The Department of Transportation is urging those traveling during the summer to be dropped off at the airport rather than park.

Its concern is that airport parking, in particular the 4,680 stalls at the Daniel K. Inouye International Airport in Honolulu, might be filled to capacity during the busy summer season because of current construction projects and the use of parking spaces by electric vehicles, which can park at airports for free.

“We encourage people to get dropped off, whether it’s by a friend or family member or any of the companies that you can pay to drop you off,” Tim Sakahara, spokesperson for the DOT, said. “It could save people some time if they could get dropped off.”

The department had asked the public to consider being dropped off at the airport in March during spring break, yet the Honolulu airport parking lot was occasionally full.

“We did experience over that time, that travel season, that the parking lots did fill up at HNL on certain days during the peak period, and so we want people to be aware of that, that this is a possibility again for this summer,” he said.

Various construction projects are contributing to the possible summer parking shortages.

About 800 spots in the Terminal 2 parking lot are unavailable while a new car rental facility is being built. Sakahara said the facility, which is part of a larger project to modernize the airport, will be completed around the end of 2021.

One of the construction projects is for rail, which is using about 60 parking stalls, Sakahara said. That project is anticipated to last through August.

The parking issue at the airport also has become a platform to discuss the privileges of owning electric vehicles, which are effectively allowed to park at the airport for up to a month for free.

Sakahara estimated that 10% to 20% of the cars parked at the airport are EVs, a far higher ratio than what is seen in the state as a whole.

As of April, only 9,122 of the 1.08 million registered passenger vehicles in Hawaii are EVs, according to the Department of Business, Economic Development and Tourism, representing a 0.8% share.

But while current construction projects at the airport will end eventually, EVs are becoming more popular: They grew by about 29% since April 2018 and nearly 2% since March.

And as EV numbers grow, more people could start taking advantage of these parking freedoms.

A few bills to limit the parking time for EVs have been introduced over the past several years in the state Legislature, including this year, and although they have failed, they exposed concerns regarding the perks EV owners enjoy as they grow in number.

House Speaker Scott Saiki, who introduced one of those bills in 2016, said those perks don’t apply as they did when EVs were less common.

“When this legislation was initially approved, it may have been feasible at that time, but it’s no longer feasible today, because of the increase in electric vehicles,” Saiki said. “We need to consider the revenue loss to the airport division that has resulted from this benefit.”

Parking fees at the Honolulu airport are $18 per day, and monthly parking is $300. From roughly 2012 to 2017, EV owners saved a combined $2.6 million while parking at the airport, according to the DOT.

On top of free parking privileges at state and city parking lots, EV owners also can drive in the high occupancy vehicle (HOV) lanes with only one person in the car, are exempt from the state’s fuel tax and can receive a $7,500 federal tax credit for buying an EV.

EV supporters believe that the current perks are appropriate.

“In lieu of an actual rebate in the form of cash back or a tax incentive from the state, I think something like parking or access to the HOV lane is reasonable for an incentive to get people to basically change their habits and adopt a new one,” said Noreen Reimel, the communications lead for the Blue Planet Foundation.

Saiki said he doesn’t believe removing the parking privilege will deter people from buying EVs, since there are other benefits EV drivers still receive.

Act 168, which was signed into law in 2012 and includes the current parking and HOV privileges for EV, is set to end on June 30, 2020.