Design Competition
Mesh the Gap: Multi Modal Transportation Hub
A decentralized transit network for central Iowa, built from modular shipping container stops that scale with the neighborhoods they serve.
Overview
Iowa runs a hub and spoke transit system. Almost every trip, no matter where it starts or ends, gets routed through downtown first. That works when a city is small. It stops working fast when it is not.
Our team took that as the problem to solve. Instead of adding more buses to the same routes, we redesigned the shape of the network itself, then worked out what the physical stops would look like, what they would cost, and how a city could actually build them one piece at a time.
The short version. A trip that takes 56 stops and 2 hours 23 minutes on the current network takes 6 stops and about 15 minutes on ours. The stops themselves are repurposed shipping containers, so the network can be deployed in phases and reconfigured as neighborhoods change.
The problem
Three things pushed us toward a full redesign.
- Growth. Polk County went from 375,621 residents in 2000 to 494,281 in 2020, and is projected to pass one million by 2040. A centralized network gets worse, not better, as that happens.
- Equity. The system fails the people who depend on it most. Riders without a car, riders with disabilities, and low income riders face the longest and least direct trips, which limits access to jobs, school, and healthcare.
- Inefficiency. The average Iowa commute is 19 to 21 minutes, which is better than most states. But that number hides how badly transit riders do. Routing everything through one center turns a short trip into a long one.
Rethinking the shape of the network
We started from network topology rather than from bus routes. Hub and spoke, linear, and tree layouts all force traffic through a small number of chokepoints. A mesh does not. In a mesh, any stop can connect to several neighbors, so a rider can move across the region without ever passing through the center.
Laid over Polk County, the adaptive mesh puts a dense web of stops across the whole metro instead of concentrating service downtown. Larger community hubs anchor the network, and smaller stops fill in the space between them so no neighborhood sits outside the walking radius of a connection.
Four vehicle types carry the load. Articulated buses run the highest capacity trunk connections of one to three miles. Standard transit buses handle short to medium trips within cities. Shuttle buses and minibuses cover smaller scale demand. Ride hailing and ride sharing fill the last half mile, sending the nearest driver to a rider who requests one through the app.
The stops
The network only works if the stops match the density around them. We designed four tiers.
A stops are the largest. High capacity convenience stops that double as community space, with green space built in, seating, convenience stores, and cafes arranged in a ring around a central plaza. They are flexible by design, so a community can decide what belongs inside.
B stops sit near businesses and commercial areas and carry constant traffic to A stops and to each other. They are built from 40 by 8 shipping container modules with seating and displays, and can add extra seating, human powered vehicle rentals, or 40 by 10 modules that house small businesses.
C stops are the smallest physical stop. Kiosks placed next to neighborhoods and apartments, displaying the app so a rider can call a vehicle and move up to a larger A or B stop.
D stops are not stops at all. The D stop is the person. Through the app, a rider finds a walking or biking route to the nearest stop, or calls a vehicle directly to their location if they have a disability. It is how the network reaches people the physical infrastructure cannot.
Building it out of containers
Every physical stop is assembled from the same modular kit. A base module is a single shipping container. Modules combine to grow a stop, and the interior fit out can be customized: cafe, general retail, additional transport, convenience, bus stop, or custom tenant. The same shell serves a coffee shop in one neighborhood and a bike rental in another.
The modules carry more than shelter. Solar panels on the roof, a water reclamation system, native planting around the perimeter, electrical and mechanical systems, and space for local artists to work on the exterior. The stop is meant to be a piece of the neighborhood, not just a place to wait.
What it costs
We priced each tier from real per square foot estimates rather than guessing at a lump sum.
An A stop runs about $1,904,400 including site work, foundations, utility connections, and installation. A B stop with a cafe, seating, and bus stop comes to roughly $95,220. A C stop kiosk is about $15,500. The D stop is software: around $175,000 in app development and setup, plus hosting and maintenance each year.
Because the network is modular, none of that has to be spent at once. Stops can be added in phases without taking existing service offline, which is the difference between a proposal and something a city can actually start.
Results
The redesigned trip drops from 56 stops and 2 hours 23 minutes to 6 stops and about 15 minutes. Beyond the numbers, the network reaches riders the current system leaves out, and it grows with the population instead of straining against it.
I led a team of seven through this project, from the first concept sketches to the final boards. We presented to more than 200 industry professionals and students, and the project earned a $3,000 scholarship.
The part I keep coming back to is what the team wrote at the end of the boards: how much of the work was learning to trust other people with pieces of a design you care about, and how much better the result was for it.
The full boards
