As a concept, sustainability depends upon the support of the three pillars of economic growth, environmental protection, and social equity. Nevertheless, progress towards developing socially equitable and inclusive solutions within the built environment is slow. New methods could improve inclusivity. The five-stage Service Design (SD) method, used in the financial services industry (observe, synthetise, new idea, refine, and implement), was transferred to the design of the built environment. Case 2 represents a new paradigm for an inclusive underground station. Now case 2 is operational, this new post-occupancy study used a participant observation method to co-experience inclusivity, in situ, at two stations. Critical customer ‘touchpoints’ of the passenger’s journey reviewed are, arriving at the station entrance, entering, ticketing, waiting, boarding, riding the train, alighting, and continuing. Finding, waiting, and taking the lifts. Video recordings taken result in a long descriptive analysis that triangulates with literature. To provide accessibility for everyone, stations need not be more costly or larger. It is practical to transfer the SD approach to the built environment context during the early design stage. Co-experiencing inclusivity with a designer and users within a building is a beneficial and inspiring learning opportunity. These are significant original contributions of this work.
1. Introduction
The Brundtland Commission defines sustainability as ‘meeting the needs of the present without compromising the ability of future generations to meet their own needs’ WCED (1987). The sustainability concept requires the support of the three pillars of economic growth, environmental protection, and social equity (WCED, 1987: 35). The UN supports sustainability through Sustainable Development Goals (SDGs). Accessible transport, required by legislation, relates to UN SDG No 11 (Make cities and human settlements inclusive, safe, resilient, and sustainable). To address sustainability, the railway industry grows the economy, protects the environment by reducing carbon dioxide (CO2) emissions, and connects people to places of employment, leisure, and housing (DfT, 2019).
Vitals for social equity are accessible public buildings and urban areas that deliver products and services to people (Clarkson and Coleman, 2015: 236). However, the experience of step-free access for disabled people travelling within London's public transport network is poor (Boyle, 2009: 20). Implications of poor accessibility include a weaker ‘transport chain’, or the door-to-door passenger journey (From Exclusion to Inclusion by the Disability Rights Task Force (DRTF), 1999 cited in Bichard, 2014: 90). Older people and irregular travellers lack confidence compared with younger travellers (Marsden et al., 2008). Step-free access from street level to the platform to the train is a relatively new phenomenon.1 To improve inclusivity and service within the built environment, Harding’s (2020a) review recommends the Service Design (SD) methodology is transferred to a design study of an underground station (Harding, 2020b). That new idea develops in a case study using agent-based modelling (ABM) to deduce what rival case affords an inclusive service. Case 2 reflects Martens’s (2018: 122) definition of inclusive design (ID) that affords access for everyone, and demonstrated an efficient, inclusive, and usable design without increasing costs or size of the station (Harding, 2019). Ten new underground stations implemented the Case 2 configuration, with minor variations, and serve the operational Red Line LRT in Tel Aviv.
This post-occupancy study probes, in situ, whether the case 2 design delivers the anticipated benefits for inclusion and service. It reuses a reliable auto-ethnographic method to review two stations in London serving the Jubilee Line (Harding et al., 2016) and the Elizabeth Line (Harding, 2024a; Harding, 2024b), creating a new nuanced understanding of the co-experience of inclusivity within a case 2 station.
2. Delivering an inclusive service in underground stations
This literature review reveals the themes relating to the inclusive service experience within busy buildings, and the features of circulation spaces that impact movement. The aim is to provide a cross-disciplinary synthesis of the state of the art. Literature searches apply key terms, ‘service design’, ‘inclusivity’ and ‘building circulation’, both singularly and in combination. Articles reviewed were empirical studies and literature reviews relating to buildings, at one or more SD stage (see Figure 1).
2.1 Service design applied to complex buildings
Service Design is all about making the service you deliver useful, usable, efficient, effective and desirable. (Design Council, 2010).
Shostack (1984) identifies SD as a way of thinking about the services one uses. These may provide an exemplary experience, fail to deliver, or fall between both. Services include enjoying a drink in a favourite café, taking a train journey from home to work, hiring a taxi, or employing a consultant to design a new building. Services are neither a physical object nor a product. They are an experience. A designer’s report may look like a product, comprising paper and ink; nevertheless, the client is buying skill and experience. She concludes: ‘Better service design provides the key to market success, and more important, to growth’. And as a country ‘… moves towards a service economy, companies that gain control over the design and management process will be the companies that survive and prosper’. Gradually, the SD concept, transfers from the financial industry to other service industries, including transportation. Turner argues that SD can advance inclusive design where, in the case of Heathrow Airport Terminal Five design, ‘if you make things clear for the disabled and old, you make things even easier for everyone else and if people find the airport easy to use, they will be willing to repeat the experience’ (Turner, 2003: 279–284). IDEO, an SD and product design company, developed the ‘passenger journey’ concept for Amtrak (the national railway operator in the USA) to deliver a seamless passenger experience for a proposed high-speed train service. Critical ‘customer touch points’ that impact the service experience include where the passenger seamlessly obtains information, plans the journey, travels to the station, enters the station, buys tickets, waits, boards the train, travels on the train, alights, and continues the journey (see Figure 2) (Bhavnani and Sosa, 2008). However, Tzortzopoulos et al.’s (2009) literature review identifies a few attempts to link healthcare service experience and building design. They recommend the development of a ‘holistic and integrated theoretical body of knowledge that will offer appropriate guidance [to] support improvements in practice’ (45). Consequently, to develop that theoretical framework, Harding’s (2020a) literature review of inclusive transport building research recommends that the SD methodology is examined as an example of a ‘next, next generation’ method, ‘more relevant to architecture and planning rather than engineering and industrial design’ (Rittel and Webber (1973) cited in Cross, 2007: 1).
