Assessing accessibility of footpath-level walkability in old core cities of India for promoting Universal Mobility through Architectural Planning Research: Case Study of Central Kolkata, India

: In this research, the accessibility in the footpath-level walkability condition of old core cities of India has been assessed, considering Central Kolkata, India as a case. Post-2015, after the implementation of Goal Number 11 of United Nations Sustainable Development Goals (i.e. Sustainable Cities and Communities), the significance of universal mobility has globally manifolded in the walkability sector. This research has been done in theoretical, ideological, and methodological patterns using Architectural Planning Research for promoting Universal Mobility in old Indian cities. The variables (categorical) used in this research are related to pedestrian infrastructure. The categorical variables are: 1) Building Typology of Stretch, 2) Footpath Dimensions, 3) Temporary Encroachment, 4) Permanent Encroachment, 5) Bus Stop, 6) Metro Rail Entrance, 7) Railings, 8) Storm Water Drains, 9) Public Toilet, 10) Trash Bins, 11) Street Lights, 12) Flooring, 13) Manholes, 14) Kerb, 15) Pedestrian Crossing, 16) Street Furniture, 17) Safety and Security, and 18) Additional Inclusive Features like signage. This research shows that the footpath stretches in Central Kolkata, India are inadequate in terms of ideal accessibility. In addition to this, the result of this research portrays complexities in the adaptability of accessible walkability-related considerations; thereby suggesting a new accessibility audit format for old core Indian cities for achieving Universal Mobility standards in the future. The authors also propose quantitative methods to conduct future research in the same domain. investigation, G.D.M.; resources, S.M., R.N. and G.D.M.; data curation, G.D.M.; writing — original draft preparation, G.D.M.; writing — review and editing, S.M. and R.N.; visualization, G.D.M.; supervision, S.M. and R.N.; project administration, S.M. and R.N.; funding acquisition, S.M.


Introduction
"Architectural Planning" is a generality-oriented deterministic way of relating physical and spatial factors with human life [1]. Architectural Planning Research (hereafter, APR) reflects human behavior in the built environment. The adequacy and contextuality of APR depend on three primary factors: 1) Contextual appropriateness, 2) Economic Viability, and 3) Diversification of User Group. Amongst all, the understanding of the user group is the key to a successful APR solution [2]. The role of Universal Design (hereafter, UD) is primary in this argument. UD has an essential niche in APR due to a higher degree of psychophysiological quotient than most other design paradigms. UD is defined by Ronald Mace (1985) as the design of products and environments which would be to maximum usable by all people, without the need for modifying or specializing the design [3]. However historically, amidst iconic placemaking and timeless design, architects and planners have not been able to integrate the entire user group in a holistic manner. A recent example is a case of the Constitution Bridge on the Grand Canal in Rome, where the suggests were used by the authors in the preparation of the questionnaire for this research. The factors are: (a) Resting space, (b) Age-friendly pavements, (c) Safe pedestrian crossings, (d) Accessible features, (e) Walkways and cycle paths, (f) Adequate Public toilets, (g) Availability of Public Transport, and (h) Age-friendly Transport stops and stations [19]. In addition to this, India being a member nation of the United Nations and taking cue the inputs from "United Nations Convention on Rights of People with Disabilities" (UNCRPD) and other similar international guidelines, had to incorporate certain elements of inclusiveness in the present Urban Development paradigm. As a result, programs like (1)"Sugamya Bharat Abhiyan" or "Accessible India Campaign" in 2015 [20], and (2) "Building Accessible, Safe & Inclusive Indian Cities" or BASIIC in 2020 has been adopted in India to promote Universal Design [21]. Amongst all the domains of Universal Design like "Building level factors", "Information and Communication segment", "Movement and Transportation Issues" and "Site Level features", the topic of "Movement and Transportation Issues" has been dealt with major focus in this research. "Movement and Transportation Issues" is prioritized since individual building facilities alone cannot create Universally Designed cities unless those buildings are connected through a "Universally Designed" movement corridor. The aforesaid universally designed movement corridor is also referred to as Universal Mobility in technical terms.
This research attempts to propose a model of walkability assessment of historical city centers, and then verifies the model on case area. The core of Kolkata, India has been selected as a case area for this research. The next section elaborates on the historical background of the case area.

