Traffic chaos has overshadowed the inaugural Balmoral Show at the Maze after heavy congestion left thousands of motorists facing lengthy delays.
Queues stretching for miles meant some drivers trying to access the former paramilitary prison site on the outskirts of Lisburn had to wait for more than two hours to reach the car park.
Organisers had urged the 80,000 visitors due to attend the annual three-day agricultural festival to make use of public transport, including a shuttle bus service from Lisburn train station.
Ulster Unionist MLA Tom Elliott, who drove from Enniskillen with his wife and two children, said the traffic jams meant they arrived two-and-a-half hours later than expected. Mr Elliott said: "I have never witnessed anything like that for an international event. Cars were bumper to bumper for a mile-and-a-half before the Moira turn-off. It was very frustrating."
It is the first time in more than 100 years that the Balmoral Show has been held outside Belfast. Members of the Royal Ulster Agricultural Society (RUAS) - which runs the event - voted to relocate from their previous home at the King's Hall complex last June.
First Minister Peter Robinson, who attended the show opening, said he hoped traffic problems could be overcome. "We'll look at what happens in the next couple of days and look at the possibility of doing something that might take away some of the difficulties that occur this year," said Mr Robinson.
A new direct junction linking the 65-acre site to the M1 will not be built until 2015. Motorists accessing the show via Sprucefield and the Blaris Road did not experience the same difficulties as those travelling from the west along the Moira Road.
"There are have been delays today accessing Balmoral Park. We would ask visitors to follow the directions of the PSNI and digital signage as they make their way to the Balmoral Show. If visitors are planning to attend the event we would encourage them to avoid peak periods," said RUAS chief executive Colin McDonald.
Organisers said a traffic management plan had been put in place after consultation with statutory bodies such as the Department of Regional Development, Lisburn Council, the PSNI and Translink. Predicted traffic flow was analysed at length and a number of measures were put in operation in an effort to alleviate delays. There was no planned one-way system but PSNI officers were deployed to various locations to direct traffic.
Prince Edward, who is patron of the RUAS, officially opened the new showgrounds. He spoke to officials and local politicians who were among a welcoming line-up.