Do you need a visa to transit Abu Dhabi airport?

You need transit visa only if you want to go out from the airport to the city. If you stay in airport, you will be in a transit zone without passing the boarder. In this case you no need to have transit visa.

However, for 14 hours you may see a lot of interesting things in a city. More information about visas you may find there: http://www.abudhabiairport.ae/english/airport-information/check-in-and-passport-control/immigration-and-visas.aspx

If you are a citizen of one of the following countries, you will be issued with a free-of-charge visit visa upon entry: UK, France, Italy, Germany, the Netherlands, Belgium, Luxembourg, Switzerland, Austria, Sweden, Norway, Denmark, Portugal, Ireland, Greece, Finland, Spain, Monaco, Vatican, Iceland, Andorra, San Marino, Liechtenstein, Poland, Slovenia, Slovakia, Czech Republic, Lithuania, Hungary, Latvia, Estonia, Malta, Cyprus, Croatia, Romania, Bulgaria, United States, Australia, New Zealand, Japan, Brunei, Singapore, Malaysia and Hong Kong.

I travelled in July-2017 and my transit time was 8 hrs 5 min. There was No Visa needed. I stayed inside the terminal for the entire time.

DO NOT rely on Etihad agents as some of the agents told me that I needed a Visa if my stay is more than 8 hrs.