Historical Development of the case area
Indian old cities are different from many old cities around the world due to their diverse historic origin, complex transformation dynamics, and organic spatio-formal structure. The old city selected for this research is Kolkata, which is the capital of the state of West Bengal in India due to its historic origin and decaying urban core. As early as the 16 th century, Portuguese presence can be traced in and around Kolkata [22]. Armenians also had their presence in this city in the late 16 th century [23]. The early 17 th Century marked the arrival of the Dutch near Kolkata [24]. French too had made their presence near Kolkata by the late 17 th century [25]. However, the major physical and social impact on the city is of the British who institutionalized the city (for their own benefit) and converted it into a city of global interest since their advent in 1690 [26]. Kolkata was also the capital of British India till 1911 [27]. After gaining independence from the torturous British Empire in 1947 [28], Kolkata remained as the centre of trade, commerce, politics, and culture; despite being plagued by various socio-political crises [29].
During the period 1947-1977, Kolkata was majorly under the rule of the Indian National Congress except for the short rule of the United Front (from 1967-1969) [30]. After this period, from 1977 till 2011 Kolkata was ruled by the Left Front (Communist Party of India-Marxist) [31]. From 2011 till date, the All India Trinamool Congress has been in power [32]. In addition to this, mostly since 1977, the ruling party in the Central Government of India has not been in consonance with the ruling party in the State Government of West Bengal (consisting of Kolkata). Thus, many beneficial national policies have not been materialised at the state level, especially since Indian Constitution (vide Article 246) mentions the control of State administration in urban development projects [33]. The old (central) part of Kolkata which has traditionally been the administrative, commercial, and educational hub has been historically associated with congestion and unhealthy living conditions [34]. The case area selected for this research in Central Kolkata has been mentioned in the oldest cartographic evidence of Kolkata prepared during British Empire. Kolkata Municipal Corporation (established in 1876) is presently responsible for the administration of the delineated case area (Refer Appendix 1).
The case area selected for this research spans over nearly 850m and is aligned in North-East to South-West direction. The footpath (pedestrian area) on both the side of the case area is the specifically surveyed stretch. Since the inception of Kolkata in the late 17 th century, this case area has been the centre of multiple activities and associated traffic loads. The temporal change of this area (especially the "right of way" or R.O.W.) has not been proportional to an increase in population as well as associated activities. The population of Kolkata in 1911 was 896,067 in comparison to 4,496,694 as per the 2011 census. However, the average density of Kolkata (Municipal limits) in 1913 was approximately 26,500 people per square kilometre, in comparison to 24,252 (as per the 2011 census).
In similar lines, the traffic intensity map prepared by E.P. Richards in the year 1913 for Calcutta (previous name of Kolkata) Improvement Trust shows that even 100 years ago, the study area maintained a traffic intensity of 500 vehicles per hour. Subsequently, in this case area, there has been an addition of Metro Rail (underground rail/ subway) in the early 1990s; followed by mobile application-based rental cab services post-2000s. However, the case area has almost the same R.O.W. since 1913.
In relation to this, a survey by the authors in the month of September 2020 shows the number of total vehicles in peak hour as: 1) 2110 vehicles in Bowbazar Crossing, 2) 5483 vehicles in Central Avenue Crossing, and 3) 11211 vehicles in Bentinck Street Crossing. The survey format and details of the study are provided in Appendix 2. It should also be noted that due to the coronavirus pandemic, several Building Uses (including schools and private institutions) were not functioning regularly, thus considerably reducing the peak hour vehicular traffic volume recorded by the authors.
Thus, it can be concluded that, despite having the same density, the number of vehicles per hour has increased manifold; thus, putting infrastructural pressure (specifically walkability) on the sidewalks. In relation to this, research work in a similar case area, titled "Re-inventing Urban Spaces by accessing accessibility in old city core-A case of Kolkata", had concluded that the greatest problem in walkability is: 1) Lack of proper footpath-for able-bodied people, and 2) Encroachment by Vendors-for differently-abled people [35]. Also, visual observations by authors reflect that the present condition of the case area is not adequate for pedestrians and the issue of universal mobility seems like a daunting task.
The case area for this research is shown in Figure 1. The case area selected for this research area is further subdivided into thirty-two stretches (Explained in detail in the "Research Design" section of this paper) for strengthening the specificity of the research. The stretches are: 1) Arterial Streets, and 2) Footpath stretches between two adjacent Arterial Streets. Apart from these stretches, there are three major junctions that this stretch surpasses: Bowbazar Crossing, Central Avenue Crossing, and Bentinck Street Crossing. In all the thirty-two stretches delineated for survey in this research, the presence of residential and business building-use is observed. Buildings with mercantile Building Use are present in 71.88% (23 nos.) stretches. Subsequently, in 50% (16 nos.) stretches, Institutional Building Use is observed. Other Building Use in the thirty-two stretches are: a) Educational -12.50% (4 nos.), b) Assembly -6.25% (2 nos.), and c) Industrial and Storage -3.13% (1 no.). Hazardous Building Use is not observed in any of the stretches. The presence of different building-use in the case area is shown in Figure 2. The next section is the Literature Study, which is a theoretical commentary on the critically prioritized aspects of mobility.