2.2 Co-experiencing inclusivity interactions, in situ within busy buildings
To check compliance with accessibility legislation, Ormerod (2005) describes how access audits, completed post-occupancy, often result in a tick-box exercise. However, once occupied, it is costly and disruptive to modify the design of a building. Nor is it that a single person or even a small team will have a comprehensive understanding of all disabilities. And while a large team could reveal issues, it would be unfeasible for clients. To develop insights about critical inclusivity interactions within underground ‘Tube’ stations, Harding’s (2011, 2025) questionnaire surveyed ‘tube’ users experiences at stations. Participants were train commuters comprising 47 working-age people, 34 male and 13 female and a mixture of age groups. Their experiences, elicited by using a five-point Likert-scale questionnaire, indicate the following concerns: Comfort: Half have difficulty travelling with heavy bags, and almost a quarter never use lifts. When using a lift, a third of people experience excessive journeys. Over a third of people do not use seats when tired, and half feel exhausted after travelling on the Tube. Over a third of people avoid travel owing to the excessive cost. On the other hand, most participants can walk up or down stairs comfortably and use lifts. Nevertheless, most like to use escalators. Over half have used lifts, and a lack of, poorly located, or small lifts may explain why a quarter never use them, and when they do use them, a third experience excessive journey time. Security: Most participants feel secure at crowded tube stations when waiting for lifts alone and have no experience of crime on the Tube. On the other hand, over half experience anti-social behaviour, and few have experienced crime. Most experience fear of crime when alone at night at empty stations, and in crowded stations. Some feel insecure in vulnerable situations and dead-end corridors. Almost half experience dark or poorly lit stations. Gentleness: Participants help disabled people and people with prams or heavy luggage. Nevertheless, station environments are noisy with unclear announcements, have excessive changes in levels, are confusing and create disorientating experiences. Participants do get lost and fear losing members of their travelling party. Confidence: Most participants are confident they can find their way inside stations; the Tube can provide access to most places they want to go, and they can find alternative routes when the Tube is not working. Just over a third confidently talk to strangers. On the other hand, almost a third rely upon the Tube and few have difficulty seeing signs and finding their way, while a third do not talk to strangers. Awareness: Most participants recognise disabled people who require help. Almost half would like inclusive design training, whereas a quarter do not.
Table 1 summarises the findings according to age and gender of participants and five critical themes. Surprising similarities: All gender and age groups have satisfactory experiences of confidence. The group with the best experiences of comfort, security, and confidence are the over 55-year-old participants. Surprising differences: Everyone has an unsatisfactory experience of gentleness. All groups, apart from men and over-55-year-olds, have a middling to unsatisfactory security experience. In contrast, the middle-aged group has worse comfort and security experiences, and the youngest age group has worse experiences overall. Men’s experiences are slightly better than women’s. This suggests that comfort, security, gentleness, and confidence are satisfactory proxies for inclusivity. When the questionnaire survey was completed, 24% of Londoners had a long-standing illness or impairment (TfL, 2012: 17). It is surprising that no participants declared a disability in the survey. In explanation, a negative reply to this question is common in surveys owing to disabled people having trouble travelling, gaining and keeping a job, and consequently are silent about their disability (Payling, 2003: 395). Lack of disability data is a limitation; nevertheless, the data showed that age and gender are considerable factors that contribute to the inclusivity literature.
Watson et al.’s (2016) literature review of over 200 publications considers how different building types are experienced in post-occupancy research. The top five building types were housing, workplaces, healthcare, education, and the retail-service sector. There is limited literature relating to railway stations. Busy workplace, healthcare, and educational buildings provided a low level of autonomy for users to modify their environments. Their review identifies significant potential benefits when a building design develops with user outcomes in mind. For example, health, well-being, behaviour, and performance. To improve understanding of user interactions within buildings, they recommend that a nuanced in situ research approach is necessary. Zallio and Clarkson (2022) reviewed several post-occupancy evaluation methods. They developed a web-based audit that considers inclusion, diversity, equity, and accessibility in the built environment. However, their method is not in situ, and excludes the desirability, efficiency, and usability aims of SD required in this study.
Battarbee (2004) argues that a co-experience in situ method will inspire designers. Designers need to ‘co-experience’ the physical and emotional interactions with users in the same social context. By ‘leaving the design office and becoming briefly immersed in the lives, environments, attitudes, experiences, and dreams of the future users’. Similarly, Imrie and Luck (2014) argue that designers internalise the requirements of the user. To sensitise and inspire designers, Harding et al. (2016) developed and implemented an in situ autoethnographic method. This method enables the designer to co-experience the socio-material interactions of passengers’ inclusivity when moving within crowded, complex horizontal and vertical circulation systems within underground stations. Their methodology was replicated in two post-occupancy studies in London, an older Jubilee Line station (Harding, 2024c), and a new mined Elizabeth Line station (Harding, 2024a, 2024b). These studies discuss how auto-ethnography contributes to the broader methodological debate about how to explore and consider inclusive design issues from a user’s perspective, and in the context of empathetic design. It is an appropriate method for researchers and designers to co-experience inclusivity with commuters within crowded underground stations.
2.3 Pedestrian movement theory and inclusivity
Fruin (1971) develops canonical pedestrian movement Level of Service (LOS) theory to analyse crowd movement within the constraints of street pavements, concourses, underground stations, and transport termini. He innovatively transfers the LOS theory from the field of highway design to the design of public circulation areas in buildings and pavements used by pedestrians. A high LOS (A-C) describes a free-flowing space where a rapid change of direction is possible. Whereas a low LOS (E-F) describes a highly congested density level where it is difficult to change direction (Fruin, 1971: 71). However, it is alarming that there is a limited discussion of the use of elevators in stations. His guidance book is influential and is a reference for designers and authorities worldwide to validate station designs (Network Rail, 2011: 12).
Goldsmith, an influential scholar (1976: 401 item 77200), claims ‘it was not essential’ to make underground stations accessible for wheelchair users, owing to excessive costs (US$10m for lifts on the BART in San Francisco, and US$44–60 m for lifts on the Washington DC metro built in 1971) (60 para. 1411). Goldsmith’s views were influential. His books formed the basis of the British Standard Code of Practice on Access for the Disabled to Buildings (CP96) in 1967, later revised to BS5810 (1979) and then Part M of the Building Regulations in 1987 (Coleman et al., 2003). Fruin (1992) provides a tutorial paper concluding that ‘[e]elevators have had limited application in transit stations, except for vertical movement of physically impaired persons’.
Harding’s (2011) questionnaire survey shows that people find it tiring, difficult, and slow to move vertically and move long distances quickly. He defines this difficulty of moving vertically as Vertical Severance (VS) as the ‘… separation from ground level to the platform that creates spatial mobility and socio-economic concerns for individuals. VS results in less diversity and more exclusivity within transport modes and the cities they serve’ (Harding, 2013: 13). Harding et al.’s (2016) review of the passenger’s journey from arriving at the platform, seeking the single, small lift located at the end of a crowded platform, then travelling to the concourse level at a busy Jubilee Line station. Although a single small lift achieved disability legislation, it does not meet service expectations for usability, efficiency, desirability, or inclusivity nowadays, and is difficult and expensive to change once a station is operational.
Moreover, in his literature review Harding (2020a) claims Fruin misses a critical difference when he transfers evaluation methods from highway design theory to pedestrian movement theory (Highway Capacity Manual, Highway Research Board, Special Report 87, Washington, D.C. (1965) cited by Fruin, 1971: 71). The critical difference is that people are not motor vehicles. While a vehicle may easily move up or down a steep hill, pedestrians experience difficulty when moving vertically such as in deep stations, or long distances owing to strength, age, ability, disability, and other factors (Harding, 2025). To deliver an inclusive service for everyone who may need access (Martens, 2018), older canonical theory (Fruin, 1971, 1992) and views of what affordances are necessary in stations, and for whom (Goldsmith, 1976), requires revision.
