Fuel prices for 121 countries, food cost index & vanlife weather scores for RV travel.
OpenVan API is a free Transportation API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Details from openvan.camp.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
SNCF public API
Irish Rail planned engineering works: affected stations, DART closures, change log and ICS feeds
The OpenVan API is provided by OpenVan.camp (openvan.camp).
Yes. The OpenVan API is listed in the Transportation category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The OpenVan API requires no authentication, so you can start making requests without signing up.
Yes. The OpenVan API supports CORS, so front-end JavaScript can call it directly.
Yes. The OpenVan API is served over HTTPS, so it's safe to use in production.