Literature Study
Gregg and Hess (2019) argue about the contextual analysis of public policies related to street-level research. The understanding of a complete (ideal) street is based on the components that the street has or might be induced; not necessarily based on a generic guideline [36]. Dividing the case area into multiple segments helps to understand the components of "time and rhythm" in public space [37]. Identifying the functionality associated with each sub-section of a relatively long stretch of the street; and classifying individual infrastructural needs based on this hierarchy is an alternative way of analysing urban mobility [38]. Martire (2017) emphasizes connecting urban history with the street genre and street pattern. The transformation of the urban fabric with respect to temporal change is an essential consideration in the architectural planning for urban mobility [39]. In similar lines, according to the theory of Natural Movement (Space Syntax), the urban spatial structure influences the movement pattern [40]. Mahdzar (2013) suggests empirical observation of pedestrian activities before mapping the surveyed stretch. Mahzdar (2013) also mentions the categorization of physical elements of analysis into: 1) Building, 2) Street, and 3) Land Use [41]. In the same way, spaces should be analysed from the viewpoint of element spaces in order to assess the universal nature of the space [42]. Southworth (2020) has established the intricate relationship between soundscape and visual environment, which is a step towards creating an environment of universal nature [43]. Geurs and Wee (2004) establish that for urban infrastructure, the four major bases of accessibility measures are: 1) Infrastructure, 2) Location, 3) Person, and 4) Utility [44]. There are numerous ways to evaluate the accessibility of urban infrastructure, including complex ones like "Non-numerical Unstructured Data Indexing Searching and Theorising" (NUD-IST 4.0) [45]. Similar accessibility measurements also include the Public Transport Accessibility Index (LUPTAI) and the Public Transit and Walking Accessibility Index (PTWAI). Similar tools include The Path Environment Audit Tool or PEAT [46] or Mesurement Quality Appraisal Instrument or MQAI [47]. The major concern in assessing accessibility is the "relative accessibility" because accessibility is a comparative component in urban infrastructure [48]. Quite close to "relative accessibility" is the concept of "perceived accessibility", which is a measure of living a satisfactory life using public transportation [49]. The composite measures of modal experience can be acquired through a cognitive understanding of a built environment. Along similar lines, wayfinding and its associated travel experience of an individual pedestrian can be ideally explained by cognitive maps [50]. In % of Streets addition to this, urban cores having historic origin (like the case area for this research) need "Conservation Assessment" besides generic Accessibility Audit [51].
Instead of overarching national guidelines, a Local Accessibility Plan is better suited for Indian cities [52]. Owing to the Indian practice of extensive use of public transport and walkability for daily commuting, the urban structure considerably influences mobility. Thus, it is important to correlate the city-specific characteristics to urban mobility [53]. Similarly, for accessibility surveys in congested urban cores, besides considering the goals mentioned in United Nations Sustainable Development Goals (hereafter, UN-SDG) it is also essential to identify "contextual" infrastructural indicators for Urban Mobility [54]. Amongst the city-specific features, Land Use is one of the most important factors. Litman (2016) argues that high density complemented by multiple activities has a manifold impact on the rate of accessibility; and consequently, walkability can be improved if travel distances are shorter. Litman further explains the different genres of accessibility based on the type of route; for example, 1) End of roadway, 2) Centre of Roadway, 3) Loop-type Road, 4) Crossroads, and 5) Grid patterns [55]. Scenario Analysis after classification of urban crossings helps in understanding pedestrian environments [56]. Along these lines, Evans (2009) holds that a specific "design index" for assessing inclusivity in a journey environment is necessary. The macro and micro elements (and attributes) of a street can be assessed through observational audit and strategic mapping [57].
Auditing in different parts of the same region to access the situation correctly shall foster a tailor-made/ site-specific recommendation for accessibility audit [58]. In similar lines, critical study of local policies before the assessment of pedestrian accessibility and bicycle accessibility shall be beneficial for imparting urban level accessibility [59]. However, the technically apt methodology to impart urban level accessibility is to develop a framework for "level of service" based on parameters (and their respective indicators) that influence Universal Mobility. The parameters (and their respective indicators) should be evaluated through an objective scoring/ ranking/ rating system, which in turn can be determined by a pilot survey. Besides these, identification of essential/ critical parameters (and their respective indicators) whose presence ensures Universal Mobility and viceversa, is also recommended [60].
