Data sources
RoadRange's maps and tools are built on open, public data. We sync each source from its official provider on a regular schedule, so we stay within their usage terms and limits. Every source we use is listed below, along with what it provides and the attribution and licensing terms we honour.
National parks — U.S. National Park Service
Park units (parks, monuments, historic sites and more) and the states they sit in come from the National Park Service (NPS) Data API.
Source: U.S. National Park Service, nps.gov/subjects/developer. NPS asks that the data be attributed; see the API documentation and terms. NPS-authored content is generally in the public domain.
Scenic byways — U.S. DOT / Federal Highway Administration
The routes behind the scenic byways map — America's Byways, i.e. every National Scenic Byway and All-American Road — come from the Federal Highway Administration's National Scenic Byways geospatial service. We mirror the route geometry, name and designation, and derive the states each byway runs through from its geometry.
Source: U.S. Department of Transportation, Federal Highway Administration, US_Scenic_Byways feature service (see the National Scenic Byways program). Data produced by a U.S. government agency are in the public domain.
Fuel prices — U.S. Energy Information Administration
Retail gasoline and diesel prices behind the fuel-price map come from the U.S. Energy Information Administration (EIA) APIv2: weekly retail prices from petroleum/pri/gnd (USD/gal) and annual figures from SEDS (USD/MMBtu).
Source: U.S. Energy Information Administration (EIA), eia.gov/opendata. EIA data are in the public domain; attribution is requested. See the API terms & documentation and copyright & reuse policy.
Currency exchange rates — European Central Bank
The optional currency conversion on the fuel-price map — showing fuel prices per litre and in your own currency — uses the European Central Bank's euro foreign-exchange reference rates. We read them through the open-source Frankfurter API (its current v2 endpoint, pinned to the ECB provider) and mirror them into our own database on a schedule.
These are the only conversion inputs that come from an outside source. The per-litre figure and any non-USD amount are computed by RoadRange, not published by the ECB or EIA — we label them as our interpretation wherever they appear.
Source: European Central Bank, euro reference exchange rates, served via Frankfurter (source). ECB reference rates are published once per working day (~16:00 CET) and are indicative — explicitly not intended for transactions; see the ECB's disclaimer and terms.
Airports — OurAirports
The major airports behind the airports map come from OurAirports, a community-run open database. We show large and medium airports flagged with scheduled service and an IATA code.
Source: OurAirports. The data are dedicated to the public domain; see ourairports.com/data.
Driver handbooks — state licensing agencies
Every state page links to that state's official driver handbook, published by its driver-licensing agency (DMV, DOT, Department of Public Safety or equivalent). Unlike our other datasets we don't mirror these — we keep a hand-checked list of links straight to each agency's own handbook page.
Source: the individual U.S. state and District of Columbia licensing agencies. Driver handbooks are official government publications; each link points to the issuing agency's own site, where its terms apply.
Traffic rules — state handbooks, IIHS & GHSA
The per-state traffic-rules panel on each state page — the top posted speed limit, seat-belt enforcement, hand-held-phone rule and DUI limit — is a hand-curated summary. Each figure is confirmed against that state's official driver handbook, and the comparative classifications follow the state-law tables published by the Insurance Institute for Highway Safety (IIHS) and the Governors Highway Safety Association (GHSA). Our US traffic-rules guide cites the underlying federal sources.
Sources: the individual U.S. state and District of Columbia driver handbooks (official government publications; see Driver handbooks above), IIHS and GHSA. Laws change; each state page links to the issuing agency's own handbook, where its terms apply.
Weather — NOAA / National Weather Service
The current temperature and conditions behind the current-weather map come from the U.S. National Weather Service (NWS) web API. Unlike our other sources, weather is time-sensitive, so we read it live (one observation station per state capital) and cache each response briefly rather than mirroring it into our database — the API is only called when someone opens the map after the cache lapses.
Source: U.S. National Weather Service, weather.gov web API. NWS data are produced by a U.S. government agency and are in the public domain; see the NWS disclaimer.
State boundaries — Natural Earth
The US state shapes drawn on every map come from Natural Earth, packaged as TopoJSON in the us-atlas project.
Source: Natural Earth. Natural Earth data are in the public domain; the us-atlas package is released under the ISC licence.
Maps are rendered with D3 and TopoJSON, open-source libraries under the ISC and BSD licences. These are software tools, not data sources.