2.4 New ideas to solve ‘wicked’ inclusivity theory
‘Wicked’ problems cannot be solved by traditional scientific and engineering methods (Cross, 1982). They include what design method, universal (UD) or inclusive design (UD), would produce a more inclusive service (Martens, 2018). And knowing who, and how many people require help VS (Harding, 2013). Harding (2018) research proposal identifies a new way to use ABM, to research inclusivity within the circulation systems of busy buildings. He proposes to use ABM, as a trusted industry research instrument (Network Rail, 2011), to evaluate the impact of pedestrian congestion using the LOS concept (Fruin, 1971). He proposes a study using a quantitative hypothetic-deductive method (Popper, 1972) to evaluate two rival schemes. Case 1 has four escalators, a stair, and one lift and is an example of ‘first generation’ design methods and UD aims underpinned by the social model of disability discourse and canonical theory (Fruin, 1971, 1992). Case 2 was based on a new idea to address the issue of vertical movement (VS) as a ‘pain point within the passenger journey’ (see Figure 3). “… 0.1) Accept claims that well-designed lifts are beneficial to almost all individuals consequently develop designs with more and faster lifts (Maynard, 2007). 2) Consider other property types that solved VS, for example, Heathrow Terminal 5 which provides many large lifts to serve passengers carrying luggage (Turner, 2003)… 3) Consider [either] omitting or provid[ing] fewer spatially inefficient escalators to deeper stations, or where passenger exit and entrance numbers are relatively low, provide more space for lifts. [4] Further research could probe how different circulation choices could satisfy either [case 1] 10% or [case 2]25% of overall passenger numbers who may wish to use a lift at stations” (Harding, 2013: 11). Case 2 has three escalators and four large lifts and provides a potential paradigm shift towards a new inclusive underground station, developed upon ID aims underpinned by socio-material interactional discourses (Figure 4). Entrances connect to an ‘active street’ (Figure 5) that contains seating, ticketing, and information adjacent to the entry to the paid area. The study concludes that a future study analyses rival cases to compare inclusivity, and VS within congested virtual spaces using ABM.
2.5 Hypothetical-deductive methods solve ‘wicked’ inclusivity theory
Harding’s (2018) research proposal is implemented in Harding’s (2019) quantitative study to compare two rival circulation cases within a ‘digital twin’ of an underground train station. ABM is used to compare LOS ‘heatmaps’ as a proxy for inclusivity. While both cases use the same input data, including passenger quantities, train arrival, and departure times, the results are surprisingly different. Case 1 produced unsatisfactory results for inclusivity and service at both platform and concourse levels owing to significant crowding (Figure 4). On the other hand, Case 2 increases LOS and inclusivity throughout the station, and within the lifts by fivefold. Case 2 circulation design allows users to use three escalators and four lifts to disperse along the platform and concourse (Figure 4). Case 2 is based on ID discourses to provide access for everyone (Martens, 2018: 122). It provides a new exemplar of a busy, inclusive urban underground station design that does not increase the overall cost or size of the station, in theory. Case 2 is a potential giant step in inclusivity and service, where 25% of passengers could chose to travel in large lifts. And the path less travelled to the lift affords a similar LOS as the path well-travelled to the escalators. Subsequently, Case 2 implemented at ten new underground stations with minor variations serving the recently opened Red Line in Tel Aviv.
2.6 Next steps: probing research questions in a post-occupancy study
Now that Case 2 is operational, this study explores the questions, what can one learn about the post-occupancy inclusivity and service co-experience in situ when using lifts for vertical circulation, and at each customer touchpoint along the passenger journey?
3. Methodology: a post-occupancy auto-ethnographic case study
The methodology used is replicated from similar studies in similar contexts (Harding et al., 2016; Harding, 2024c, 2024b) that produced reliable qualitative, nuanced, in situ, post-occupancy, co-experience results. Key differences are that case 2 stations are novel. And they are located in Tel Aviv, where the author also works, providing an opportunity to use and compare differences when using the methodology outside of London.
A case study design is applicable because they can provide compelling and actionable insights that enable change (Flyvbjerg, 2006). Uses include comparing and contrasting rival theories (Yin, 1993: 112–113). Fields include education (Yin, 1993) and infrastructure management research (Flyvbjerg, 2014). A good research design will advance knowledge and provide sufficient detail from fieldwork that is replicable, rigorous, and timely (Yin, 1993). Trustworthy case study designs can be quantitative or qualitative and require construct validity, internal validity, external validity, and reliability (Yin, 1984/1989, pp. 40–45 cited in Yin, 1993: 39). Construct validity is important for assessing generalisability. Internal validity is important to ensure that the design and execution of the study are free from bias. External validity is the extent to which the conclusions are generalisable to a wider population. Reliability is the extent to which the responses are stable. Table 2 summarises this case study’s key activities and validity requirements.
3.1 Observation stage
To address construct validity and generalisability, John is appointed as the participant observer. He is the research instrument owing to his ‘lived’ experiences as both an ‘insider’ (passenger and commuter) and ‘outsider’ (as researcher, designer, reviewer, or client). Buzard (1997: 103) summarises that the aim of the auto-ethnographer is to study a society or culture by observing one’s experience, from the inside, then working outwards as a researcher. That critical distance is essential to appreciate wider meanings that can be generalised.
John’s insider ‘lived experiences’ include frequent commuting in London by train, bus, and cycle, either alone or with family members who sometimes require assistance with heavy luggage, wheelchairs, and prams. This gives him the experience of travelling with less mobile people than himself. One has vivid memories of pain and discomfort and a lived experience of disability, temporarily needing a wheelchair, owing to having a spinal disc prolapse. Recently, he received an ADHD diagnosis. Kalanthroff et al. (2013) describe in their study of spatial processing in adults with ADHD, who comprise ≈5% of the child and 4% of the adult population, that adults with ADHD have lower global processing ability than the control group and that increasing alertness could improve global processing. Poor alertness is a characteristic of most ADHD adults, and poor alertness can be the cause of reduced global processing abilities. Global processing is similar to not being able to see the wood for the trees, i.e. having a bias towards seeing the detail but not seeing the ‘big picture’. That can also account for poor social and facial reading skills, ongoing patterns of inattention and/or hyperactivity-impulsivity that can interfere with functioning, and symptoms of ADHD. For example, John has experience of being alarmed and losing his balance when suddenly being aware of the ‘big picture’ when descending or ascending within a large escalator grouping, in a complex station or airport. Mastrodonato et al. (2016) recommend that providing more space and time for pausing, or ‘pause points’, to see ‘the big picture’ before moving to the next step of the passenger journey, can provide a clue to direction and is useful for reorientation. These memories and experiences provide John’s ‘lived experience’ travelling with children and prams, with an elderly parent, carrying bags and luggage. Now as an older person with minor disabilities, he has increased empathy to how people may feel excluded, easily disoriented, and vulnerable within the built environment and in busy stations.