Mobility in pedestrian areas (footpath) in core cities includes parameters like 1) Traffic factors (like, car parking), 2) Geometry/ Environmental/ Footpath factors (like, pavement conditions), and 3) Pedestrian Movement factors (like, pedestrian volume) [61]. United States Department of Health and Human Services (2005) proposes a Likert-scale based walkability audit tool (under Healthier Worksite Initiative) comprised of nine parameters, like: 1) Pedestrian Facilities, 2) Pedestrian Conflicts, 3) Crosswalks, 4) Maintenance, 5) Path Size, 6) Buffer, 7) Universal Accessibility, 8) Aesthetics, and 9) Shade. This walkability audit tool also segregates the nine parameters into three segments based on their importance in walkability [62]. Story and Mueller (2004) have established certain "performance measures" for supporting Universal Design through a stakeholder participatory approach. Along similar lines, the effectiveness of these "performance measures" relies heavily on the stakeholders" perspective of inclusiveness [63]. Scott (2014) indicates the need for explicit consideration of parameters for pedestrian-focussed Universal Mobility solutions, like: 1) Footpath Gradient, 2) Tactile Surface Ground Indicators (TGSIs), 3) Gratings, 4) Kerb Ramp, 5) Signage, and 6) Public Art. Scott also identifies indicators for each parameter in the form of "key design features"; for example: the indicators for parameter "Gradient" is "cross fall less than 1:40" [64]. Wieters (2016) identifies technology (like, Online Survey) as one of the tools in research involving walking habits in the built environment [65]. Mosca and Capolango (2018) explain that post accumulation of requisite data for understanding universal mobility, the evaluation methods can be categorised into three types of user needs, 1) Potential, 2) Actual, and 3) Actual/ Potential. Mosca and Capolango (2018) further state that the combination of the three aforesaid types might render better results [66]. The walkability of existing pedestrian walkways, which is an essential component of Inclusive society, is best evaluated using a multicriteria method [67]. Along similar lines, pedestrian access and mobility plan are suited for ensuring Universal Mobility. This plan is a product of Architectural Planning since it involves a research-based audit-fostered pedestrian route development [68]. Through urban street-level imagery, the urban environment can be understood from a human perspective [69]. Thus, the authors of this research have considered imagery as an important tool for this research.
Smart cities can enhance walkability for all by providing: 1) navigation applications, 2) environmental data in real-time, 3) Public Transport data in real-time, and 4) enhancing communication between pedestrians and city administration. In planning terms, the old and new cities demand different guidelines; especially in India, where the "Smart City" (urbanism propelled by Information, Communication and Technology or ICT) wave is seldom focussed on identifying the historic nature of the cities. Thus, to ensure peoplefriendly approaches in traditional organically developed compact cities, it is necessary to take into consideration the origin of the spaces [70]. However, the "Smart City" guidelines include the factors of physical accessibility in outdoor movement besides other technology-based inclusive features in urban environments [71]. In India, the recognized categories of "Persons with Disabilities" changed gradually from seven (in PwD Act, 1995) to five (in 2001 Census) to eight (in 2011 Census) to twenty-one (in 2016 RPwD Act). Hereafter, any urban development is supposed to be inclusive for the identified group as well. In spite of identifying accessibility as the major component of Smart Cities, no comprehensive contextual audit format for assessing Urban Mobility has not been considered [72]. Legislative support and Architectural planning are equally essential to ensure an Inclusive society [73]. In the Indian post-independence (in 1947) period, there have been repeated efforts to ensure an equitable social condition by including the needs of differently-abled and elderly. There have been several guidelines like -Policies, Acts, Rules, Regulations, Notifications, and Schemes, to facilitate the differently-abled people and elderly; especially in the field of Architecture, Civil Engineering, and Planning. However, these guidelines have not been able to bring about a radical change in the Universal Design paradigm of Urban India [74].  [75].
However, the realization of these guidelines at the Urban Level (especially old cores) has not taken place in India due to complex administrative issues. Thus, there is a need to prepare a specific research methodology to understand the aspect of Universal Mobility in the city cores of Urban India.
