The Role of Accessibility to Achieving Sustainable Revitalization of Historic City Centers: A Study of the Historic Center of Al-Kifl City, Iraq

Revitalizing urban centers through enhancing accessibility constitutes a crucial strategy for promoting sustainable urban development and improving quality of life. Urban spaces prioritizing accessibility foster vibrant environments, reflecting individuals' capacity, regardless of their physical, sensory, or cognitive abilities, to efficiently and sustainably access opportunities, services, and resources available in urban centers [33]. Moreover, accessibility relies on inclusive infrastructure design that considers everyone's needs by applying the principles of universal design. Therefore, accessibility is not merely an issue of social justice but a fundamental aspect of sustainable revitalization policy aimed at achieving long-term sustainability [34]. The factor encompasses four key indicators:(diversity in traditional transportation modes, sustainable transportation modes, functional proximity, and transportation infrastructure). Each primary indicator and its sub-indicators will be elaborated upon in detail.

4.1 Diversity in traditional transport modes

Diversity in traditional transportation modes reflects the availability and variety of transport services within urban centers, enhancing their vitality and appeal. It encompasses walkability, cycling, public transit, and private transport, necessitating advanced infrastructure for efficient support. This metric is assessed through specific sub-indicators [35].

4.1.1 Pedestrian movement

Pedestrian movement constitutes a vital component of daily life, playing a significant role in revitalizing urban centers. It serves as an effective alternative to other transportation modes in terms of cost-efficiency and enhancement of public health, as well as significantly fostering social interactions among community members [35]. According to international standards for analyzing pedestrian flow, the Voronoi diagram a mathematical method for spatial partitioning based on the distances between existing points is utilized to measure pedestrian density. This approach assigns a specific space to each individual within a crowd, representing the nearest distance to that individual relative to others. Pedestrian flow is considered smooth and stable when pedestrian density remains below 3.9 persons/m². A density ranging from 3.9 to 4.33 persons/m² is deemed acceptable for sustainable revitalization of urban centers. However, when density exceeds 4.33 persons/m², pedestrian movement becomes dense and uncomfortable, accompanied by noticeable crowding and reduced mobility [36].

$D v=N / \sum_{i=1}^n|A i|$                 (1)

where, Dv represents density according to the Voronoi diagram, N denotes the number of pedestrians within the studied area, and Ai indicates the area of the cell allocated to pedestrian i.

4.1.2 Bicycle

Cycling represents an effective means for urban center revitalization due to its potential to reduce traffic congestion and harmful emissions, thereby improving air quality. Additionally, bicycle mobility enhances public health by encouraging physical activity and assists in organizing urban spaces, making cities safer and more attractive to tourists [37]. This indicator will be assessed by measuring cycling density using the (k-means clustering model) within cluster analysis performed through the statistical software SPSS and subsequently represented within a Geographic Information Systems (GIS) environment (ArcGIS). This approach relies on grouping urban areas into homogeneous clusters based on a set of relevant cycling-related variables, such as routes and density, aiming to identify regions with higher bicycle traffic, according to the following equation [38]. The moderate density of cycling traffic is considered both acceptable and desirable. Table 1 presents the standards for cycling density in historical urban centers.

$J=\sum_{i=1}^k \sum_{x i \in c}\|x-u i\|^2$                (2)

where, J represents the total within-cluster variance, (k) denotes the number of clusters, Ci represents cluster i, which contains a set of similar data points, X denotes a data point within the cluster, and Ui refers to the centroid of cluster i.

Table 1. Criteria for determining density levels for bicycle traffic

4.1.3 Private vehicles

Private transportation involves individuals traveling via non-public means, primarily private vehicles. Although it enhances personal comfort and mobility within major cities, excessive reliance on private transport creates challenges such as traffic congestion and environmental pollution [39]. This indicator will be assessed using the (Greenshields Model) for measuring traffic flow based on criteria provided in Table 2. Data from selected field survey points will be recorded, analyzed, and represented using ArcGIS [40-46]. To support urban center revitalization, the lowest acceptable density is recommended, preferably limited to the center's boundaries, thereby reducing congestion and pollution and safeguarding historical centers.

$q=v . k$                (3)

where, q represents the traffic flow volume, v denotes vehicle speed, and k indicates the traffic density per km².

