators are not applicable for every country [48], they are essential to understand current challenges and offer a foundation for assessing environmental, economic, and social changes.If decision-makers and researchers are informed about current socio-economic and environmental conditions, they can manage local strengths and weaknesses to successfully determine city priorities and achieve desired goals.Finally, the SDG 11 indicators contribute to creating a valid framework and offer practical insights into the assessment process of urban sustainability.
Current assessments indicate there is a need for further research regarding SDG tracking and institutional practice.Scholars, town planners and experts have all suggested a number of additional indicators which could be used to enhance the ability of local authorities to track progress for SDGs [48,68,69].Nonetheless, the suggested indicators can be used to measure the progress of SDGs at a global level [70,71].Thus, they contain several indicators that have not been applied for tracking progress at the local level [71].Indicators must be adapted, or alternative indicators predicted to follow up th71e performance of local authorities and the success of the SDGs at the city level [49,72].Although many sub-indicators have been proposed which could evaluate SDGs, an assessment approach for following up SDG 11 progress at the city level is limited [73,74].Hence, this current study could be used to enhance the performance of local authorities in their assessment.This paper assesses the progress of SDG 11 at the city level, taking into account localizing SDG indicators and introducing indicators that are in line with SDG 11.

Data and method
Extant research on assessing and tracking progress towards SDGs in Saudi Arabia is scarce [50,[75][76][77][78]. Al-Madinah is the fourth most populous city in Saudi Arabia, and hosts the highest number of visitors in the Islamic world.The holy city of Al-Madinah Al-Munawwarah is the administrative capital of the Al-Madinah Region, and is located in the northwest of Saudi Arabia.In 2022, among other Saudi cities including Riyadh, Mecca, and Jeddah, the city of Al-Madinah was classified as a smart city in the international Smart City Index developed by IMD [79].
Data Based on the available data, this study targets six areas of SDG 11, including affordable housing, public transportation, sustainable urbanization and participation, preserving and protecting the natural and cultural heritage, air quality and municipal and other waste management, and access to green and public spaces.A total of 40 sub-indicator items have been adopted according to academic literature (e.g.[11,13,15,22,27,33,35]), international technical indices and reports (e.g.SDG Indicator Metadata 2022, the World Cities Report 2022).It has been discussed that indicators of SDGs are positioned by the UN globally (see https://unstats.un.org/sdgs/ metadata/?Text=&Goal=11&Target) and the performance of these indicators can vary from one country to another [71,72], and from international level to local level [48,68].This study uses opinions of 12 technical experts, drawn from the Middle East and Saudi Arabia, who have deep knowledge and practical experience in the implementation of SDG 11 in order to judge the reliability of data sources and evaluate the values of indicator items.The experts were from different sectors, including the public sector, universities, and the UN.The experts specialize in the research fields of sustainable development, sustainable cities, and sustainable urban planning.
Hence, a scale consists of three levels including (1) optimal, (2) average, and (3) low was proposed by experts to judge the level of each indicator.Sharaf [67] used the same technique to assess the SDG 11 in the city of Amman, Jordan.Accordingly, the total summation of normalized values, which ranges from 1 being optimal and 3 as the lowest, gives us the overall level of progress towards SDG 11.Veckalne and Tambovceva [64] examined urban sustainability in Uzbekistan using the same technique.
Data normalization was defined by maximum and minimum values, where the values of each indicator varied.After computing each indicator's maximum and minimum limits, the following equations used the extreme value normalization.If the indicator value is positive, computation is applied using the first, third, fourth and fifth equations. - It should be noted that the available values for indicators are heterogeneous.For example, the low value of some indicators (such as air quality and emissions), means that the indicator is good.If the indicator value is negative, computation is applied using the second equation. - When the government establishes an optimal value for a specific indicator, such as the mortgage as a percentage of income, the calculation is conducted using the formulas outlined in equations (3), (4), and (5). - Where I i is the indicator value x opt is the indicator optimal value x i is the ideal value for moderate indicator x max are the upper limits for the indicator x min are the lower limits for the indicator.

