HUMAN FACTOR

Human factor is having multiple facets that is also sometimes defined as Human Ergonomics. The website Humanfactors101 notes that we design activities, plant, processes and procedures in such a way that takes into account human imperfections, this is human factor.

In Transit systems, there are many human factors design at play, particularly in the operation sections. In the design of stations, we also need to consider human ergonomics or human factors as part of our design. Many of these are already actively at play and these have been included via many statutory codes (Life Safety, say egress stairway, where such steps for enclosed stairs used for escape could be of a much narrower tread and higher rise, whilst public staircase used for operational Vertical Transport (VT) will be much wider riser and shorter riser, defined by design standards), or standards for disabled requirements via local, American Disability Association (ADA) standards, etc. All these are engineered to ensure that human beings are able to use these spaces with all potential thoughts and requirements required by various sub-sections of our populations.

The section related to edge effect discusses the 300mm additional width requirements, in UK and others, whilst not in Hong Kong is also a definition of Human Ergonomic requirements, which one could say is considered in the former systems, however ruled out in the latter systems. Which could have been not required due to the dense condition of Hong Kong streets, hence people are used to walking close to the walls of subway, etc. Similarly, the design standards used for escalators in the Hong Kong MTR are far more onerous than metro system around the world, such as Singapore MRT, UK LuL, etc. Which is required as the number of passengers using the station in HK, the short (2.X minutes train headway), etc. All requires the standards to be uplifted to increase safety and security, compared to the other standards.

Similarly, there are many aspects of transit-built form that needs to be reviewed to address such requirements, say the top of the counter for ticket boots, needs to be easily accessible by wheel charger user, or placements of elements like garbage bins, signage pole, etc all needs to be located with the passenger movement in mind.

Whilst a Human Factor professional may be nominated to review and address the station design needs for the general public requirements, many of these requirements could easily be incorporated by sympathetic station planners and designers

Designers needs to allow for all aspects of people who use the transit buildings, passengers, operators, maintenance (Daily, periodic or even once in many years), life safety personnels, etc. That all modes of operation of the building, elements of building, etc, needs to be reviewed for design needs. Many of these are human factor requirements, which can be considered to be common sense requirements. Let's illustrates some for reference:

1. Barrier:

International standards now accept that barrier to deter people from falling from height, needs to be 1100mm tall. All international and most local codes not only define this height, but also the imposed load that the barrier needs to take.

• The 1100mm height: An average human being will have their body pivot point below the 1100mm off the floor. Implying that if you do lean against the barrier, your body will not pivot on the barrier and fall to below.

• This barrier will then have to take the imposed loading that building types may need to be designed for. BS 6399-1 recommends imposed loading on barriers to be 3kN/m (For Areas susceptible to overcrowding). However, many stations are designed to 5kN/m crowd load (HK MTR, etc), which is also what most stadiums are designed to.

• These loading are also called crowd, loading, such loading also needs to be designed to wall claddings, to ensure that walls cladding does not fail in emergency conditions, when there are crush load of passengers evacuating. If the wall cladding fails, then the ensuing damage may cause stampede, creating public safety issues.

2. Line of Sight:

• Unobstructed Views: Transit public areas should have splayed, chamfered, and rounded line of sights. This ensures unobstructed visual and physical access.

• Natural Movement Transition Space: Designing for smooth movement transitions enhances user experience. etc.

Whilst I have stated this to be common sense, many of them are part of the design criteria from the operator, many part of the building codes, many of them are then formulated by Human Factor Consultants, who have a much more heightened sense of such requirements and will work with the design team to implement this in the system.