How RouteWeather Works: Data Sources & Methodology

Last updated: March 2026. This page explains every data source, calculation, and logic rule behind RouteWeather's recommendations. It is regenerated automatically whenever underlying methodology changes.

What RouteWeather Does

RouteWeather is a travel decision intelligence tool. It computes the logistics, weather risk, and cost for driving a specific route — then surfaces an honest comparison of driving versus flying versus taking the train. The goal is to answer the question: "Given today's conditions, what is the safest and most cost-effective way to make this trip?"

RouteWeather is not a booking engine. It helps you decide before you book.

Data Sources

Source	What We Use It For	Refresh	Reliability
WeatherAPI.com	Current weather conditions (temperature, condition, icon, severity) at every 30-minute waypoint along the route.	Real-time, per request	High. Commercial weather API with global coverage.
OSRM (Open Source Routing Machine)	Route geometry, driving distance, and total drive time. Provides the polyline from which waypoints are interpolated.	Per request (live OSRM public API)	High for US road networks. Uses OpenStreetMap data.
Photon / Komoot	Address geocoding (text → lat/lon) and reverse geocoding (lat/lon → city name) for all inputs and route waypoints.	Per request	High for city and address-level resolution. Occasional gaps in rural areas.
AAA State Gas Price Averages	Baseline regular unleaded gasoline prices by state. Used to estimate trip fuel cost and calculate gas stop savings.	Static snapshot, updated monthly	Moderate. Reflects recent AAA-published state averages. Not real-time pump prices.
Mock Alternatives Data (Flights & Rail)	Representative flight prices (via Kayak referral) and Amtrak pricing for common corridors. These are estimates, not live fares.	Static, periodically reviewed	Indicative only. Always verify current pricing before booking.

Route Calculation Logic

When you enter an origin and destination, RouteWeather:

Geocodes both locations using the Photon API to obtain precise coordinates.
Requests the fastest driving route from the OSRM public API (driving profile, no alternatives, full polyline).
Interpolates waypoints along the polyline at every 30-minute driving interval (configurable to 15 or 60 minutes).
Reverse geocodes each waypoint to a city/municipality name using Photon.
Fetches live weather at each waypoint using WeatherAPI.
Applies gas stop injection logic: one stop suggestion every ~60 minutes of driving.
Computes trip summary: total miles, drive time, fuel cost, and weather severity.

Assumption: Routing assumes a standard gasoline vehicle at 25 MPG. EV range and diesel pricing are not currently calculated.

Weather Risk Classification

Each waypoint is given a severity label based on WeatherAPI's condition codes:

Severity	Display	Definition
Clear	✅	No weather impact on route safety. Normal driving conditions.
Caution	⚠️	Precipitation, reduced visibility, or temperatures below 32°F. Slow down; allow extra stopping distance.
Hazard	🚨	Active snow, ice, thunderstorm, or freezing rain. Delay departure or consider alternatives.

Gas Price & Savings Calculation

We use AAA's published state-average regular unleaded price as a baseline. Gas stop savings are calculated as: Discounted Price = State Average − $0.28. Savings percentage is computed as Discount / State Average × 100. Example: MN average $3.26 → stop price $2.98 → SAVE 9%.

Current AAA State Averages Used:

State	Regular Unleaded (AAA avg)	Discounted Stop Price	Savings
MN	$3.26	$2.98	SAVE 9%
ND	$3.12	$2.84	SAVE 9%
WI	$3.15	$2.87	SAVE 9%
IA	$3.18	$2.90	SAVE 9%
IL	$3.48	$3.20	SAVE 8%
WA	$3.75	$3.47	SAVE 7%
OR	$3.8	$3.52	SAVE 7%
CA	$4.52	$4.24	SAVE 6%
NV	$3.45	$3.17	SAVE 8%
CO	$3.35	$3.07	SAVE 8%

Gas stop injection interval: ~every 60 minutes of driving. Discount is a static estimate reflecting discount retailer pricing. Not a real-time pump price.

Drive vs. Fly vs. Train Logic

RouteWeather defaults to recommending driving when the route is under 6 hours and no Hazard-level weather is active. It surfaces flight alternatives when driving time exceeds 5 hours OR when a Hazard condition is detected. Amtrak alternatives are shown for corridors where Amtrak service is available (Midwest, Northeast, Pacific Coast corridors). Flight and train prices shown are representative estimates for popular routing pairs — not live fares.

Known Limitations

Gas prices: Not real-time. We use monthly AAA state averages with a static discount model.
Flight & train fares: Representative estimates only. Not live fares.
EV support: Not yet implemented. All fuel cost estimates assume a gasoline vehicle at 25 MPG.
Weather forecast horizon: WeatherAPI accuracy degrades beyond 3 days. Longer-range trip planning will show current conditions, not a 7-day forecast for future dates.
Rural geocoding: Very rural or unpaved addresses may not resolve accurately via Photon. Entering the nearest city name is recommended.

Update Frequency

Data Type	Refresh Rate
Live weather (per waypoint)	Real-time on each route request
Route geometry & drive time	Real-time on each route request (OSRM)
Gas price state averages	Monthly (manually updated from AAA)
Flight & train reference prices	Periodically reviewed (not automated)
This methodology page	Updated whenever calculation logic changes

Affiliate & Referral Disclosure
RouteWeather includes referral links to travel booking partners including Kayak, Turo, Amtrak. These links may generate revenue when used to complete a booking. Our route recommendations, weather risk scores, and comparisons are generated by our data engine and are not influenced by partner relationships. We recommend driving when it is the best option, even when doing so generates no referral revenue.