Performance of SDG 11
Table 2 shows that the normalized values are accounted for 1.578, which is very close to 1.5.The result implies that Madinah is in the middle level of sustainability, ranging from 1 to 3, with 1 being the highest level of sustainability and 3 the lowest.With these findings, we aimed to assess SDG 11 that cover multiple targets and indicators including affordable housing, public transportation, sustainable urbanization and participation, preserving and protecting the natural and cultural heritage, air quality and municipal and other waste management, and access to green and public spaces.The findings indicate that there is a progress towards SDG 11, with several challenges.The findings imply that Saudi Arabia has taken great steps to incorporate SDG 11 in their local strategies yet action takes place by governance system that is still in the transformation phase towards change for better, affecting the implementation of SDG 11.The findings align with the assessment of SDGs conducted by Sachs et al [10] of world countries in 2023.The results of this assessment on Saudi Arabia reveal that SDG 11 is progressing with moderate challenges.The results also agree with the work provided by Allen et al [12] in which 40% of countries had completed their prioritization of SDG targets and indicators, compared to 30% of countries were in the phase of prioritization, suggesting the execution of SDGs is not limited.The findings are in line with empirical results provided by Veckalne and Tambovceva [80] in which urban sustainability in Uzbekistan has achieved a middle level, with a score 1.5 out of 3. The results agree with Sharaf [67] who assessed SDG 11 in the city of Amman, Jordan, concluding the level of performance is average.The results confirm the perspective of Shen et al [21] in which the practices of sustainable development can vary from one country to another country and thus the selection of assessment indicators should consider the differences between countries and should be based on a comprehensive understanding of social, economic, and environmental pillars of sustainability.For instance, Xu et al [27] found that the progress of SDG 11 in the Yangtze River Delta Urban Agglomeration is gradually with moderate challenges, but the practices of SDG 11 vary from the Yangtze River Delta Urban Agglomeration to Saudi context.In Saudi Arabia, the achievement of SDGs is based on local perspective of each city with existence fund, while the practices of Yangtze River Delta Urban Agglomeration to achieve SDGs are based on regional perspective and the degree of coordination between various urban agencies in different cities.
Based on the findings and values included in tables 1 and 2, we established table 3 in order to determine the level of progress and challenge towards targets of SDG 11.
The assessment result for the target of affordable housing reveals an average performance, indicating an existence of moderate challenges.Many sub-indicator items are semi-optimal, such as the ratio of the population living in informal settlements (1.3% in 2022), proportion of the housing price to income (5.5),proportion of residential plot price to income (8.5),ratio of electricity coverage (100%), households supplied with clean, potable water (93.3%),ratio of households with access to improved sanitation (85.4%), the proportion of area per individual in the family is 43.6 m 2 , with 99.6% of families residing in adequate accommodation, the ratio of homeownership with legal documents (93.9%), and the ratio of durable, structurally sound houses (92.8%) [51].However, other sub-indicator items need to be improved such as mortgage as a percentage of income (25.3% in 2021) [52] homeownership ratio (54.5% in 2022, which is lower than the national rate estimated as 60.6% in the same year) [51].These statistics indicate that many people face difficulties in obtaining quality housing.Furthermore, it establishes Saudi Arabian citizens seek ownership, not merely a dwelling, as homeownership is considered a source of stability and thus represents social value in Saudi community.Therefore, the equation of supply and demand is inequivalent, as population increase and rapid urbanization have accelerated demand for housing over time.As a result, most people have improved water, improved sanitation, electricity, a decent dwelling, legal homeownership, and sufficient living area, with an acceptable rate of homeownership.Despite several challenges in affordable housing, there is clear indication that progress has been made towards achieving SDG 11; thus, the government should review existing housing programs and reassess current difficulties of access to affordable housing.The assessment result for the target of public transportation establishes that the performance level is average, indicating an existence of major challenges.However, overall, public transportation in Al-Madinah is deficient, and as a result, private motor vehicles are used to access jobs and urban activities, leading to a car ownership rate of 1.7 cars per household, which is considered high compared to other countries [81].The key factor which must be considered here