4.1 Device Agnostic
4.1.1 QR Codes should be “device agnostic” and be natively supported across devices (Android, iOS etc). Where other non-standard QR Codes, which require bespoke apps are used, these should be in addition to the standard natively supported QR Code and provide the same URL endpoint.
4.2 Resolution
4.2.1 QR Codes need to be printed using a quality printer to ensure a crisp edge to the image contents. This enables easier scanner reading and a greater distance away before it becomes unreadable.
4.2.2 With this in mind, the recommendation is to use a printer with 300 dpi or better resolution. This should not be an inkjet type printer – unless it is using special waterproof inks to avoid bleeding in damp conditions.
4.2.3 For digital screens, a resolution of at least 150x150 pixels: depending on the scanning environment is required.
4.3 QR Code Size
4.3.1 The code itself should be a minimum of 30 mm × 30 mm; the ideal size to allow easy scanning at distance is 50 mm x 50 mm.
4.3.2 QR codes require a quiet zone (blank margin) and adequate module size, the quiet zone should be at least 4 times the size of a single module (the smallest square within the code).
4.3.3 The code should have a minimum 10 mm margin. However, the required 4 module blank margin for a large QR Code may result in a larger margin from panel edges being required, and be at least 15 mm from any text or symbols.
4.3.4 The recommended sizing of the QR code accounts for:
- a bus-stop timetable being typically scanned at ~30–50 cm; a reliable baseline is the “10:1” distance-to-size rule (size ≈ distance/10);
- older phone cameras;
- low-light conditions; or
- slight panel curvature or wear.
4.4 Labelling
4.4.1 QR Codes should have a label in close proximity with text describing the purpose of the content that the QR Code takes the user to. For example: “Scan for live departures (this stop)” with a short typable URL directly beneath/alongside.
4.4.2 It may be helpful to include safety messaging alongside the label similar to:
4.4.3 “This QR code links to official bus information. Always check the web address before proceeding.”
4.4.4 The label typography should be 12pt minimum, 14pt preferred, in a sans-serif font and avoid italics and whole words in block capitals.