The Meridian Brief
A new client arrives
"We received a proposal request this morning. The Meridian Transit Authority — full system redesign. Kiosks, mobile ticketing, station wayfinding, brand identity. Nineteen stations, two million daily riders."
Two million riders. Sable's pen stopped mid-stroke on a practice layout. She'd been at Indent for three days. The biggest thing she'd ever designed was a campus event poster.
"Finally. Their current system is a graveyard of bad decisions — every station is a different decade's mistake layered on top of the last. Someone finally admitted it's broken."
"I rode the Green Line over the weekend to see the stations. I noticed the transfer signs at Central pointed me left, but the actual platform entrance was back the way I came. I walked the wrong direction for two minutes before I realized."
"When you approached that sign, what picture of the station did you already have in your head — and where did that picture come from?"
She hadn't thought about it that way. She'd just followed the sign. But Rafa was right — she had walked in carrying an assumption about the station's layout, like a floor plan she'd drawn from memory without ever seeing the real blueprints.
"I think I assumed Central station was symmetrical? Like both platforms would mirror each other. The sign just confirmed what I already believed, even though it was pointing the wrong way."
"Every rider walks in the door carrying a wrong map. They assume the system works the way they think it should. Our job isn't just to redesign a transit system — it's to rebuild two million wrong assumptions. That's the real project."
The "wrong map" Declan describes is a mental model — each rider's internal understanding of how the transit system is organized. When the actual system contradicts these assumptions, riders don't question their model; they blame the sign, the kiosk, or themselves.
"So if we're designing for how people actually think the system works — not how it really works — we need to understand what those assumptions are first?"
Sable drew a quick sketch in her notebook — two overlapping circles labeled "what riders think" and "what actually exists." The gap between them felt enormous. It felt like the entire project lived in that gap.
1. When Sable followed the misleading transfer sign at Central, she wasn't just reading bad signage — she was navigating with a mental model, an internal picture of how the station should be organized. Her assumption that the platforms mirrored each other felt so natural that the incorrect sign seemed to confirm it rather than contradict it.
2. Declan's observation — "two million wrong assumptions" — reveals the scale of the challenge. Every rider brings their own mental model of how transit should work, built from years of prior experience with other systems. When a design matches those models, it feels intuitive. When it contradicts them, riders get lost — and usually blame themselves.
Central station sign → confirmed Sable's wrong mental model instead of correcting itThe idea that people carry internal representations of how systems work — and that design succeeds or fails based on how well it aligns with those representations — is one of the foundational insights of human-centered design thinking.