is the relatively low price for both fuel and motor vehicles, with household spend on transportation about 20% of total expenditure [82].This percentage is consistent with other Arabian Gulf cities, the USA and Europe, where expenditure for transportation ranges from 15% to 20%.Another stimulation for the high rate of car ownership is that the city's land use policy and master plans have allocated sizeable spaces for roads and roadside parking, which has encouraged the increase in car ownership.This excessive use of private cars has created many challenges for sustainable development, such as increased traffic congestion, parking difficulties, accidents, unsustainable economic costs, and environmental problems.However, the government has improved infrastructure in response to Vision 2030, with one of the most important changes being increased capacity for transportation infrastructure, with correspondingly increased satisfaction for local mobility requirements, as there is now more efficient access to socio-economic activities, and an average 15-minute drive from the CBD to residential areas, and an approximately 30-minute drive to any area of the city [51].On the other hand, the road network in Al-Madinah is almost redial, and includes the first ring road, King Faisal Bin Abdulaziz Road, which is 5 km long, Prince Abdulmajeed Road, the second ring road, King Abdullah Road, which is 27 km long, and the third ring road, King Khalid Road, which is 10-15 km.Finally, Omar Ibn Al-Khattab Road is the main link road which enables transportation between Macca and Jeddah to flow freely [52].The overall road network within the inner urban boundary is 5834 km, with road surface per capita at 4.2 meters; hence, there is an adequate proportion of transport infrastructure compared to global criteria [51].However, during the time of Hajj, most roads are heavily congested, which is another indication that establishing sustainable public transportation should be a high priority for the government.
The assessment result for the target of sustainable urbanization and participation establishes that the performance level is average, indicating an existence of moderate challenges.Al-Madinah has a population of 1,500,308 inhabitants (2020), with a population growth rate of 1.2 [52].Apart from rapid population growth in terms of permanent residents, the city attracts approximately 7 million visitors annually, particularly during the Hajj and Umrah religious tourism seasons [83].The responsiveness of local authorities to population growth, which is estimated to be 1.2% [52], is influenced not only by the capacity of the available infrastructure and services, but also by the ability of the authorities to manage this growth.Overall urban density is characterized by variation, with an average of 31.9/h(2020), with an overall built-up area of 44,800 hectares in the same year [52].However, this density can vary from one zone to another zone in the city; for example, the average density in the second Ring Road is more than 250 p/ha and ranges from 150 to 240 p/ha in the third Ring Road [84].Despite UN-Habitat recommendations that this region occupies only 5% of the overall built-up area, 50% of the population currently live there [84].
The total urban area of Al-Madinah is currently 943 km 2 [76].This implies that the increase in land consumption is greater than the increase in population, leading to the appearance of new settlements.This rapid urban growth has resulted in unsustainable consumption of city land, with the urban boundary expanding 1.5% between 2002 and 2015, while urban growth rate estimated to be 0.94 [85].Uncontrolled residential construction, almost all of which are non-compliant with planning regulations, are negatively associated with Access to green and public spaces Low Major land consumption.Uncontrolled areas constitute 4% of the overall urban footprint, accommodating 17% of people who live in the city [52].To achieve sustainable urbanization, the Saudi Arabian government adopted a community participation approach, allowing people to become involved in the preparation of detailed master plans.This approach is a segment of political reforms series that implemented in the context of Saudi governance over the last two decades.The key objective to adopt participatory approach is to achieve a balance between responsibilities and rights and enhance accountability and transparency norms.A sustainable development with a well-developed governance is more likely to achieve SDGs.In a practical sense, effective decisions often result from public participation in which all stakeholders are provided their opinions.In this vein, public participation provides knowledge and socio-economic benefits into municipal councils and politicians to make sound decisions about SDGs, particularly when short-term action is needed.The voter rate in the last municipal elections for the year 2015 was 47.3% [86], with women's participation as voters and candidates allowed for the first time in the history of Saudi Arabia.The main outcome of this public participation is the improvement of decision-making process, contributing to achieve progress in SDG 11.