As an exercise for ideal/ inclusive streetscape study, the authors did a rapid baseline assessment of certain footpath stretches in Sapporo, Japan (Refer Figure 3: a to f). Japan is a country with a large number of elderly (28% of the total population) and 4.3% differently-abled citizens, considers a Universally Designed streetscape as a prerequisite to Urban development [76]. Mahapatra, Mori, and Nomura (2021) in their paper "Universal Mobility in Old Core Cities of India: People's Perception" used "Critical Instance" Case Study type research for similar genre of research, suggested that there is a need for framing a new assessment framework for assessing the scope of Universal Mobility in old Indian cities. In relation to this, research of this genre requires a specific approach towards the site context, and thus cannot be conducted using generic research methods (from the familiar methods of research design). The next section elaborates on the Research Design adopted for this paper. The research design has considered the context of the study area (as discussed in the "Historical Development of the Case Area" Section), the Literature Study (as discussed in this section), and previous research by authors.

Research Design
The hypothesis considered by the authors states that the poor walkability condition is a major hindrance towards transforming the core Indian cities into Universally Designed space, which is a necessity in 21 st -century inclusive urban scenarios. Along similar lines, the deteriorated mobility conditions pose a threat to people with functional and cognitive limitations, including elderly people. Furthermore, there is a need to frame a new assessment framework for Universal Mobility for these old Indian cities, since the usual (generic) factors of walkability have no/ negligible influence on the pedestrian volume in these areas. The inquiry mode for this research is "Structured". In Structured research methods, the analysis is dependent on the type of data collected.
Consequently, an "Infrastructural Conditions mapping" was conducted in the case area, which was further subdivided into thirty-two stretches. The "Infrastructural Conditions mapping" segment is composed of eighteen categorical variables. The categorical variables (considered as "Criteria" during survey and analysis hereafter) are: 1) Building Typology of Stretch, 2) Footpath Dimensions, 3) Temporary Encroachment, 4) Permanent Encroachment, 5) Bus Stop, 6) Metro Rail Entrance, 7) Railings, 8) Storm Water Drains, 9) Public Toilet, 10) Trash Bins, 11) Street Lights, 12) Flooring, 13) Manholes, 14) Kerb, 15) Pedestrian Crossing, 16) Street Furniture, 17) Safety and Security, and 18) Additional Inclusive Features. These Criteria are further subdivided into respective sub-criteria (fifty in total). These sub-criteria can be further grouped into two types of variables: Independent, and Dependent. As an example, for one of the categorical variables (criteria) "Public Toilets", the associated sub-criteria are: 1) Presence of Public Toilet, and 2) Functional Public Toilet. In this example, the "Presence of Public Toilet" is independent of any factor; however, "Functional" condition of the public toilet can be assessed if the public toilet is present at all. Thus, the sub-criterion "Presence of Public Toilet" is an independent variable, and "Functional Public Toilet" is a dependent variable.
The subsequent survey format for understanding "Infrastructural Conditions" (through primary observation) was framed based on these criteria and sub-criteria. Postsurvey, the observations were further analysed using a scoring pattern. The sub-criteria was scored based on their associated variable type (independent or dependent). The presence of a sub-criterion is scored as either "+0.50" if the associated variable is an Independent Variable. In similar lines, a sub-criterion is scored as "+0.25" if the associated variable is a Dependent Variable. Similarly, the absence of a sub-criteria is scored as "-0.50" for Independent Variables and "-0.25" for Dependent Variables respectively. Since each subcriterion is essential for a stretch to qualify as a Universally Designed space, the sub-criteria are given equal weightage, i.e. +0.50 for the independent variable and +0.25 for the dependent variable. Appendix 4 explicitly shows the Variables (Criteria and Sub-Criteria), Types of Variables (Independent/ Dependent), Scoring Logic, and the Individual Scores used in this research. For any study stretch surveyed using this framework, the consolidated highest score can be twenty (and subsequently, the lowest can be -20). It is to be noted that although all these variables are not equally important for pedestrian activity; however, negative impact of any one of them could lead to inadequate Universal Mobility standards.
Each of the thirty-two stretches in the delineated case area within Central Kolkata was surveyed based on the above methodological framework using the "Online Google Form" type Survey Format. The type of questionnaire is the "Dichotomous Close-ended" type. The Google Form is available online at https://forms.gle/EmTMDYvA34XZq4Hk9 (accessed on 23rd May 2021) and is shown in Appendix 5.

Survey and Findings
This section may be divided by subheadings. It should provide a concise and precise description of the experimental results, their interpretation, as well as the experimental conclusions that can be drawn. For mapping "Infrastructural Conditions" for this research, Field Surveys were conducted between 1st August 2020 and 2nd September 2020. The surveys were conducted with the help of some local people (students and professionals) who were acquainted with the surveyed study area. The details of local people who helped the authors are duly mentioned in the acknowledgement section. The recorded data from the study area (Central Kolkata, India) was eventually compiled and analysed in the Laboratory of Architectural Planning (Hokkaido University, Japan) between 14th December 2020 and 1st March 2021. Figure 4 indicates the locations selected for the survey using the variables considered. Table 1 shows the details of the locations and stretches illustrated in Figure 4.   Figure 4.

