The main driver’s license center at Kapalama Hale will start opening Saturday mornings to handle a surge in the number of renewals.

After a change in state law in 2008, the expiration date for most Hawaii driver’s licenses was extended from every six years to every eight years.

The two-year extensions are now causing a jump in the number of renewals, prompting the City and County of Honolulu to take steps to handle the influx by extending hours and turning to an online system to handle requests for duplicate licenses.

“What is happening is these (licenses) are expiring in huge numbers,” Mayor Kirk Caldwell said at a news conference Tuesday.

In 2016 the city serviced about 1,000 license renewals monthly, Caldwell said. During the first nine months of 2017, the number of renewals climbed to 9,500 a month.

Beginning this Saturday, the Kapalama Hale driver’s license center will be open from 8 a.m. to noon Saturdays, in addition to its regular Monday-Friday schedule, as part of a pilot project that likely will run until the end of the year. The sixth-day service will be available only to those seeking license renewals, so there will be no road testing or written exams.

Motorists can renew a license up to six months before the deadline on a driver’s license and maintain the same expiration date, Customer Services Director Sheri Kajiwara said.

In another effort to reduce lines, Oahu motorists may apply for duplicate licenses or instruction permits using their mobile devices or computers. To do so, go to ­license.honolulu.gov. The only caveat is a motorist would not be able to change an address, name or other information online, city officials said.

Temporary paper licenses or permits will be mailed to applicants within two to three business days, with more permanent licenses or permits sent in two to three weeks.

The city encourages the public to use online services as much as possible. Go to honolulu.gov/csd.