Growth in passenger numbers is partly driven by the arrival of two new airlines - Jetstar and Sounds Air.
On Friday 142 new secure car parks were available but Mr Story said many more were needed. It brings the total number of parks up to 682.
"On June 30 2016 we had 566,000 passengers for the year, which is where we thought we would be in 2021," he said.
To cope with increasing usage, the airport will have a total of 1000 car parks in about five years, using land originally designated for its adjoining business park.
Last year it was announced work on a new terminal would begin by the middle of this year and completed before the national kapa haka competition at the end of February next year.
That deadline will not be met, with the final design due to be presented at the end next month.
Mr Story said there were times when the car parking service level fell below expectations - at times the secure car park was completely full - and it wished to keep ahead of demand. The desired service level is for people to always be able to find a park but during busy periods may have to spend time searching.
The level of service was also about the smoothness of surface "for wheeled suitcases and high-heeled shoes".
The new car park includes improved lighting, trolley bays, 50 new baggage trolleys landscaping and wide footpaths to the terminal.
Roading company Higgins did "a wonderful job" at the secured car park and the main car park would be resurfaced in January, Mr Story said.
"In the main car park today 72 per cent of customers parked for one hour or less - the barrier arms are going up and down all day."
Occasionally the system would "fall over", he said.
"The other day there was an accident at the airport and one of the main controllers got wiped out," she said.
The driver had a cage at the back of the car which took out the entire control panel, Mr Story said.
"That control panel also had the mother board for some of the other barrier arms, creating a wide disruption."
Mr Story was tight-lipped about the airport's business park, which has had just one tenant for three years.
"We are in discussions with more than one party for more than one opportunity."
Hawke's Bay Today understands Caltex is in discussions with Napier City Council regarding a motoring service centre adjoining the airport.
The airport is due to receive a new entrance through the business park next year from Watchman Rd, part of a $9 million remodelling of the notorious State Highway 2/Meeanee Quay intersection using a roundabout.