Corresponding Numbers
in Figure 4 Stretch Details Length (in m) Width (in m) [N.B.: The "width" refers to the predominant width that the footpath is having and is measured physically at different sections of the same footpath during the primary survey. The respective widths are measured physically on-site during the primary survey. The "length" refers to the measurement of the external kerb of the footpath that is connected to the adjacent road and is measured using satellite imagery.].
The elaborate observation and scoring of Criteria (and Sub-Criteria) with respect to each surveyed stretch is tabulated as an additional document to this paper. In relation to this, the findings are summarised hereafter.
Among the thirty-two stretches selected for the survey, 100% of them bear the presence of buildings having 'two or more' building uses within a single building. The building use ranges from: a) Residential, b) Educational, c) Institutional, d) Assembly, e) Business, f) Mercantile, g) Industrial, h) Storage, and g) Hazardous. In addition to this, heritage structures are present in 84.4% (27 nos.) of the stretch.
Based on the adjacent predominant "commercial/ mixed" land-use in the surveyed stretch, the ideal width of the footpath should have been 2500mm. Moreover, since the pedestrian stretches are adjacent to the buildings, a "Dead Width" of 500mm should be present over and above the 2500mm [77]. However, among the thirty-two surveyed stretches, 78.1% (25 nos.) of them had a width of less than 2500 mm. 65.6% (21 nos.) among the thirty-two surveyed stretches do not have an unobstructed width of 1800mm. However, there is an unobstructed clear height of 2200mm in 71.9% (23 nos.) of the surveyed stretch.
Unorganized Informal Vending is observed in 46.9% (17 nos.) of the thirty-two stretches that were surveyed. However, Informal vendors/ hawkers are away from the line of pedestrian flow in 18.8% (6 nos.) of the surveyed stretches. Beggar, and/or Homeless people, and/ or Child Labour are existent in 21.9% (7 nos.) of the entire surveyed stretch.
Places of religious interest are existent in 68.8% (22 nos.) of the surveyed stretches. The eminent ones are "Saint Francis Xavier" Church, "Firingi Kali Bari" Temple, "Sri Sri Ghanteshwar Mahadev" Temple, and "Carey Baptist" Church. 78.1% (25 nos.) of the surveyed stretch were encroached by existing establishments. In 21.9% (7 nos.) of the surveyed stretch, Communal Open Bath is present and functional.
Among the thirty-two surveyed stretches, public buses stop informally at 50% (16 nos.) during various times of the day. However, Bus Stop is present in only 3.1% (1 no.) and that one cannot be considered functional as per design standards. Railings along the surveyed stretches are existent in 40.6% (13 nos.) of the thirty-two surveyed stretches. Among the thirty-two surveyed stretches, at 15.6% (5 nos.) a thorough pedestrian guard rails (with minimum 1500mm height and clear visibility is existent. Among the surveyed thirty-two stretches, Storm Water Drains are present in 90.6% (29 nos.). Except in one stretch, Storm Water Drains are working at 87.50% (28 nos.).
Only one (3.13%) Public Toilet is present in the surveyed stretch, and it is in working condition.
Trash Bins are present in 12.5% (4 nos.) of the surveyed stretches. Except in one stretch, Trash Bins are working in 9.4% (3 nos.) stretches. These municipal garbage bins are away from the line of pedestrian flow in 12.5% (4 nos.) of the surveyed stretch.
Streetlights are present in all thirty-two surveyed stretches. Except for two stretches, Street Lights are working at 93.8% (30 nos.). In 93.8% (30 nos.) of the surveyed stretches, the electric poles are neither placed away from the pedestrian flow and nor demarcated with a tactile marking of a minimum of 600mm around the poles.
Satisfactory cross-fall satisfactory (i.e., <1:50) is existent in 62.5% (20 nos.) of the thirty-two surveyed stretches. In addition to this, tactile paving is not present in any of the surveyed stretches. 75% (24 nos.) among the thirty-two surveyed stretches do not have anti-skid/ matt finish tiles in the footpath and kerb.
Although Manholes are present in each of the thirty-two surveyed stretches. The 'drain type' manholes are flushed with the pavement surface in 87.5% (28 nos.). In 71.9% (23 nos.) of the thirty-two surveyed stretches, the 'grating' type manholes are sited away from the respective pedestrian walkway.