John’s outsider ‘lived experience’ includes over 30 years of experience as an architect and urban designer. John works on multi-billion-pound programmes worldwide for clients, authorities, designers, contractors, operators, and maintainers. He specialises in the design, construction, operation, and maintenance of transport buildings in cities worldwide, including Dublin, London, Sydney, Tel Aviv, Istanbul, Abu Dhabi, Taipei, Taichung, Kuala Lumpur, and Singapore. Although limited by his particular male and age viewpoint, ‘working outwards’ has provided him with an opportunity to gain generalisable insights and reflexive co-experiences that have benefited his transport building design and research praxis.
3.2 Data collection and analysis
John completed AE surveys on journeys to and from the office at various times of day, weather, and seasons. He collects video data on the camera’s removable disk and copies data onto a portable hard disk. John is tall at 1.85 m and, from his eye height, will be able to see above fellow passengers and experience less obstruction. To collect data without causing alarm, he wore a discreet chest-mounted video camera. The lens was ≈1.4 m above ground level and at an eye height equivalent to a shorter 1.55 m tall person.
To address internal validity and reduce risks from bias, this research adapts Crichton and Childs (2005) data collection and analysis technique that preserves the original voices of the participants, by keeping the data intact until it is ready for transcription. They overcome problems in collecting, storing, and analysing substantial amounts of ethnographic data by ‘clipping’ audio files. Then, coding the data and deciphering patterns and trends.
Harding et al. (2016) and Harding’s (2024a, 2024c) post-occupancy studies adopted their approach, except for the following. Instead of audio data, video objectively captured people’s movement within the circulation along the passenger journey through the station. However, screen-captures of video produced low-resolution images. To increase the resolution, satisfactory for publication, an artificial intelligence photo-editing tool enhanced the images with insignificant data loss, and faces of participants blurred for privacy. Uploading the data to a website allows other researchers and analysts to develop alternative viewpoints and to contribute to the discourse (Harding, 2024a).
3.3 Writing up results
To address internal validity and risks of bias, a ‘thick description’ comprising words reports the critical observational details of human activities and experiences within a natural setting (Creswell, 1994) and explicates the differences, inconsistencies, difficulties, and challenges, at each customer touchpoint, according to the co-experience of the participant observer and user interactions. Explication ‘unfolds’ the experience by ‘looking for surprising similarities between things that are very different’ or ‘surprising differences between very similar things’ (Stainton-Rogers, 2006: 87). This abductive thinking develops hypothesis from experience (Peirce, 1955: 150), and is a common approach in SD research (Vink and Koskela-Huotari, 2022).
3.4 Discussion
To address external transferability and the extent to which results are generalisable, inputs from empirical observations are related to existing theory and literature. Theoretical relationships and hypothesises that are generalisable and triangulate with multiple sources of information are developed from observations (Yin, 1984/1989, p. 23 cited in Yin, 1993: 40). Sharing video data enables other analysts or groups to consider different experiences according to age, gender, and disability who may use the same data and develop alternative analysis to contribute to the discourse. Conclusion: To address reliability and the extent to which results are stable, the conclusion summarises the discussion and contributions.
4. Case study
Next, this case study explicates the participant observer experience within two of the ten new underground case 2 stations (Figures 6(a) and 6(b)). The visit occurred on 9 January 2025 during the evening peak ‘rush hour’ between 5 and 6 p.m. Approximately 16 months after service operation on 18 August 2023. The Red Line is a 24 km long Light Rapid Transit (LRT) that connects the northern, central, and southern municipalities of the Tel Aviv Metropolitan Area (TAMA). The LRT runs at grade level with 24 stops serving northern and southern municipalities. It then descends underground through the centre and serves ten stations a kilometre apart. Platforms are 80 m long. The train capacity is 450 passengers. The following ‘thick descriptions’ explicate the user experience at each of the critical customer ‘touch points’ along the passenger journey. These ‘touch points’ include arriving at the station, entering, ticketing, waiting, boarding, riding, alighting, and continuing, which are all critical stages that may impact the efficiency, confidence, and experience of the user.
4.1 Ben Gurion station
Arriving at street level near a major road junction, the station is difficult to find (Figure 7). One can see people moving in the vicinity of the entrance. Tall white walls and vent shafts block the view of the entrance. The entrance, inadequately signed, is not obvious within a busy urban streetscape. An angled shading canopy marks the entrance, and one can see the escalators and the lift (Figure 8). Several people enter the lift as it descends. The lift buttons, marked 0 and −1, give a clue to the destination. A panel to an electrical cabinet is missing in the lift shaft, which is visible because it is a fully glazed lift and lift shaft. Everything is on show in a glazed lift.
Taking the lift to the concourse, the doors open and one moves to the threshold, where sliding doors operate to let one enter (Figure 6(a)). Another set of doors is visible, fire doors on hold-open devices, before reaching the concourse (Figure 9). The concourse (Figure 10) is designed as an ‘active street’ intended to contain the ticketing and information required to support the passenger journey and to connect all the entrances to the ticket gates to the paid area (Harding, 2019). The ticket gates separate the unpaid from the paid street. Alongside the street are ticket machines, vending machines, water fountains, information boards, and seats. One sits on the bench seat to observe the concourse and people watch.
The impression is of a bright and colourful space, more like a shopping centre or airport. One feels comfortable, confident, and secure, sitting, lingering, and watching as if waiting at a public square or street. People watching and lingering is an enjoyable experience. People are moving calmly, within a satisfactory level of service in both the paid and unpaid streets, in opposite directions without conflict. Although people are reading phones while they walk, there is no bumping, pushing, or confusion. Everyone seems at ease and peaceful, calm, chatting without rushing. Lighting is located on the walls and ceilings, and is bright; nevertheless, the lighting does not glare uncomfortably. The acoustic space is not too noisy or echoic. Bright LED panel lights, without glare, are located above the ticket gates, consistent at all ten stations. These perform as intended and suggest that passengers move towards the light, ‘the light at the end of the tunnel’, showing the exit.
Moving through the gateline to the paid area, the journey to the platform continues to the lift. The lift is ready to board without waiting (Figure 11). It is nevertheless an attractive place to linger for a lift, with good lighting in a public circulation area. One feels safe waiting. Public toilets are to the left of the lifts along the paid ‘street’. There is no seating by the lift. Nevertheless, waiting time is negligible with four large lifts serving the platform. Seating is available nearby in the ‘paid’ street, too. Warm orange and matt grey walls complement each other, creating a generous feeling of desirability. Entering the glass-sided lift, one descends to the platform (Figure 12). One can see outwards to the concourse and platform as the lift descends, similar to the entrance lift. No surprises. This adds to the feeling of confidence, comfort, gentleness, and security.