Aldegheishem [87], Aldegheishem [88], Alamoudi et al [89] found empirically that the progress of smart sustainable cities in Saudi Arabia is related closely to the level of citizens' participation in decision making process.As a result, managing sustainable urbanization in Al-Madinah has witnessed several positive transformations.These transformations included improving infrastructure and social services, as well as rationalizing planning decisions made by public participation, contributing to affirmative progress towards SDG 11.
The assessment result for the target of preserving and protecting the natural and cultural heritage) establishes that the level of performance is relatively optimal.There are several reasons which have led to optimal progress for SDG 11, including: (1) the city has a religious, historical and archaeological heritage; given the presence of several major heritage assets, especially the Prophet's Mosque, which attract millions of visitors annually; (2) Private expenditure for cultural and natural heritage is high.For example, the number of visitors to Al-Madinah in 2019 exceeded 7 million, providing more than $1.6 billion for the local economy [83]; (3) public expenditure for preserving and protecting natural and cultural heritage rose from 3,510,982,482 SR ( i.e. $936,060,300) in 2016 to 12,625,069,091 (i.e.$3,365,959,822) in 2021 [90]; and (4) increased institutional capacity has also significantly improved the management of cultural and natural heritage by means of information dissemination, training quality, city marketing, management actions, following up, and control.
The assessment result for the target of air quality and municipal and other waste management establishes that the level of performance is low, indicating an existence of major challenges.In terms of basic services, the average per capita consumption of improved water is 358.95L/D [51].A higher water consumption rate can be directly attributed to the millions of visitors who visit during the Hajj and Umrah annually.More importantly, it should be noted that Al-Madinah is characterized by a lack of water and an increase in the use of groundwater in urban areas.Air quality is also a challenge, where the fine particulate matter (PM 2.5 ) increased from 32.68 μg m −3 in 2018 to 36.2 μg m −3 in 2023 [91].The concentration of PM 2.5 is currently 7.2 times the WHO annual air quality guidelines, leading to health problems for sensitive groups [91].These indicators demonstrate that the level of air pollution is moderate and increasable over time, and that reduction of this pollution can only be achieved by effective solutions, such as increasing green space and enhancing the use of renewable energy.While the ratio of households served by regular solid waste collection is 95.4%, recycling is lacking with a rate of only 10% [51].The daily rate for municipal solid waste in Saudi Arabia is estimated to be 1.4 kg per person in 2016 [92].However, most solid waste is disposed of by landfill, where the proportion of sanitary landfills/burials for inclusive coverage reduced from 100% in 2010 to roughly 92% in 2017 [51].There is also a lack of wastewater treatment plants, as well as reusing treated grey water.Therefore, it is important to establish the required infrastructure to improve the sewage revenue rate.
The assessment result for the target of access to green and public spaces establishes that the level of performance is low, indicating an existence of major challenges.It has been argued that increasing urban density leads to an increased demand for green spaces.Furthermore, as mentioned above, most of the residential housing is concentrated on the second Ring Road.Thus, demand for open spaces and public parks is high, and access to them is difficult.While agricultural land constitutes 23% of overall land use in the city, green areas are lacking, with a ratio of only 1% for the total urban area, and the per capita share of green areas is 4.9 m 2 / person in 2020 [51].Furthermore, public spaces such as gardens and playing spaces are also sparse.In this context, the current rate for vacant land is close to 31% of the total area, with 12% of the overall developable land lying within the built-up areas, providing opportunities for increasing green spaces [51].It should be noted that a lack of green areas and public spaces is related to many factors, including insufficient budget allocation, the unavailability of modern technology used to design green areas, and the lack of specialized engineering equipment which could be utilized for designing green areas.Increasing green areas and public spaces is a major priority to improve sustainable urbanization.