In 71.9% (23 nos.), Kerb alongside surveyed stretches is observed. Among the thirtytwo surveyed stretches, the Kerb is not at a height of more than 150mm from the road in 75% (24 nos.). Additionally, in 93.8% (30 nos.) of the surveyed stretches, the Kerb ramps present in the stretches neither have a minimum width of 1200mm width nor have tactile warning. In relation to this, a cornered Kerb radius of more than 6m is present in none of the thirty-two surveyed stretches.
'At-grade' pedestrian crossing (MID-BLOCK crossing) at intersections along the walkway is present in all the thirty-two surveyed stretches since the delineation of survey stretches was made by fragmenting the footpath from one end of a street's entrance till the entrance of the next street. However, Signalized Crossings are existent in 50% (16 nos.) of the thirty-two surveyed stretches. Except in one stretch, Signalized Stretches are working at 46.89% (15 nos.). Audio Signals are not present in 96.9% (31 nos.) of the surveyed stretches.
In 34.4% (11 nos.) of the surveyed stretches, street furniture is present. Additionally, in 25% (8 nos.) of the stretches, the street furniture has knee clearance of a minimum of 700mm and wheelchair space of 1000mm.
In similar lines, the stretches neither have Fire Hydrant, nor Security Cameras. In all the thirty-two surveyed stretches, additional inclusive features like Street Signage, Bicycle Track, and Bicycle Track are absent. However, Street Art is present in one (3.1%) of the surveyed stretch.

Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 24 December 2021
This section of the research starts with tabulating "Total achieved score of sub-criteria across all thirty-two surveyed stretches" divided by "Maximum Achievable Score of each sub-criterion", as shown in Figure 13. Based on the aforementioned figure (Figure 13), the percentage score of the fifty subcriterion can be segregated into three domains-Positive, Neutral or zero, and Negative. Out of fifty sub-criterion, 68% (34 nos.) are in the negative domain suggesting weak infrastructural conditions in the case area. In addition to this as much as nine (18%) of the subcriteria bears negative 100% score. Furthermore, in two (4%), the score is zero, suggesting the gap in ideal accessibility conditions. The remaining (28% or 14 nos.) are in the positive domain. Among the fourteen sub-criterion in positive domain, only two (4%) are having positive 100% presence.  In addition to this, based on the aforesaid observations, the thirty-two surveyed stretches were scored as per the methodology elaborated in Appendix 4. As explained within Segment 4 of this paper and in Appendix 4, for any study stretch surveyed using the framework used for this research, the consolidated highest score can be twenty (and subsequently, the lowest can be -20). In relation to this, none of the thirty-two surveyed stretches in this research have a positive score. Individual score for each of the thirty-two stretches in response to the eighteen criteria (and respective sub-criteria) is mentioned in Appendix 6.
Along these lines, the inferences from the survey prove that the case area has considerably weak pedestrian conditions. Thus, the hypothesis considered for this research holds true. The approach towards improving the conditions (by city authorities) can be prioritised in two patterns: 1) Precinct based approach (on the basis of the percentage score of the sub-criterion across all the surveyed stretches): The sub-criterion having negative score in negative percentage score requires prioritized attention in terms of infrastructural intervention, followed by the sub-criterion bearing zero percentage score and the ones bearing negative percentage score respectively. So, within a particular precinct, each sub-criterion shall be developed in a sequential order. However, pertaining to the contextual constraints of old cities (like unchangeable footpath widths, or occasional street vendors), the aim of city authorities should be to reach as much score as possible. 2) Case-Based approach (on the basis of score of the individual surveyed stretch evaluated using the research framework): The stretches with lowest score can be prioritized while taking up infrastructural assignments. Each stretch can be improved as much as possible (based on the specific context) before taking up the next stretch.

Scope for further research
Based on the findings from this research, the authors recommend an Accessibility Audit format for assessing the degree of accessibility in the walkability conditions of old core cities of India. Keeping coherence with the audit format used in this research for mapping "Infrastructural Conditions", a "weightage" is added to the survey format for further study in old core Indian cities. Out of a total 100% weightage, 97.5% is distributed across the eighteen criteria (including the fifty sub-criteria) and an additional 2.5% is kept flexible for contextual factors (like topography, harsh climate, and likewise). In the context of old Indian cities, the contextual factors might refer to potholes, etc. Thus, while using the survey format in different old Indian cities (other than the case area of Kolkata), the contextual factor shall vary.
