Case study
Passenger information displays
A passenger display gets a few seconds to tell people where they are, where the bus is going and how long until their stop. The screens hang inside moving buses and get read from a distance, often by someone worried about missing their stop.
What it does
The onboard computer already knows the route, the stop sequence and where the bus is. The passenger display turns that into something you can read from your seat. It shows a route line, a moving bus marker, the next stop, the final destination and accessibility icons.
Nobody touches these screens or stops to explore them. They have to work out of the corner of your eye, in sunlight, at an angle, in the two seconds a passenger gives them.
These screens are in daily use all over France, in buses, at train stations and on airport shuttles, across different vehicles and operators.
Why it's hard
The screen has to stay readable in bright sun and from a distance. It also has to handle the awkward cases. The first stop, the last stop, a diverted route, a stop with accessibility info, and the moment the next stop changes.
It's tempting to cram everything onto one screen. I split it instead. The route view tells you where the bus is going. The next-stop view tells you where you are now.
A screen is only readable when the data, the layout and the viewing distance all line up.
How I built it
I built the whole chain behind these screens: waking them up over an RS232 serial link, rendering what they show, and keeping it in sync with the server live. The route view is one horizontal timeline. Stops are in order, the bus is clearly placed on the line, and the next stop stands out.
A separate stop view gives the current stop name, line number and accessibility info the room they need. Both screens share the same look, but each one does one job.
In short
- Route progress with a clear bus marker and the stop sequence.
- A next-stop view with big type and an accessibility icon.
- High-contrast layouts for the TFT screens inside the bus.
- Wired to the live journey data from the onboard computer.
- One visual style that works on wide route maps and portrait stop views.
Choices I made
Readable from metres away
Big type, few colors, strong contrast. People read these screens from several metres away, usually while the bus is moving.
One idea per screen
The route map and the next-stop view are separate, so you can read either one without the other.
The wheelchair icon belongs to the stop
The wheelchair icon is part of the stop data. It shows up on the stops it applies to and stays attached to them.
Built for a moving bus
Stable layouts, no fine detail you'd have to stand still to see, and nothing that expects a passenger to be standing in front of the screen.
The screens
The result
Whether passengers look at the route map or the next-stop screen, they get the same answers. The look stays put while the journey data underneath keeps changing.
Most of the job was working out what a passenger actually needs out of everything the onboard computer knows.