Conclusion and policy implications
The study focused on assessing progress towards SDG 11 in Al-Madinah by establishing an analytical framework covering six targets of SDG 11, with 40 indicators.According to the assessment, overall performance of SDG 11 has shown significant improvement considerably, particularly after Vision 2030 was approved.The findings show that three targets including affordable housing, sustainable transportation, and sustainable urbanization and participation, have achieved average performance, and two targets, including air quality, municipal and other waste management, and access to green areas and public spaces have been demonstrated poor performance, as well as a single target, which is the preservation and protection of natural and cultural heritage, which has achieved optimal performance.The results highlight several challenges that hinder progress of SDG 11, and the level of these challenges varies from one target to another target, ranging from average to major challenges.Hence, it is difficult for Al-Madinah to fully optimize all SDG 11 indicators simultaneously, as progress levels are varied, and the association between indicators is complicated.Local authorities could thus prioritize sub-indicator items that caused challenges by means of urban policies and technical instruments.These priorities include creating an effective public transport system, considering untreated wastewater, rationalizing water consumption, improving mortgage facilities, and expanding green areas and public spaces.These challenges should be considered by urban authorities and might be reduced by establishing a resourcesaving community and innovative urban renewal programs.A resource-saving community can be achieved by reducing current high water consumption, particularly in agriculture sector, and reducing energy consumption through utilizing solar energy, using electric cars, and establishing smart and sustainable transportation system.These policies also contribute to reducing carbon dioxide and preserving the environment.
To achieve optimal results, a sustainable evaluation system needs to be established, with consideration of all sub-indicator items required to track the progress towards sustainable development.Activation of cooperation channels between urban authorities and universities is necessary, including skill-building and training programs for innovative solutions to urban challenges, could contribute to optimal achievement of SDG 11.
In this study, the analytical framework for sustainability assessment provides important insights into SDG 11 progression in Al-Madinah.It can also be used as a base to establish a tracking system for other cities in Saudi Arabia and Arabian Gulf cities. Thus, the government should use the results of assessment in the decision making process for urban policies.Tracking system requires creating database by urban institutions.The database should include information about all indicators of SDGs and their measurement ways at international, national, and local levels.With up to date database we can understand what strategies are most successful at tracking scale can we accelerate progress toward the achievement of SDG 11.
The use of international indicators of SDGs, particularly SDG 11, at local level should be considered technical issues of normalization, and weighting, as well as conceptual matters of indicator selection.To encounter these difficulties, the selection of indicators should be guided by establishing conceptual frameworks to cover social, economic, environmental pillars of sustainability.Finally, the results of study can enable researchers, planners, and decision makers to see practices of SDGs in Saudi Arabia.
Like other many studies in the context of sustainable development, this study has a number of limitations.Due to limitation of public data, this study has investigated 6 sub-goals of SDG 11, with 40 indicators, out of 9 sub-goals.Future research should focus on uninvestigated sub-goals such as managing disasters, linking between urban, peri-urban and rural areas, and integrated policies towards inclusion and resource efficiency.Another limitation, this study has focused on a single case study, which is Al Madinah, and thus future research should take into account multiple cities in Saudi Arabia.
was collected from public sources including Voluntary Local Review (VLR) of Al Madinah City developed by Al Madinah Region Development Authority and Urban Observatory in 2023, City Socio-Economic Survey (CSCS) developed by Al Madinah Region Development Authority in 2021, statistical reports issued by the General Authority for Statistics (GAS), and reports developed by the Ministry of Investment (MI).However, two indicators were collected from the literature.Appendix A presents sources of the values of indicator items used in this study.
4.1.Classification of indicators' valuesTable1shows classification of indicators' values for the SDG 11.Indicators' values were assessed by experts.The results illustrate that 11 indicators were classified with low values, implying the application of the first equation, mentioned in the methodology section, in order to calculate the overall level of performance for SDG 11.However, 8 indicators were classified with optimal level and 21 indicators classified with average level, suggesting the application of the second, third, fourth, and fifth equations.The results illustrate that experts' assessment implies that the highest classification is accounted for preserving and protecting natural and cultural heritage, with a value 9.67 out of 12.The lowest values emerged by two targets: (1) air quality, municipal and other waste management, and (2) access to green areas and public spaces.

Table 3 .
Level of progress and challenge towards SDG 11.