Self-service terminals and kiosks

The term "self-service terminals" covers all kinds of devices in public spaces a visitor might interact with. For convenience sake, we will also use the shorter term "kiosk" in this article, even though it does not convey the exact same meaning as "self-service terminal".

The accessibility requirements for self-service terminals go beyond what is expected of accessible websites and apps. Unlike self-service terminals, websites and apps are used on familiar devices such as a computer, tablet, or smartphone, which can be customised to the user's personal needs thanks to accessibility settings or assistive technologies. A self-service terminal on the other hand is a closed environment: the device cannot be customised and must therefore offer various interaction methods. Moreover, the user has no prior knowledge of how they work.

We begin with a few examples of self-service terminals, and then provide recommendations for designers and developers of accessible self-service terminals, including: environmental factors, the accessibility of the device itself, and providing a customisable user interface. We conclude this article with practical applications, referring to the European standard.

Even when all of the advice contained within this article has been taken into account, providing alternatives to your users remains important. Make sure users can contact an employee who can help or take over the kiosk's commands at all times.

Examples of self-service terminals

There are many devices in public spaces that we use to perform a variety of tasks:

• Look up information using a kiosk in a museum or tourism centre
• Consult passages or look up routes on the information kiosk in a train station or bus stop
• Withdraw money from an ATM
• Pay in a store using a payment terminal
• Register for the queue in a post office or town hall
• Sign up for a hospital appointment
• Use the self check-in in a hotel or at the airport
• Cast your vote on election day through a voting machine
• Buy a drink or coffee from a vending machine
• Buy a ticket from a parking meter or from a ticket vending machine at the train station
• Use the self-scanning checkout and fruit scales in the supermarket
• Pick up a parcel from an automatic parcel machine
• Place an order in a takeaway restaurant
• Return books at the library
• Etc.

These activities can only be accessible experiences if the devices are physically accessible and provide multiple operating methods.

Environmental factors

• Is a blind or visually impaired person informed of the fact that a self-service terminal is present? Does the device sufficiently stand out from its environment? Is there a tactile guideline present to lead the user to the device?
• Can everyone physically reach the device? Make sure the route between the entrance and the device is free of obstacles, and sufficiently wide as well. Provide sufficient space around the device to maneuver a wheelchair.
• Pay attention to the lighting conditions: if the device is outside, shield it from sunlight. If it is inside, provide appropriate lighting: sufficiently strong, well directed, and not blinding.
• Provide the option to sit down while waiting your turn and while using the device.

The device

A self-service terminal is an unfamiliar device to the user: they have no prior knowledge of what the device looks like, what functions it offers, and how it works.

• The physical layout of the device must be very simple and predictable. It should also be immediately clear what the device is for.
• Pay attention to the height of the device and its controls when designing its physical form, as well as whether a wheelchair can fit underneath. Is the device usable by large, small, and seated users?
• If physical actions are required (inserting a card, taking out a ticket,...), the user must be able to do this one-handed while requiring minimal grip, strength, and wrist rotation.
• A self-service terminal is only accessible when the device itself offers multiple different operating methods: if it has a screen, the information shown on the screen must be read to blind people. Take this into account in the physical design of the device by including a speaker and/or a jack for headphones. If no audio options are present, a voice interface cannot be added either. Consider its physical location as well: position the speaker for optimal comprehensibility and discretion. Place the headphone jack in a logical location that is easy to identify.
• If the terminal has a motion detection function, then keep in mind the unpredictable movement patterns of users with e.g. developmental coordination disorder.
• Provide disinfectant gel.

User interface

Most users are unfamiliar with the device and its operation.

• Keep the user interface simple and uncluttered. Provide no more buttons than necessary, make them large, and label them clearly.
• Always make it clear how to go back or undo an action.
• Keep the multisensory principle in mind. Can someone who cannot see or hear operate the device? The device must provide these accommodations itself, as it cannot use the usual assistive technologies that a blind or deaf user is used to on their own device.
• If the device has physical buttons: are they clearly labeled in Braille and with high-contrast letters?
• If the device has a screen: choose an easy to read, high-contrast font, and consider offering a function to enlarge text. Blind users also require an alternative for the screen. Speech output is the most obvious solution.
• If the device has a touch screen:
  • Make sure the click areas are sufficiently big and do not place them too close together.
  • Calibrate the device properly so that users do not have to exert unreasonable amounts of pressure, or can accidentally activate something at the slightest touch.
  • Provide an alternative for blind users, such as physical buttons or controls as found in screen readers for smartphones and tablets with a touchscreen.
• If the device produces sound: provide the ability to adjust the volume.
• Most Web Content Accessibility Guidelines also apply here:
  • Provide ample time for all actions
  • Avoid moving and flashing elements
  • Caption videos
  • Etc.

Case studies

• Touch-screen voting machines and ATMs come with an audio variant: if the user plugs in headphones, the screen shuts off for privacy reasons, and spoken instructions take over. Operation happens through physical buttons that are also still present on the device.
• Some devices can be controlled through an app: the user can perform all actions on their familiar, accessible device. The app then instructs the device to print a ticket or open the right door of the parcel delivery machine, for example.
• Some banks allow you to withdraw cash from an ATM through the app. App and ATM exchange data via a QR code and the money comes out of the slot. If the bank's app is easily accessible, this allows you to indirectly work independently with an inaccessible device.
• The JAWS screen reader is best compatible with a Windows environment. A variant exists that allows for accessible information kiosks: video example.

European standard

Because a self-service terminal is a closed environment, the Web Content Accessibility Guidelines are not sufficient. We therefore refer to the European standard EN 301549. Version 3.2.1 can be downloaded for free from ETSI's website. Be sure to read these chapters:

• Clause 5.1 Closed functionality: as you cannot connect your own assistive technology to a self-service terminal, this clause describes what functionalities the device must provide.
• Clause 8.3 Stationary ICT: this claus provides information on hardware accessibility such as heights and underrideability.
• Clause 8.4 Mechanically operable parts: this clause contains information on what a keyboard should look like, and how much strength may be needed to remove something from a machine.
• Clause 11 Software: has a section on what is expected for "closed functionality" for almost every WCAG criterion.