Arriving at the platform, one can see many people waiting. The lift and escalators (Figure 13) are located close by. The SD aims were to improve convenience and certainty for passengers (Harding, 2019) by concentrating both lifts and escalators in the same space, within the field of vision using the ‘group vertical circulation’ strategy. This approach performs satisfactorily owing to people are waiting, boarding, and alighting from the lifts. Ben Gurion is due to be one of the busiest stations on the Red Line and will become busier once more LRT and future planned metro lines open for service in the next decade(s). People appear calm and comfortable waiting for the train within the bright and colourful platform space.
The next train arrives, and passengers alight. Not being a Hebrew reader, one finds it impossible to read the active signage and know which train to board, in which direction and at what time. Passengers wait without pushing until there is space to board the crowded train. There is adequate space to board and alight without sudden pushing (Figure 14). Riding on a crowded train (Figure 15), likely caused by the previous train being delayed, one can hear the noise of the train moving, and grinding of the wheels and tracks. It is noisy and not alarming. There is standing room only for a while before alighting seven stations later at Allenby.
4.2 Allenby station
Riding the train, and as the train arrives at the station there is no voice announcement, unlike at earlier studies at Canary Wharf (Harding, 2024c) and Elizabeth Line (Harding, 2024a). Signs on the station platform are unseen. However, Allenby is a warm red colour, different to other stations, and is the last underground station. And even though one is not a frequent traveller on the Red Line, having a wider knowledge of the design aids one’s correct choice.
Upon alighting (Figure 16), three escalators and four lifts are visible (Figure 6(b)). Choosing the lift, one walks towards the opening entrance. Entering the lift, with two other passengers and a small dog, one can see out towards the platform and escalators. That affords a sense of security, comfort, and convenience (Figure 17). Continuing the journey, the lift doors open, and one walks towards the gateline exit lit by the LED panels above. Follow the light. On the other hand, while the lift route is direct and short, one can look out of the lift and see passengers having a longer journey from the platform to exit when using the escalators.
At the concourse level, a display of prints from the nearby art gallery advertises attractions in the local area (Figure 18). The ‘active’ street appears like an art gallery. An opportunistic way to curate these large spaces and relate the station to its neighbourhood. The original intention was to provide retail space in the underused areas of the concourses. A probable reason for the lack of advertising or retail is land-use restrictions. Nevertheless, one's enjoyment of the experience of moving within the station is unharmed by the lack of advertising or retail.
Moving through the gateline, arriving at the unpaid ‘active’ street where a wall mounted sign indicates three exits, A, B, and C (Figure 19). Owing to unfamiliarity with the location, it is unclear what exit to choose. Fortunately, there is an information board with a map on the wall. Not all stations visited have this affordance. This single entrance/continuing touchpoint affords critical information. There is adequate space to pause and linger before deciding which way to continue one's journey.
Continuing along the ‘active’ street to the chosen exit, one can see the ticketing and information to the right and lifts to the left (Figure 20). Distracted, one has forgotten the exit letter chosen. There is no further map or information to help in English. Not wishing to return to the information board, one turns left to take a chance at one of the exits (Figure 21). Moving towards the exit, the route passes by the paid street to the left. Feeling secure and comfortable, one walks towards the air-conditioning doors, past the doors to the lift. It is a short distance to see the lift. Whereas, owing to a blind turn, one cannot see the escalators at the end of a lengthy passageway.
Continuing the lift journey to the street, without having to wait, one enters the lift, turns and sees the passageway toward the escalators within a safe, secure, and comfortable location (Figure 22). Arriving at street level, neighbouring buildings are close by (Figure 23). Similarly, to Ben Gurion, the station is open to the elements. The shade canopy, a station signpost and a lift shaft are the few visible markers at ground level. As one arrives within the Allenby area in the early evening darkness, continuing to the station location map, there is space to wait and orient oneself to the next destination. Continuing one’s journey across the road, one sees the bicycle path and pavement integration with the streetscape and ‘pop-up’ ventilation gratings necessary for operating the station (Figure 24).
5. Discussion
To address the research question, it is necessary to explicate the surprising similarities and differences experienced at the customer touchpoints along the passenger journey (Figure 2) and triangulate results with literature, for generalisability.
5.1 Better customer experiences benefit everyone
The results reveal actionable insights at each of the critical ‘customer touchpoints’ as follows:
Arriving and Entry: Improved signage outside the station will improve the ‘finding’ experience. For example, the questionnaire survey demonstrated that most participants can find their way at Tube stations (Harding, 2011). To improve confidence, recommendations are that direction signs be located further from the station entrance and point towards the station entry.
Ticketing: The ‘active’ street concept, achieves the anticipated benefits described in Harding (2019) as follows: a) easy movement of passengers at this critical touch point, b) satisfactory space and information for passengers to wait and decide their exit route before onward travel, c) satisfactory space and seating for passengers to meet someone in a safe, secure and comfortable location with a nearby water fountain available in air-conditioned comfort, d) a high LOS and seamless flow of passenger movement, without cross-flows e) a concentrated focus for information and then space for dispersal to up to four different exit/entry points, f) efficient staffing, by having only one gateline. On the other hand, escalator users have a longer journey to the platform than the lift passengers. Some users complain of longer journeys when taking escalators. To resolve this ‘trade-off’ between operation cost and walking distances more passengers could take the lift instead of the escalators. Future technology may afford gateless stations removing barriers. Nevertheless, case 2 mitigates the risk of people bumping into each other. Satisfactory circulation arrangements, provided in case 2, though not in case 1 (Harding, 2019) are vital to avoid slips, trips, and falls (RSSB, 2015), and comply with circulation requirements (Fruin, 1971; 1992; Network Rail, 2015) among other requirements.