Table 2. Criteria for determining density levels for private vehicle traffic

4.1.4 Public transport buses

Bus transit is integral to urban transportation systems, enhancing mobility efficiency, transportation diversity, and meeting community needs within historical centers, thus facilitating their revitalization. It is widely used due to its route flexibility and extensive urban coverage, characterized by interconnected networks and strategically placed stations that meet user requirements [40]. This indicator will be quantitatively assessed in a Geographic Information Systems (GIS) environment by identifying public transit routes and bus station locations, analyzing service coverage according to international standards (300–500 meters within a 5–10-minute travel time). This approach improves accessibility, reduces dependence on private vehicles, supports efficient mobility, revitalizes urban centers, and lessens environmental impacts [41].

4.2 Sustainable transport patterns

Sustainable transportation, (including electric and automated transport), refers to a set of systems designed to efficiently meet mobility demands within urban centers, thereby restoring their vitality and activity. Electric transportation contributes to reducing emissions by utilizing renewable energy, while automated transport enhances usage efficiency and reduces congestion through autonomous driving technologies [42]. It encompasses the following:

4.2.1 Automated vehicle

Automated transportation is pivotal in revitalizing urban centers by providing intelligent transport solutions that enhance traffic flow, reduce congestion and harmful emissions, and foster dynamic urban environments [43]. This transportation mode utilizes advanced computing devices and precise sensors for accurate vehicle positioning and environmental interaction, alongside intelligent infrastructure comprising high-frequency signals and visible signage for regulating speed and responding to traffic signals [44, 45]. Its assessment, conducted via Geographic Information Systems (GIS), involves identifying automated transport stations within a maximum distance of 500 meters and a travel time of 5-7 minutes, including dedicated routes spanning (20-40 km) and equipped with road (sensors, surveillance cameras, signage, and emergency systems).

4.2.2 Electric vehicle

Electric transportation represents a fundamental approach to revitalizing and energizing urban centers by offering sustainable transport solutions based on clean energy, thus significantly enhancing accessibility within urban areas. Electric vehicles provide convenient and rapid transportation, accommodating capacities ranging from (2 to 120 passengers [46]. Prominent city landmarks are serviced via strategically located stations reachable within (5-7) minutes on foot [47]. To ensure comprehensive coverage, dedicated routes extending (30-50) km are established, with stations distributed at intervals of (500-1000) meters. These stations are equipped with surveillance cameras and intelligent signage to enhance safety and efficiently guide vehicles [48].

4.3 Functional proximity

Functional proximity contributes to creating integrated and interconnected urban environments by concentrating a range of functions within spatially proximate locations that are easily accessible. This principle aims to reduce dependence on transportation modes, thereby decreasing commuting time between workplaces, residences, and recreational areas, enhancing urban center attractiveness and vitality [49]. It includes the following:

4.3.1 Residential district and neighborhood center

Accessibility to neighborhood and residential district centers is pivotal for revitalizing historical centers, aiming to reduce travel distances and encourage walking instead of private vehicle use. This approach increases pedestrian activity, fosters community engagement in public spaces, and enhances urban vitality, thereby promoting diverse activities and maximizing local amenity utilization. This indicator will be assessed using Geographic Information Systems (GIS) by defining walking distances of 400 meters to neighborhood centers and 800 meters to residential district centers [26].

4.3.2 Network connectivity

It refers to the network's capacity to facilitate efficient movement and connectivity between areas within the urban center. Effectively interconnected networks are crucial in creating vibrant, dynamic urban environments, as they minimize distances between various zones, enhancing accessibility and simplifying individual mobility [28]. This indicator will be assessed using the "Gamma Index" method, measuring the ratio of actual network connections to possible connections based on a mathematical formula. The Gamma Index values range from 0 to 1; values approaching 1 indicate greater network connectivity and integration [50]. Additionally, it will be represented using the "DepthmapX" software.

$Gamma \,\,Index=\frac{E}{(V-2) 3}$              (4)

where, E represents the number of links, and v denotes the number of nodes.

4.4 Transport infrastructure

Sustainable revitalization policies emphasize transportation infrastructure to improve accessibility in historical centers. Well-planned parking facilities alleviate congestion, reduce accidents, and enhance air quality, while smart management solutions optimize efficiency [51]. Inclusive access for individuals with disabilities is ensured through designated parking with ramps and auditory signals, promoting independence and urban appeal [52].

