Terence Brannigan, chair of the Maze/Long Kesh development Corporation, was speaking after roads around the former prison site were congested on the first day of the event.
Mr Brannigan said rural roads were "not designed for that kind of traffic"
But he said work was under way to put the new infrastructure in place.
"In 12 months time it won't be the same," he said. "But let's not pretend that in 12 months time we are going to have two roads linking up to the motorway network.
"The work is going on now, as we speak,  in respect of putting two links into the motorway, one from the east and one from the west.
"We are doing environmental studies now in order to get clearance. We will then have to go to planning and from that we will then be able to build the two roads."
Up to 80,000 people are expected to attend the three-day event, which has moved from its previous home at the King's Hall in Belfast.
On Wednesday, First Minister Peter Robinson said he hoped any problems with access would be overcome.
Mr Brannigan said getting the infrastructure sorted had been a priority for the corporation, but acknowledged there was a  "rigorous process" to complete.
"If people have to sit in queues for a long period of time, it can spoil what is a magnificent show, a fantastic event and the showcase for Northern Ireland," he said.
"The money has been ring-fenced so we can't complain that we haven't got the money, we can't complain that we are not getting the support.
"But there is a due process we have to go through.  It is frustrating, nonetheless it is a process we must go through."
Visitors to this year's show have been urged to use public transport.
The Balmoral Show website contains details of how to get to the show by car or by public transport.

The events were organised by the Right2Water group.
RTÃ‰ reports that demonstrations were held in various parts of the country including Dublin, Cork and Galway.
The Right2Water campaign is made up of community groups, political groupings and trade unions.
Brendan Ogle of the Unite trade union said the demonstrations were the first step in a significant pre-election campaign by Right2Water.
"Water has been a catalyst in the fight against austerity but people are crying out for a change in how our country is run and that will be visible on the streets of Dublin, Cork, Limerick, Galway and Donegal, among other counties today," he said.
The Irish Department of the Environment said three out of four people are now paying water bills.
This figure includes those on private schemes as well as those paying through Irish Water.
The department added that it did not think it prudent to advise people to get into debt by not paying their bills and urged them to engage with Irish Water.
About £20m has been pledged to construct two major roads linking the new site of Balmoral Show to the motorway network, it has been claimed.
[NEXT_CONCEPT]
Thousands of people in the Republic of Ireland have participated in 30 demonstrations about water charges.