About the Algorithm

RopeDrop is not another Disney blog. It's a real optimization engine — vehicle routing with time windows, a three-layer wait-time prediction model, and a strategy engine fed by millions of measurements from the parks themselves.

7.7M+
Wait-time samples
6
Disney destinations
10
Parks modelled
5-sec
Solver time budget

The Routing Engine — Google OR-Tools VRP

Under the hood, RopeDrop's trip planner frames your Disney day as a Vehicle Routing Problem with Time Windows (VRPTW) — the same class of problem Amazon and UPS solve to route delivery trucks. Our "vehicles" are sub-groups in your party; our "stops" are the rides, shows, and dining reservations you want to hit.

What the solver handles

  • Multi-vehicle splits: 1 – 4 sub-groups, each with its own walking speed (e.g. 0.85× for stroller / ECV groups).
  • Fixed reservations: dining bookings get a ±15 minute time window; the solver routes around them.
  • Drop penalties: low-priority attractions can be dropped rather than forcing a bad route — penalty scales with your group's consensus score.
  • Walking distance: built from a NetworkX graph of park walkways, with Dijkstra shortest paths and a Haversine × 1.4 fallback for disconnected segments.
  • Service times: wait + ride duration per stop. Rides default 20 min, restaurants 60 min, reservations 90 min.
  • Search: PATH_CHEAPEST_ARC first solution plus GUIDED_LOCAL_SEARCH metaheuristic, capped at a 5-second solver budget so your itinerary lands instantly.

The Prediction Engine — Three Layers, Weighted

Every wait-time prediction RopeDrop shows is the product of three signals, weighted together:

Layer 1 — Recency-weighted day-of-week baseline

For each ride, we average historical waits for the target day-of-week with exponential recency weighting — last week's Saturday counts more than last year's.

Layer 2 — Trailing momentum

We compare the 7-day trailing average to the 30-day trailing average and clamp the multiplier to [0.80, 1.30]. If a ride is trending up heading into your day, the prediction follows.

Layer 3 — Seasonal calendar

A multiplier for holiday periods (Spring Break, Christmas, Jersey Week, F&W Festival, etc.), capped at 1.40×. Built from year-over-year comparison of the same calendar dates.

The three multiplications are combined, floored at a realistic minimum wait, and logged alongside their metadata so every prediction is auditable.

The Strategy Engine

Routing and predictions answer what to do. The strategy engine answers when. It runs five analyses over the prediction output:

Where the Data Comes From

Wait times are collected every five minutes from a data pipeline that writes into a Postgres warehouse. Over 7.7 million samples have been logged across the six Disney destinations. Weather, temperature, sellout behaviour, downtime, and park hours are joined in at analysis time. The same data powers the public data API and the analysis pages (cascade maps, weather impact, reliability index, and more).

Why This Exists

Most Disney planning sites republish the same advice. RopeDrop was built to do the opposite: ingest measurements, solve the routing problem properly, and surface the output as plain-English picks. If a tip can't be justified by the data, it doesn't ship.

ZC
Zachary Campione Founder & engineer. Built RopeDrop solo — FastAPI backend, OR-Tools solver, prediction engine, and the data pipeline behind every wait-time call. More about the project →