Figure 6. The main and sub-indicators of accessibility and measurement method

6.1 The historical center of Al-Kifl City

The city of Al-Kifl is one of the cities within the Al-Kifl District in Babil Governorate, Iraq. It is strategically located between three major governorates: Babil, Najaf Al-Ashraf, and Karbala Al-Muqaddasa. The city's geographical coordinates are 32°13′36″ N latitude and 44°22′2″ E longitude, with an elevation of 30 meters above sea level. Al-Kifl is situated 30 kilometers southwest of Hilla’s city center, 10 kilometers north of Kufa, and 60 kilometers south of Saddat Al-Hindiya. It is bordered to the north by Hilla, to the west by the Euphrates River, to the south by Najaf Al-Ashraf, and to the east by vast agricultural lands belonging to Babil Governorate. Throughout history, Al-Kifl has held significant importance, as it was part of the ancient Babylonian kingdom. The city derives its name from the shrine of the Prophet Dhul-Kifl (PBUH), making it a unique model of human civilization. Over centuries, it has remained a meeting point for the Abrahamic religions and a vital hub for trade and cultural exchange in Iraq. The city's geographical and historical significance is illustrated in Figure 8 [57, 58].

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Figure 8. Location of the study area in Al-Kifl City

The Old Qasbah serves as the historical core of Al-Kifl, around which the city developed and expanded over the centuries. The population of the Old Qasbah stands at 4,245 residents, constituting 15.9% of Al-Kifl’s total population of 26,614, distributed across 1,033 households, resulting in an average household size of 5.4 individuals. The Old Qasbah covers an area of 34.7 hectares, representing 10% of Al-Kifl’s master plan area of 429 hectares and 17.2% of the city's residential neighborhoods, totaling 202.3 hectares. The area contains 805 residential units, yielding a population density of approximately 233 inhabitants per hectare [59].

The Old Qasbah is a living testament to religious and cultural coexistence throughout history, as it hosts numerous religious landmarks spanning various faiths and historical periods. This highlights its significance as a historical and cultural hub. The demographic and spatial characteristics of the Old Qasbah are documented in the Urban Renewal Report for the Shrine of the Prophet Dhul-Kifl and Its Surrounding Areas (Directorate of Statistics, Babil).

The historical city of Al-Kifl holds global significance due to the shrine of the Prophet Dhul-Kifl, a sacred site revered by Muslims and Jews. Until the mid-20th century, Al-Kifl functioned as a religious nexus, hosting major Jewish celebrations attended by thousands of Iraqi Jews twice annually, underscoring its role in cultural and religious interaction. Locally, Al-Kifl is an agricultural hub, benefiting from its strategic location on the Euphrates River and fertile lands that produce wheat, rice, and barley. The city also features notable historical landmarks, such as the Al-Nukhaila Mosque, with its conical minaret from the reign of Sultan Abu Sa'id Bahadur Khan (730 AH), and Daniel’s Historic Market, exemplifying historic Muslim-Jewish coexistence. Efforts are underway to nominate these sites for UNESCO’s World Heritage List, recognizing their cultural and historical value [59, 60].

The Tomb of Ezekiel serves as Al-Kifl’s urban focal point, both functionally and visually. Its hybrid architecture, blending Ottoman minarets, Islamic inscriptions, and remnants of Jewish symbols, defines the city’s skyline. The adjacent historical market square reinforces the shrine’s centrality as a transitional space between sacred and secular realms. Urban studies emphasize the symbiotic relationship between the shrine’s vertical dominance—marked by its dome and minaret—and the surrounding low-rise brick structures, forming a hierarchical urban composition that highlights its spiritual prominence. hierarchical urban composition that amplifies its spiritual significance.

The historical center of Al-Kifl integrates religious institutions, including madrasas, libraries, and shrines, creating opportunities for sustainable revitalization. The urban fabric is dominated by traditional brick architecture with ornate geometric facades and enclosed courtyards, contrasting with modern concrete structures on the periphery.

Despite restoration efforts, such as the shrine’s foundation reinforcement in 2016, the area faces challenges from uncontrolled urbanization, incompatible modern interventions, and environmental degradation. Key concerns include preserving narrow alleyways (often under 3 meters), culturally sensitive redevelopment of vacant lands, and mitigating visual encroachments from modern projects [60, 61] (Figure 9).

9.png

6.2 Urban fabric of the historic center of Al-Kifl City

The historical center of Al-Kifl has undergone structural transformations, with unregulated expansion weakening its connectivity to surrounding areas. Enhancing urban transport networks and pedestrian corridors is key to reintegrating the center with residential and economic zones [60].

