Miller told frustrated lawmakers that the state's hands were tied. He said changes to the requirements could come only on the federal level.
"Probably our biggest challenge was the documentation," DMV spokeswoman Natalie Harvey said. "That's what we heard the most from folks."
Harvey said many residents seem to be getting used to the requirements, though.
The DMV processes about 400,000 applications for new licenses or renewals each year. As of Monday, about 40 percent of all state driver's licenses had been issued according to Real ID guidelines, according to agency data.
"We are thrilled with the progress we've made," Harvey said.
The deadline for compliance has been extended twice, and it could be extended again.
Most states aren't expected to comply by the deadline.
More than a dozen states have enacted laws opposing compliance with Real ID and several others have approved resolutions opposing it.
A study by NCSL, the National Governors Association and the American Association of Motor Vehicle Administrators estimated the Real ID program will cost states $11 billion over five years. In 2008, the U.S. Department of Homeland Security estimated the cost at no more than $3.9 billion.