It is to be noted that the Mean value of the respective sub-criteria is considered as the percentage score for a Criterion. The weightage allocation is based on the percentage score of each Criterion (as shown in Figure 13), where Criteria with: (1) 0 to 50% is allocated 20% weightage, (2) 50% to 100% is allocated 10% weightage, (3) -50% to 0 is allocated 5% weightage, and (4) -100 to -50% is allocated 2.5% weightage. The logic used in allocating the weightage is: criterion with more percentage is predominant in the old core areas, and conversely, criterion with least (or negative) percentage is more suited for an "ideal" accessibility condition. The term "ideal" represents the conditions referred to in Indian guidelines (proposed by likes of Indian Road Congress) as best suited for pedestrian comfort. Figure 14 shows the proposed accessibility audit format with associated weightage for each criterion.
[Continued on next page] The authors propose the following model ( Figure 15) for further research. In relation to Figure 15, Stage 01 to Stage 03 has been covered in this paper; however, the authors suggest that Stage 04 might strengthen the formation of an Accessibility Audit format for old cities in India. The authors further elaborate on Stage 04: Similarly, the feedback of the intended user group for the Universal Design solution needs a heterogeneous treatment for research analysis [82]. The "Cognitive Factors" segment is composed of two parts: Cognitive Mapping, and subsequently three continuous variables: 1) Noise (Sound Intensity measured in Decibel), 2) Light Intensity (measured in Lux), and 3) Thermal Comfort (Temperature measured in degree Centigrade).
The Cognitive mapping can help in understanding the convenience to walk by assessing the travel distance and time. As an initiation, the authors have started to conduct surveys in Hokkaido University campus involving a prosthetic suit which induces a scenario of elderly physical condition when worn by individuals. The individuals are asked to walk a certain distance with and without the prosthetic suit during same time on a single day/ night. Figure 16 shows some instances from the research. For assessing the continuous variables (Noise, Light Intensity, and Thermal Comfort), the type of questionnaire to be used for this survey is Structured Open-Ended. During the survey, multiple measurements (across different seasons, and different times of the day) should be taken for ensuring Reliability Ethics. A suggestive "Online Google Form" used for this survey is available online at https://forms.gle/iRRS9ZMQu9GY2yt98 (accessed on 26th May 2021). Additionally, collaborative (authors and end-users) cognitive maps can be useful.

Traffic Volume Count:
The "Traffic Volume Count" is composed of an independent variable: Number of Pedestrians during peak hour. Successive measurements (across different seasons, different times of the day, different days of the week, and during festivals) must be taken for ensuring Reliability Ethics.
Furthermore, these two factors "Cognitive Factors" and "Traffic Volume Count" can be related to the Accessibility Score in walkability scenarios (which has been furnished in this paper).

Impact of this research
Indian cities have multiplicity in administrative settings and an inherently complex Social Model of disability. However, from the perspective of APR, the technical aspect of Accessibility can be addressed suitably. After understanding the need of people with functional limitations (from the Medical Model) and the appropriateness of infrastructure requirements (from the Social Model), the Technical Model can be proposed as shown in Figure 17. Responsibility for ensuring Accessibility in Old Core Cities allocated to Specific departments in the Urban/ Municipal administrative setting shall enhance the chances of making citizen-friendly pedestrian streetscape. This process, in turn, shall also ensure the realization of UN-SDG Number 11: Sustainable Cities and Communities.
The famous statement by Frank Chimero "People ignore design that ignores People" holds true for describing the case area in this research. The historically rich core of Kolkata is in the decaying stage since the case area is less suitable for human mobility (at pedestrian level). Furthermore, Architectural Planning Research (APR) might be an important tool to approach accessibility-related assessments or interventions, in old core Indian cities.
The authors are part of the "Laboratory of Architectural Planning", Hokkaido University, Japan. The "Laboratory of Architectural Planning" prioritizes exploring next-generation planning theory that contributes to global well-being. In relation to this, some objectives of this laboratory are noteworthy: Objective 2.1: Environmental Design that realizes safe and comfortable going out for the physically vulnerable, and Objective 4.1: Daily movement of people and spatial perception/ cognition. In previous publications from the "Laboratory of Architectural Planning", the different typologies of walkability in Asian context have been investigated from multiple perspectives [78]; including local mixed-use streets [79]. Especially, the re-development strategy of old streets in the Asian context has been contextually evaluated in this laboratory [80] [81]. Thus, the authors suggest scopes for further research in the same domain in coherence with their affiliated laboratory.
Finally, the authors state that the theoretical, ideological, and methodological learnings from this paper can be referred to by researchers for further investigation on accessibility issues in old core Indian cities.    Maximum Total Score +20 -20

Appendix 5
Survey Format for assessing Infrastructural Conditions in the case area.
Individual score for each of the thirty-two stretches in response to the eighteen criteria Graph showing the scores of 32 sub-stretches