With its strategic location and diverse activities, Al-Kifl possesses the characteristics of a traditional Islamic urban center (Figure 10, Table 3). Achieving this requires balanced planning policies that preserve architectural heritage while supporting economic activity, ensuring the historical center’s functional continuity [62].

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Figure 10. Land uses of the study area by using GIS analysis and data from Al-Kifl municipality

Table 3. Land use area in the historical center of Al-Kifl City, from data base of Al-Kifl municipality

The shrine of Prophet Dhul-Kifl and other religious sites serve as significant religious and tourist attractions, necessitating improved transport systems to boost economic and service-sector activity in adjacent areas, fostering a dynamic and sustainable urban environment. Climatic conditions present urban planning challenges, requiring sustainable strategies such as using local materials for heritage restoration and improving shading networks to mitigate environmental impacts. Historical transformations underscore the need for integrated strategies that sustain the historical center’s vitality through continuous urban activity [63].

Amid rapid environmental and social changes, enhancing accessibility to Al-Kifl’s historical center is central to urban conservation strategies. This demands a comprehensive approach balancing cultural heritage preservation with economic and environmental adaptability, ensuring the city's urban sustainability in a contemporary context [59].

Figure 12. Increase in private vehicle traffic flow according to the Greenshields model using SPSS

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Figure 13. Field survey routes, spatial distribution of bicycle use density, public transport routes, public transport stations, and service area of the public transport station in the historic center of Al-Kifl City using GIS

(4) Public transport buses

Field surveys indicated that public transport service in Al-Kifl relies primarily on 14-passenger minibuses operating solely along the main arterial road (Figure 14). The city possesses only one terminal, situated on the periphery of the historic center, with no additional stations or stops within the historic fabric itself. Consequently, effective service coverage is concentrated within a narrow radius of approximately 300 to 500 meters from this terminal and main route.

14.png

This situation reveals severe deficiencies in the current public transport system regarding spatial coverage and infrastructure. Reliance on a single route and terminal leaves large portions of the historic center effectively unserved, creating significant accessibility barriers for residents and visitors who lack private vehicles or prefer not to use them.

Such inadequacy in public transport provision critically undermines the objectives of sustainable and inclusive revitalization. It fails to offer equitable access for all to the historic center and its amenities, and inevitably forces greater reliance on private vehicles, thereby exacerbating congestion and pollution. Therefore, revitalization strategies must incorporate fundamental improvements and expansion of the public transport network as a core component. This should involve exploring options for new intra-center routes (using appropriately sized vehicles), increasing service frequency, establishing safe and convenient stops, and potentially integrating complementary public transport modes to ensure effective and sustainable access for everyone.

6.3.2 Sustainable transport patterns

Field surveys revealed a complete absence of automated public transport systems (e.g., autonomous shuttles, Personal Rapid Transit) and a lack of widespread adoption of electric transport modes within Al-Kifl's historic center. Furthermore, there is a clear deficiency in the essential supporting infrastructure required for such advanced systems, including equipped stations, dedicated routes, and smart surveillance and guidance systems.

This absence signifies the historic center's total reliance on conventional transport modes and a lag in embracing modern developments in sustainable and intelligent mobility. The lack of supporting infrastructure reflects not only a technological unpreparedness but also highlights deeper challenges related to urban planning and spatial allocation within a sensitive and complex historic fabric.

Although implementing some advanced technologies poses challenges in a historic context, neglecting to plan for or explore the integration of context-appropriate sustainable transport solutions (automated or electric) signifies missing future opportunities to enhance mobility efficiency, significantly reduce environmental impact, and improve quality of life. Therefore, sustainable revitalization strategies should encompass feasibility studies and long-term planning to consider the potential introduction of clean and smart transport technologies that are sensitive to the heritage context. The aim should be to improve overall accessibility and transform the center into an attractive, balanced urban area that meets sustainability goals while preserving its historical identity.

6.3.3 Functional proximity

(1) Residential district and neighborhood center:

The studies area integrates characteristics of both a residential district (as per municipal boundaries) and a neighborhood unit (based on its population of 4245 residents). Accessibility patterns to the service center were analyzed within two radii: 400 meters for the neighborhood center and 800 meters for the residential district center. A central point was designated to represent the service center, and network analysis within a Geographic Information Systems (GIS) environment was employed to delineate service coverage based on the road network of the historical center.