Waiting and Circulating: Grouping the vertical circulation concept in case 2 demonstrates that locating the lifts and escalators together towards the centre of the platform achieves the anticipated benefits described in Harding (2019). a) Locating the grouped lifts and escalators at the platform centre affords a visible and accessible circulation space, usable by everyone. b) Four, fully glazed lifts at large and medium stations satisfactorily serve the concourse to platform journey. Overall, this is a giant step forward for inclusivity and service compared to the UK current practice where ‘a minimum of one passenger lift installation should be provided for use by Persons with Restricted Mobility (PRM)’ (Network Rail, 2022: 38). This term is used to define ‘different user classifications including wheelchair users, passengers with an ambulant disability (a physical mobility impairment which doesn’t require the use of a wheelchair), passengers with heavy or large luggage and passengers with young children.' (82). Table 3 compares lift-to-escalator ratios at the Jubilee Line, Elizabeth Line, and Red Line stations. While this is a crude measure, it provides a straightforward way to evaluate the significant advance, from the older UD paradigm, towards the ID discourse in the quarter of a century since the Jubilee Line began operating. c) The use of fully glazed lifts provides a desirable customer experience, contributing towards feelings of confidence, comfort, gentleness, and security. Instead of feeling like a valued customer, the service experience provided in modern stations in London is to treat a person as unwanted, a potential vandal, or criminal inside a steel coffin. Owing to stainless steel-clad lifts, small windows, confusing multiple buttons, and poor signage (Harding, 2024a), the contrasting experience within two contemporaneous lifts implemented in different countries is alarming. d) The video data shows young, fit, and able passengers also like to use the four large and accessible lifts. e) It can be noticeably quicker to use the lift than to take the escalator, owing to the slower and lengthier walking route. The benefits of taking lifts include saving time, physical effort, safety, and space-saving (Harding, 2019). f) The stations are less busy and quieter than the 2030 forecasts anticipated (Harding, 2019). g) Rushing, slipping, tripping, falling, or cross flows incidents were unobserved. That triangulated with the prediction of a safe horizontal and vertical circulation arrangement at the platform and concourse in case 2 (Harding, 2019). Literature reviews indicate almost 50% of serious incidents occur on stairs and escalators (refer to Chart 39 RSSB, 2015). Most at risk of harm from slips, trips, and falls on escalators are elderly people, children, women wearing high heels, and inebriated people (Greenberg and Sherman, 2005). Consequently, case 2 circulation arrangements improved the safety and inclusivity experience. h) It was noticeable that there was sufficient availability of lifts in good locations. Not all four lifts were utilised owing to the strong preference to travel by escalator. This finding triangulates with literature where questionnaire surveys show 95% of the group like to use escalators (Harding, 2011: 38). Perceived lengthy waiting time may deter lift use (Van Hagen et al., 2014). And it takes more energy to stop and restart, suggesting that stopping increases the impact of exercise that could be beneficial to passengers who may wish to burn energy while waiting for a lift (Luciano et al., 2024). i) Using escalators is a strong preference and could be a strongly conditioned behaviour that is not always to the advantage of the user.
While this study provides a good example of the ‘hardware’ to achieve a more inclusive and useable station to improve lift uptake further consideration could be given to condition and ‘nudge’ users to promote lift use, for example: i) turn escalators off during quiet times to familiarise users with lifts and to reduce energy use, ii) show information on how long the lift journey will take, iii) simplify buttons and interactions, iv) make pleasant spaces to wait to reduce the perceived waiting time (Van Hagen et al., 2014), and v) develop stronger guidelines to locate and quantify escalators and lifts for useability and inclusivity.
Boarding and Alighting: Grouping the vertical circulation concept in case 2 demonstrates that locating the lifts and escalators together at the platform achieves the anticipated benefits described (Harding, 2019) as follows: a) there was a good experience arriving at the platform because of sufficient spacing of the escalators that land approximately halfway along the platform. This is an improvement for safety and usability and efficiency compared with earlier examples. The lack of space to wait at crowded platforms required the retrofitting of hazard warning tape, post-occupancy, to warn passengers not to wait at the run-off areas of escalators (Harding, 2024c). b) All ten underground stations have lifts located towards the platform centre. Resulting in lift passengers boarding trains in the centre carriages of the train. They will be able to alight and move to the lifts located in the centre of the platform, board the lift and alight at concourse level. And vice versa. This is an inclusivity service improvement upon earlier examples where a passenger experienced a delayed and difficult journey moving from the centre of the platform to the end of a crowded platform to reach the small lift (Harding, 2024c). c) Locating vertical circulation in the centre of the platform that allows flexibility for passengers to circulate freely at the platform in a good LOS. On the other hand, case 1 demonstrates when escalators descend close to the end wall of the platform, significant pedestrian movement is concentrated at the congested end of the platform, all passengers make a U-turn resulting in a poor LOS increasing crowd safety risks, delaying passengers from boarding or alighting the train (Harding, 2019). Similarly, the study at Canary Wharf (Harding, 2024c) shows the impact of congestion along the platform. Congestion is worse because trains are too crowded to allow passengers to board, and consequently, the platform is crowded, delaying boarding and alighting. Guidance to address the critical relationship of escalator location within the platform is lacking. On the other hand, case 2 provides a satisfactory example that designers could consider. d) The study reveals the importance of locating signs to support the passenger journey from arriving at the station to boarding, alighting, and continuing. Service improvements include providing active native and non-native language boarding times and train destinations information for waiting passengers. Station name signs are visible to passengers when riding on arriving trains. A frequent commuter may not require many signs to either board or alight. Few regular commuters have difficulty seeing signs and finding their way on the Tube (Harding, 2011: 40). Alternatively, the infrequent traveller who may not be familiar with the locality and language requires more help. Recent studies show the difficulty of finding signs for lifts in modern stations (Harding, 2024b). Nevertheless, in his study of older bus passengers, if passengers have ‘a bad experience… they would never use [the service] again and that would increase their isolation in their community’ (Marsden et al., 2008: 6). c) Alighting from the train is surprisingly different to boarding. Alighting requires knowing the station to alight, seeing signs, hearing announcements, and when the train has reached one's destination, and requires attention. Boarding requires selecting the correct platform, knowing the end destination, and knowing which train to board. This is particularly important when trains serve different destinations. Difficulties include unfamiliarity with the city, language, and the names of destinations. Mistakes include boarding the train to the wrong destination. Challenges, particularly at island platform stations, as case 2, are rushing, not seeing signs adequately, and unfamiliarity. Both boarding and alighting from trains result in cognitive difficulties, as someone with ADHD has experienced. Clues and differentiation between the stations help. Where stations are all remarkably similar, like the Red Line, distinct colours assisted decision making. Improvements include better signage. And development of stronger industry guidelines, to quantify and locate escalators and lifts for useability and inclusivity, where case 2 could be an exemplar for busy stations.
Continuing: This study demonstrates that the ‘active’ street concept, with the gateline at the centre, provides a decision, or ‘pause point’ to gather and plan the exit with sufficient space. As was demonstrated on the ABM study (Harding, 2019), the study shows that a first-time, non-native speaker could not navigate confidently out of the station with more than one exit. Upon reaching ground level, the open-air entrances are surprisingly discrete and integrate fire escape stairs. While discrete entrances reduce the visual impact on neighbours, they are harder to see when hidden behind fresh air ducts and other services. Being able to see the buildings and streets helps with reorientation and arrival. Ventilation exhausts integrate within the streetscape (Figure 24). Station entrances can provide a stronger sense of arrival into a new neighbourhood, for example, Canary Wharf Jubilee Line Station (Harding, 2024c). Entrances can also integrate with fire exits, vent shafts, and oversite developments (Harding, 2024a). Further improvements include better signage, and how fewer entrances could ease wayfinding and integrate with streetscapes (refer to Table 4).
