House-of-Quality Approach for the Design of a Minibus to Transport Visually Impaired and Wheelchair-bound Passengers

In the modern era, machinery designed to assist people should satisfy the requirements of all users, including people with disabilities. This study aims to design an ergonomic vehicle that is comfortable and safe for people with mobility needs (wheelchair-bound passengers) or visual impairment. First, we conducted a literature survey on the definitions of terms such as disability, ergonomic design, house of quality (HOQ), and safe transportation. Next, we gathered anthropometric data of people with mobility needs or visual impairment, and their requirements for safe and comfortable transportation. We used HOQ to capture the voice of consumers and design a suitable technical response to their needs, and utilized computer-aided design (CAD) to convert all the designs into 3-D prototype vehicle models. Based on the needs of people with disabilities and on the results of anthropometric calculations, the vehicle should include a lift wheelchair (15.7%), four folding passenger seats (15%), a handrail dimension (11.4%), and a handle pole (10.4%) for people with visual impairment. This ergonomic vehicle design will result in increased overall user satisfaction.

Computer-Aided Design (CAD); Ergonomic transportation; House of quality (HOQ); Mobility of people with disabilities; Wheelchair, infrastructure for people with disabilities

    Ergonomic vehicular design for the disabled can increase accessibility and transportation safety. In addition, it is an indicator of a nation’s culture and its respect for human rights. Human health and safety have become a priority for industrial management in the last decade, and this trend is reflected in transportation in Indonesia (Lawalata and Agah, 2011; Sukapto et al., 2019). Moreover, Berawi et al. (2018) noted that infrastructure and regional development, which is closely related to human health and safety, will have a positive impact in terms of economic growth. Infrastructure and regional development correlate closely to each other in helping the economic growth of a nation. In this digital era, people need transportation for improved mobility. Here, “people” includes those with disabilities as well. There are four types of disability: physical disabilities, intellectual disabilities, mental disabilities, and sensory disabilities (blind disabilities, deaf disabilities, and speech disabilities). Also, the number of people with disabilities is not insignificant. According to data from the Ministry of Social Affairs, as of 2010, the total number of people with disabilities in Indonesia was approximately 11,580,117 (Halimatussadiah et al., 2017). However, in this country, adequate transportation for people with disabilities is generally insufficient and aspects of the users’ safety and comfort are not considered. It is widely accepted that people with disabilities have fewer opportunities and modes of transportation at their disposal, compared to those who are not disabled. This results in the former group of people experiencing a lower quality of safety and comfort in transportation facilities (Parragh, 2011). For people with impaired mobility, either sensory or cognitive, mobility relies on having access to transportation services when they want to travel anywhere and anytime, obtaining information about the services, having the knowledge of how to use them, having the ability to use them, and having the means to pay for them (Suen and Mitchell, 2000).

People with disabilities refers to those who have physical and/or mental disabilities that interfere with and hinder their daily activities. Such people have the right to receive equal treatment from the state and not feel excluded from general society in their own country. This can be achieved by fulfilling their right to access to public facilities, as stated in the ratification of the International Disability Rights Convention, whose mission is to protect, respect, promote, and fulfill the rights of people with disabilities (Bodaghi and Zainab, 2013). There are official technical guidelines for facilities, and accessibility in buildings (Gray et al., 2003; Contents, 2009), with the ultimate aim of: (i) providing equal standing, rights, and meeting obligations to the disabled; and (ii) increasing the societal role of people with disabilities and the elderly. Integrated, inclusive, and sustainable facilities and considerable effort are needed to ultimately help people with disabilities achieve independence and welfare.

Design of specialized vehicles for people with disabilities has been carried out by several institutions or researchers to increase accessibility for the disabled. Dejoux and Armoogum (2010) carried out a survey to analyze the difficulties faced by people with disabilities during travel. Their research mentioned that 8.2% of the disabled passengers faced difficulties when using a car. This study focused on physical disabilities (especially wheelchair users) and sensory disabilities for blind people and those with visual impairment. They considered an easy-to-use car design that would be accessible for various kinds of passengers. According to existing research into car design that includes easy access for wheelchairs, there are several important factors to be considered, for example, the height of the seats, doorway dimensions, distance between the seats, and suitable handholds. Petzäll (1993; 1995) conducted an experimental study to find the appropriate dimensions of a vehicle that was to be used as a taxi for the disabled. Chen and Wong (2014) produced a prototype design of a movable ergonomic seat for elderly and handicapped passengers. The seat had three primary functions, lifting, rotation, and shifting, for assisting the passenger with sitting down or leaving the vehicle. Haslegrave (1991) suggested that access into or out of the vehicle was a major issue for both disabled drivers and passengers. In contrast, there is little research on accessibility for blind people. Generally, individuals with blind disabilities are assisted by guiding blocks, sticks, handles, and layout in braille. Virgili et al. (2018) reported that lamination and high levels of color contrast can aid those with low vision to see objects more clearly.

    There are numerous manufacturers trying to incorporate the concept of human comfort for the disabled into vehicle design. For example, Allied Mobility specializes in the design and manufacture of vehicles for the disabled, all of which are fully wheelchair accessible. Toyota, Honda, Mazda, General Motor, Nissan, etc. have made efforts to build vehicles that are fully accessible to wheelchairs and mobility scooters. In order to make a vehicle fully disability friendly, there are many areas that need to be modified, including the layout and other accessories. Most companies use minibuses as the basis for disability-friendly car designs due to the consideration of the limited capacity of people with disabilities that need to be served, such as with services in schools and universities. The research and development in automotive design for disabled passengers is an ongoing process. The primary goals of this research are the optimization of the number of wheelchairs that can be put into a vehicle and the increase of the comfort level of people with mobility needs and/or visual impairment. Vehicle design should be undertaken with a desire to provide safety, and easy and ergonomic access to accommodate both the wheelchair and the disabled person. Anthropometry–ergonomic approach coupled with quality function deployment (QFD) for the design of doors, seats, handles, and layout has emerged as a strong basis on which to provide innovative and comfortable vehicular designs for people with mobility needs and/or visual impairment. QFD is beneficial when creating new products and services, it can also be used to review and improve existing ones (Hartono et al., 2017). QFD has two main features: translating customer or user needs so that the product has the desired quality characteristics (design stage) and describing the identified quality characteristics so that control points in production are maintained (production stage). 

Based on the explanation of the research goals and research results concerning the design of a safe and ergonomic vehicle for disabled people, the conclusions are: (1) There are several needs and wants of people with mobility and visual impairment. Requirements with the highest priority and with large percentage scores in our results are a wheelchair lift (15.7%), the wheelchair lift dimensions (15.0%), handrail dimensions (11.4%), and a handle pole for the blind (10.4%); and (2) The anthropometric data we collated regarding people with mobility needs and people with visual impairment were successfully used to design vehicles for people with disabilities, and to meet the users’ need for a more accessible, ergonomic, spacious (for peoples with mobility need), simple (for people with visual impairment) and safe vehicle. The required large interior space can be created using ergonomic folding seats, so it can accommodate two wheelchairs and allows blind people to move and sit freely on the folding seats.

The ergonomic handrail and handle pole can increase the safety level of a vehicle while it is in operation. In the future, the interior (such as the design of the vehicle pedestal, buttons and so on) needs to be developed further so that we can improve passengers’ accessibility and sense of security.