Linea
Client
Linea Mobility
Year
2025
Role
Product design, UX research, design system
Discipline
Digital Product
A transit app for Lisbon’s trams and buses, designed from the street up: forty rides of research, one honest arrival time and a system that scales.
01 — Context
Linea Mobility is a small Lisbon start-up with an unusual asset: live positions for every tram and bus in the city, cleaned up and accurate to the second. What it didn’t have was a product. Riders were still juggling a paper map, a timetable PDF and a fair amount of guesswork.
I joined as lead product designer for nine months, working alongside two engineers and a data scientist, from the first interviews to the release of the design system.
02 — Challenge
Lisbon is hard on transit apps. Hills break GPS, trams share narrow streets with delivery vans, and on some lines a third of riders are visitors who don’t speak Portuguese. The apps people relied on showed scheduled times that were often ten minutes off.
The brief was simple to say and hard to do: tell people when their ride is actually coming, and make it readable in four seconds, one-handed, on a crowded tram.
03 — Process
We started on the street. Over three weeks we rode forty routes, interviewed 32 riders at stops and ran a diary study with twelve daily commuters. The wall in the studio filled up fast with quotes, photos of stop signs and notes about missed connections.
From there we built four personas, from a night-shift nurse crossing town at 6 a.m. to a visitor hunting for the right stop in Belém, and mapped each journey moment by moment. One pattern stood out. Anxiety peaked in the two minutes before a ride arrived, not while planning. So we designed for the stop, not the map.
04 — Solution
Linea opens on the stop you’re standing at. Each line shows a single number, minutes until arrival, drawn from live data and clearly marked when it’s only an estimate. Saved trips sit one thumb away, and the whole app works in Portuguese, English and Spanish.
Underneath is a design system of 64 components built on one warm yellow, an ink black and an off-white tuned for direct sunlight. The same tokens drive the app, the web planner and the signage at pilot stops, so a line badge looks the same on a screen and on a steel totem.
05 — Outcome
Six months after launch, Linea had 180,000 monthly riders. Support tickets about wrong times fell by 38%, and the city asked to extend the signage pilot to twelve more stops.
In use
In numbers
180k
Monthly riders after six months
−38%
Tickets about wrong arrival times
64
Components in the design system
Credits
Product design & research
Mara Ellis
Engineering
Tiago Mendes
Data science
Inês Calado
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