The past 12 months proved to be a ripe year for travel stories and trends. So much so that it has made condensing them down into five highlights somewhat tricky.

We're not complaining, though, as it acts as evidence that the travel industry is flourishing and makes the year ahead that bit more exciting.

So here are the trends and stories that stayed with us through into the New Year – some of which may well rumble on into 2016 and beyond:

Airbnb expansion

It's been quite a year for Airbnb. In the first quarter of 2015, it emerged that the short-term rental service owed the City of San Francisco $25 million in back taxes and penalties for failing to collect hotel taxes, spanning back several years.

However, once it put that matter behind it – paying the city the amount "in full" – it pressed ahead with its expansion, which, in 2015, comprised wooing business travellers. In the 12 months after its launch, Airbnb's business travel program had grown by 700%. It appears that companies are recognising the money they can save by having workers stay together in the same apartment while on a business trip.

Immersive experiences

Emerging as a trend at the start of the decade, immersive travel really took off in 2015. Travellers are no longer satisfied with merely exploring destinations such as Peru, Cambodia and Vietnam – they want to live it and see the countries for what they truly are. We'll be sure to revisit this trend throughout 2016.

Doppelgangers go viral

Imagine you board a flight only for the person seated next to you to be a spitting image of yourself. That's what happened to Glaswegian photographer Neil Thomas Douglas – a chance meeting that spawned many other stories of doppelgangers bumping into to one another and got everybody thinking: "Does everyone have a doppelganger?"

What was even more remarkable about Douglas and his lookalike was that they had both sculpted their beards to the same length – what are the chances?

Knee-to-knee travel

How happy would you be with being seated face-to-face with your fellow air passengers? We ask because 2015 saw the emergence of a new concept for the air cabin seat, with passengers seated knee-to-knee.

Designer of the concept, Zodiac Aerospace, says the HD-31 will create more space and make air travel more comfortable for travellers. However, airlines will likely need more convincing than that for the concept to be widely adopted in 2016.

Digital bookings forever rising

Mobile booking, once a novelty and niche behaviour amongst travellers, continued to go from strength to strength in 2015. In fact, data shows that digital and mobile bookings are helping North American hotels offset declining reservation pace to improve their average daily rate performance.

It's set to be a similar story in 2016, with some forecasts predicting that over half of all digital travel purchases will be via mobile by the end of the year. Let's hope travel firms are ready for this shift in buying habits.