5.1.1 Influence of comfort on inclusivity and usability
Case 2 provides unobstructed seating at the platform and the concourse paid and unpaid routes, improves comfort that benefits inclusivity and useability owing to older passengers ‘desire for a gentler, more comfortable environment’ (Marsden et al., 2008: 5). A lack of seating may have resulted in a third of participants not using a seat when tired, and half felt exhausted after travelling on the Tube (Harding, 2011). While newer standards require seats at lift landings (Network Rail, 2022), seats are rare outside platform areas (Harding, 2024c; Harding, 2024b). Consequently, case 2 improved the seating experience throughout the station and is an innovative example of the benefits of integrating SD in the early design stage.
5.1.2 Influence of ‘active street’ on security, inclusivity, and usability
Case 2 demonstrates that integrating the ‘active street’ and the ‘grouping of vertical circulation' improves security, inclusivity, and useability by integrating passenger movement, with long connecting sightlines. Hillier’s (2004: 38) analysis of crimes in urban areas concludes that burglary is entirely located in streets with low visibility and low connectivity. Such as side alleys or in buildings hidden from view, by hedges. He concludes that a safer street network has continuous rows of buildings, on either side, with no gaps, linear and with long sightlines, without a second access such as an alley (Hillier, 2004: 39). In comparison, older Tube stations typically have short sightlines and convoluted, narrow access tunnel arrangements. That could explain why some participants experience crime on the Tube, while half of the group experience anti-social behaviour (Harding, 2011: 39). Transferring the security benefits by applying urban theory (Hillier, 2004) to underground passageways and integrating that synthesis is a significant contribution to station design theory, and an example of the benefits of integrating SD in the early design stage.
While industry standards recommend lighting levels and light reflectance values for materials (BSI, 2018), architects usually provide colour selections and materials. Surveys show that half of the participants experience dark and poorly lit Tube stations (Harding, 2011: 39). Glare was evident in the lighting design at Canary Wharf station (Harding, 2024c). Lighting was satisfactory at Farringdon Station (Harding, 2024a). Similarly, this study shows lighting was satisfactory, including the LED panels above the gateline. The warm and neutral colours of the walls and ceilings enhance the feeling of security and inclusivity, similar to a shopping centre or a gallery. Such a strong interior colour and lighting selection is beneficial, according to Van Hagen et al. (2014), who describe ‘lust’ passengers who travel for pleasure and benefit from an exciting environment that leads to a better waiting time experience. Alternatively, commuter ‘must’ passengers respond better to a calmer environment. The moment ‘must’ and ‘lust’ passengers feel reassured, reversal to a more playful or relaxing state of mind is possible in which consumers enjoy or appreciate an entertaining or relaxing waiting environment (Van Hagen et al., 2014). Implemented with both bright and warm colours, and neutral grey at both concourse (Figure 10) and platform (Figure 13) produce satisfactory results for both ‘must’ and ‘lust’ passengers. Such increased experience of security, inclusivity, brightness, and usability at Red Line stations is desirable. This may attract more users and increase ridership, drawing from, hopefully, a reduced car-using population. It is an innovative example of the benefits of integrating SD insights from observations and syntheses in the early design stage.
5.2 Influence of gentleness on inclusivity and usability
Case 2 demonstrates gentle and straightforward access for lift and escalator users, requiring only two level changes to transfer the 23-m depth from the street to the platform level. Passengers appear calm and unrushed, and frequent users know where they are going. This achievement for inclusivity was owing to the ‘group vertical circulation’ and ‘active street’ concepts' (Harding, 2019). They were new ideas to address findings that half of participants moving in older convoluted Tube stations were lost or disorientated (Harding, 2011: 39), more than half feared losing other members of a travelling group (Harding, 2011: 40), and half experienced excessive changes in level (Harding, 2011: 39). Similarly some aspects of new mined underground stations were found to be disorientating (Harding, 2024a). ‘Implementing these concepts effectively minimises the alienating and disorienting aspects of new buildings and forms of transport' (Yardley, 2013: 128). And after changing the level gently re-orientates and restores the cognitive, or mental map (Mastrodonato et al., 2016: 8). Overall the implementation of case 2 is an achievement in a new metro in a city with no history of underground metros, by reducing the experience of VS (Harding, 2013: 13), and sufficient space for re-orientation at all levels of the station. These are innovative examples of the benefits of integrating SD insights from observations and syntheses, developing new ideas to address VS, refining, and implementing these modifications during the early design stage.
Riding the noisy train was unpleasant, and the majority of journey time is spent on the train. Addressing the riding experience is vital. Similarly, three-quarters of participants experienced noisy stations and unclear voice announcements at stations (Harding, 2011: 37). Train noise is excessive on Jubilee Line trains and in lifts (Harding, 2024c). Whereas Elizabeth Line trains sound quieter and announcements are clear (Harding, 2024a). This suggests that integrating SD process in the early design is necessary to address the acoustic experience within the train. Further research must consider the experience of gentleness when riding the train. For example, by increasing sound insulation in the train car, reducing the noise of the train and track interface, and enabling clearer voice announcements.
5.3 Replication and repeatability of station design
Case 2 demonstrates the passenger experience benefits of having familiar and repeatable designs across the ten station sites (Figure 6) and developing more inclusive, usable, efficient, and desirable public transport. The repeatability of the station design is a contribution to developing UN’s SDG11.2 – affordable and sustainable transport systems. In contrast, recent Elizabeth Line stations were all unique, and costs increased from £14.8 to £17.6 billion. Stations costs increased between one-and-a-half and fivefold. And the opening was delayed from December 2018 to May 2022 (NAO, 2019). Flyvbjerg et al. (2021) demonstrate that unique designs result in cost and budget overruns. Repeatable solutions reduce costs and programme delays because lessons learnt quickly reduces risks of delay. Case 2 repeatable designs, refined in the ABM study (Harding, 2019), delivered a new conceptual model for inclusivity and efficiency successfully implemented in ten stations in the real world. They are an example of how ‘[b]etter service design provides the key to market success, and more important, to growth’ (Shostack, 1984). Extending the practical and theoretical use of SD from financial services to developing inclusive and desirable experiences and deliverability within the built environment sector.
5.4 Designing for everyone
Case 2 innovatively transfers SD processes to the BE sector and consequently improves the travelling experience for everyone. This study shows that integrating SD methods into the built environment design and construction processes is practical and beneficial to inclusion and benefits wider social equity, economic growth, and environmental protection aims. SD is a valid ‘next, next’ design method for designers to consider at the early design stage within the built environment. This study frames design as a form of discourse, similar to the scientific discourse that requires constant evaluation, revaluation, search, and research. In this case the discourse focused upon what features provided an inclusive service in underground stations. This study contributes towards developing UN’s SDG 9 – industry, innovation, and infrastructure and SDG 9.1 – developing sustainable, resilient, and inclusive infrastructure goals.
