Northern Ireland is compact, which changes the arithmetic of every journey. Belfast sits at the head of the lough with the M1 running south-west towards Lisburn and Newry and the M2 running north towards Antrim and Ballymena. Almost nowhere in the six counties is more than a couple of hours from the city.
There are two airports and they are very different. Belfast City sits minutes from the centre and handles domestic and short European routes; Belfast International is out past Antrim on the M2 and carries the wider network. Which one you fly from changes the collection time considerably, and the area pages carry indicative drives for both.
The ferry ports matter here in a way they do not on the mainland. Belfast and Larne both take vehicle and foot traffic to Scotland and England, and a sailing is planned exactly like a flight: the collection is set against the check-in deadline. The Antrim coast, the north coast towns and the lakes around Enniskillen add touring work on top, on roads that are scenic and slow.