The results demonstrated comprehensive coverage for all residents, this high level of current accessibility is an important strategic asset and a key feature of the sustainable activation process. It promotes walking, reduces the need to use vehicles for short daily trips, and supports social cohesion and interaction within the neighborhood. Therefore, activation strategies must prioritize maintaining and enhancing this feature see Figure 15.

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(2) Network connectivity

Analysis of the road network identified 100 links and 148 nodes. Application of the Gamma Index to assess network connectivity yielded a value of 0.23. Spatial analysis using DepthmapX further revealed that high connectivity levels are confined to the city's main road and a few central axes, while most other parts of the historic center exhibit low connectivity and lack functional road integration.

The very low Gamma Index value signifies poor overall functional efficiency of the network and limited route choice availability. This is primarily attributed to the organic nature of the historical layout, where the network evolved in an unstructured manner over different periods responding to residents' needs, resulting in poor integration between different parts of the center despite node concentration around key landmarks like the historic Al-Nukhaila Mosque.

While reflecting historical authenticity, this low and fragmented connectivity can impede ease of movement and navigation within the historic center, particularly for unfamiliar users or services. It may also lead to the isolation of certain areas and potentially limit economic vitality. Therefore, while respecting the historic layout, revitalization strategies should aim to improve navigability through clear and effective signage systems and readily available spatial information. Furthermore, the feasibility of creating strategic pedestrian linkages at specific points could be explored to enhance permeability and functional integration without causing major disruptions to the historic fabric, thereby supporting a more vibrant and integrated historic core see (Figure 16).

16.png

A custom tool was developed by the researcher to calculate the Gamma Index, accessible via: https://d49v88.csb.app/.

6.3.4 Transport infrastructure

(1) Parking

The field survey identified three parking facilities: one privately owned on the left side of the study area (1,490 m²) and two associated with the historic Al-Nukhaila Mosque (1,400 m²). GIS Nearest Neighbor Analysis revealed a highly dispersed distribution pattern for existing parking facilities (NNR = 5.95), significantly exceeding expected random distribution and indicating spatial inefficiency. Network coverage analysis further showed that parking service is heavily concentrated around major historical landmarks, leaving other parts of the historic center underserved. Critically, a complete absence of dedicated parking facilities linked to sustainable public transport within 500 meters (i.e., park-and-ride) was observed.

This simultaneously dispersed yet concentrated pattern signifies an inefficient, ad-hoc parking system that lacks strategic planning and fails to serve the historic center uniformly or adequately. The absence of park-and-ride facilities highlights a major gap in integrating parking management with broader sustainable transport objectives.

This inefficient and poorly integrated parking system negatively impacts accessibility, contributes to visual clutter and potential heritage degradation (in cases of uncontrolled on-street parking), and fails entirely to support sustainable mobility goals. Therefore, sustainable revitalization necessitates a comprehensive parking management strategy. This strategy should involve optimizing the management of existing spaces, potentially consolidating parking into well-designed facilities (preferably peripherally located), implementing control measures (e.g., pricing, permits), and crucially, developing dedicated park-and-ride facilities that are well-connected to improved public transport services, aligning with recommended sustainable revitalization policies, see Figure 17.

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Figure 17. Streets in the historic center of Al-Kifl

(2) People with special needs

Field surveys confirmed an almost complete absence of essential accessibility facilities for people with special needs – such as adequate ramps, accessible pathways, and elevators in public buildings – throughout the historic center.

This severe lack of facilities constitutes a major physical and social barrier, effectively preventing individuals with disabilities and the elderly from navigating the center independently and participating fully in its activities. This situation is interpreted as stemming from weak public policies concerning universal access, the lack of clear and binding regulations mandating universal design standards, and historical neglect by planning and executive authorities.

The exclusion of a significant segment of the community due to physical barriers directly contradicts the principles of sustainable, equitable, and socially inclusive revitalization. Ensuring access for all is not merely a technical requirement but a fundamental aspect of social equity and urban quality of life. Consequently, revitalization plans and strategies for Al-Kifl's historic center must prioritize addressing this deficiency systematically. This necessitates the integration and application of Universal Design principles across all public realm improvements (providing ramps, tactile paving, clear routes, accessible restrooms, available information) and within public and heritage buildings (where technically feasible and respecting heritage values), in order to create a truly welcoming and usable historic center for everyone, without exception. Table 5 provides a summary of all indicators.