A few interactive models I've put together to help make transportation tradeoffs a little easier to see, whether that's in a classroom, a workshop, or the rooms where these decisions get made.
I've developed the following interactive exercises as a way to visually communicate some transportation concepts and ideas. While these are all teaching tools (with some clear underlying assumptions), they can be used for various audiences. Change the inputs and watch the tradeoff play out live. These all continue to be a work in progress, so I welcome any feedback or suggested changes.
Roundabouts come up often in conversations about intersection safety, and I've found it helps to actually see why. A four-leg intersection and a single-lane compact roundabout sit side by side, and you can follow one trip through each and count where it meets other traffic. The intersection has 32 conflict points and the roundabout has 8, none of them crossings. A second view looks at how people biking and walking fit in, with research from Flanders and examples from Cambridge, UK and Bend, Oregon.
Open the model → Bike parkingMost bike parking is still designed around one size of bike, and I think it helps to see what that means for someone arriving on a longtail or a cargo bike. Here a typical bike, a longtail and a front-loader each take a turn at the comb, wave and staple racks, all drawn to scale and checked the way a plan reviewer would. I've also included APBP's spacing guidance and a few notes on how Portland and Durham are starting to plan for cargo bikes.
Open the model → Transit service planningEvery bus schedule comes down to the same equation: how long one round trip takes, divided by how often you'd like a bus to come. You can adjust route length, speed, layover and frequency, and watch the fleet requirement and the operating budget move along with them. A second view puts a fixed fleet against a whole town, which I've found is a helpful way to work through the ridership and coverage tradeoff.
Open the model → Curb pricingOne blockface, 24 metered spaces, and a garage around the corner at $5.00 an hour. Move the curb price and see what happens to the drivers who can't find a space. The queue circling in the travel lane isn't animation for effect, it's what the price produces. I've also included what the research says about how much cruising cities actually see, since the evidence there is more mixed than you might expect.
Open the model → Parking requirementsA 66-acre downtown core, 96 parcels, and eighty years. No parcel is cleared by hand here. Each redevelopment simply solves the equation the zoning code sets, which is to fit a building and its required parking onto a single lot, and the crater is what that equation returns. You can change the requirement and run it again.
Open the model → Freeway operationsTwo identical ring freeways, eight interchanges each, and exactly the same drivers trying to get on. One lets everyone on and the other meters its on-ramps. Raise the demand and you can watch the open ring hit a tipping point where fewer cars reach their exits, while the metered ring keeps moving. It's based on Carlos Daganzo's research on freeway gridlock, and I've added a few notes on Minnesota's ramp meter study and I-285 here in Atlanta for some real-world context.
Open the model →These were built for teaching, but they work just as well in a council work session, a staff workshop, or a stakeholder meeting where the same argument keeps going in circles. Please feel free to use these tools and if you'd like to brainstorm with me further, please feel free to reach out!
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