6. Conclusions: improving the path less travelled
This post-occupancy study concludes a longitudinal study (Harding, 2020b) that demonstrated how the SD stages (Bhavnani and Sosa, 2008), observation, synthesis, new idea, and refine stages were implemented in the early design stage. Case 2 was developed as a model for inclusivity and service and refined in an ABM study (Harding, 2019). However, it was not known whether case 2 would deliver those anticipated benefits in practice. To address this question, a post-occupancy study of passenger interactions with the circulation systems in underground stations developed, repeating the auto-ethnographic methodology (Harding et al., 2016; Harding, 2024c, 2024a) transferred from ethnography (Buzard, 1997). That integrated the socio-material interactional and empathetic co-experience research methods used in the product and service field (Shostack, 1984; Battarbee, 2004).
Case 2 provided an inclusive service owing to the ‘active street’ concept concentrated entry and continuing passenger movement, ticketing and information and decision points, and afforded space for seats and drinking fountains. Seating at concourses and ticket halls, and clear wayfinding information, and desirable finishes and clearer information provided to benefit the user experience. The ‘concentrate vertical circulation’ strategy increased lift quantities, grouped lifts close to escalators in visible locations, and reduced the VS impacts of the deep stations. That resulted in a good LOS within the platform and concourse spaces. Because a good LOS improves inclusivity (Harding, 2019) and access for everyone (Martens, 2018: 122).
Results triangulated with earlier user questionnaire studies (Harding, 2011), observations (Harding, 2024c), synthesis of the literature (Harding, 2020a), and new ideas and refinements in design studies (Harding, 2019). While UD paradigms were implemented at Jubilee Line underground stations and satisfied statutory regulations, they did not achieve current inclusivity and usability aims within a busy station context (Harding, 2024c). Consequently, this study updates earlier UD paradigms that aim to afford access to a wide range of users (Martens, 2018: 122) to ID discourses that aim to afford access to everyone (Martens, 2018: 122). This study shows, for the first time, that SD is a valid ‘next, next-generation design method’ (Cross, 1982). Transferring SD to the built environment sector resulted in case 2. That was shown to deliver inclusive co-experiences and contribute to the aspiration to ‘… live and work in an inclusive world’ (Clarkson and Coleman, 2015).
6.1 Better customer experiences benefit everyone
Taking the path less travelled through the experience of a lift user and conducting a post-occupancy study through the SD and inclusivity lens provided valuable actionable insights. Including: a) both lift and escalator users enjoyed a satisfactory LOS and inclusivity. In contrast, a typical UD approach, shown in case 1 (Harding, 2019) and a Jubilee Line station (Harding, 2024c) limited the type and quantity of passengers who can access stations. b) This case study shows how case 2 provided an inclusive service in two busy underground stations serving the central business district area. And revised canonical theory where previously multiple lifts were suitable only at end-of-line and airport stations (Fruin, 1971). c) Integrating SD processes into the early design was possible and provided inclusivity and usability benefits for everyone. d) This study showed that integrating inclusivity as a critical part of the service experience resulted in an integrated lift passenger journey. e) Further improvements are necessary to signage with the passenger journey. As a consequence, this study builds upon the research of other recent studies of modern urban underground stations in a cut-and-cover (Harding, 2024c) and mined context (Harding, 2024a), and transferring this method to a different country. And expands SD’s definition to include inclusivity. Overall, this post-occupancy paper was an essential review that demonstrated the benefits of transferring the SD methodology (Shostack, 1984; Design Council, 2010; Bhavnani and Sosa, 2008) to the design of the built environment.
Service Design is all about making the service you deliver useful, usable, efficient, effective, [inclusive], and desirable. [Amended Design Council]
6.2 Innovations – better customer experiences benefit everyone
Actionable insights and innovations are i) the strong correlation between the anticipated inclusivity and service benefits modelled and described in Case 2 (Harding, 2019) and the observed experience in this post-occupancy study of two implemented case 2 stations, albeit the observed passenger numbers are lower compared to 2030 modelling (Harding, 2019). ii) LOS appears to be a valid and objective proxy to probe inclusivity using canonical pedestrian movement theory (Fruin, 1971), iii) the observed Vertical Severance (Harding, 2013) experience was reduced by the adoption of Case 2 group vertical circulation concept, iii) integrating ‘next, next’ generation SD methods and inclusive design aims produced a satisfactory LOS that was beneficial for all passengers, iv) Case 2 that integrated ‘next, next’, SD methods (Bhavnani and Sosa, 2008), socio-material underpinning theory (Slack, 1999), and reduced Vertical Severance (Harding, 2013) produced a satisfactory solution for inclusivity in praxis, that will benefit SDG 9 Industry, innovation and infrastructure. v) New ID and next, next generation conceptual models indicated by Case 2 are supported in both theory (Harding, 2019) and praxis, vii) Case 2 represents a new conceptual model for new inclusive underground stations and provides a starting point for a new canon of ID guidelines applicable to the built environment, viii) Case 2 was repeatable at ten stations (with variations) that improved deliverability and affordability of new metros that address UN’s SDG 11.2 – affordable and sustainable transport systems. ix) To reflect new ID discourses to provide access for everyone (Martens, 2018), canonical pedestrian movement theory (TRB, 2010; Fruin, 1971) and disability discourses (Goldsmith, 1976) require revising in light of these conclusions. Finally, readers, who may be designers, researchers, and policymakers are hopefully inspired by Case 2 and this co-experience method of inquiry to develop designs and research that serve everyone, so that we can all ‘… live and work in an inclusive world’ (Clarkson and Coleman, 2015).
6.2.1 Limitations
Everyone has a unique experience. And in this study the participant observer is a 61-year-old male, with minor disabilities, an architect, husband, father, brother, uncle, carer, and a frequent commuter on the train network. While literature triangulated the study’s findings, subjectivity, and the ‘lived experiences’ of the participant observer limits generalisability. It is necessary to include participants with different lived experiences when conducting further research of this type.
6.2.2 Future research
Table 4 summarises recommendations to improve inclusivity service in practice. Designing for everyone requires further exploration of theoretical and practical implications of a) the differences and similarities between different user types and groups; b) vertical circulation and preferences/experiences of lifts vs escalators; c) the waiting and travelling experience for everyone, particularly when using lifts; d) the critical need to incorporate the perspectives and experiences of a more diverse range of users to achieve a comprehensive understanding of inclusivity; e) to inform the design of new metros, a similar questionnaire survey (Harding, 2025) could be implemented to elicit actionable insights from a wider group of Red Line users; and f) a new study could repeat this methodology when the Red Line is busier following the operation of new LRTs and future metros.
Acknowledgements
The author thanks the editor and three anonymous referees for their comments that improved the readability and clarity of the finished article.
The first modern underground stations with lifts from street to train commenced service in London in 1999 (Jubilee Line Extension) and in 2022 (the Elizabeth Line).

























