Routehappy has developed a Score & Happiness Factors API that utilizes the company's Flightpad and Flightmatch. Flightpad is the dataset of every flight worldwide pulled from a large number of sources. Flightmatch uses algorithms to create a score covering possible flight combinations, options that number in the billions. Expedia recently partnered with the company to give consumers access to Route Happy's ranking system for trips.
As Routehappy explained, a lot goes into what makes for "happiness" when traveling:
Routehappy has created the definitive, unbiased rating system, by cabin, for every flight worldwide. Routehappy Scores are comprised of aspects of the flight experience that flyers care about most, including aircraft, seat, amenities, trip duration, and ratings. We continuously research and validate fragmented data from hundreds of sources to maintain this single authoritative measure of flight quality.
The goal is clear: create more value in flight shopping by providing a kind of fine-grained analysis that can be expressed as a measure of happiness.