The loose metal strewn on the road was coarse, she said, and constantly banged against their car.
Mrs Pike said her grandson would face a large bill to have his car fixed because large chips got into the wheels.
"He did all the right things to release them but to no avail and the noise when driving later was horrific. Definitely some damage was done," she said.
"Next day we went over the same stretch of road and the work was being managed the way it should have been the day before."
Traffic started building up at the Portland Rd turnoff and Ms Pike said motorists could have got out and walked, which could have been quicker.
"The warning signs were missing. Nobody at the end line of traffic was reporting what lay ahead. The intensity, flow and closeness of traffic flow required better management."
NZTA has ruled out paying for damage to vehicles and said some drivers may have sped through roadworks despite appropriate speed restrictions.
The agency's Auckland and North highway manager Mieszko Iwaskow said work started on Tuesday on Mountain Rd north of Kaiwaka and there were others scheduled to start later this week on SH1, 290m south of Totara Rd. Throughout January, he said the agency would proactively plan works to minimise impact for road users.
"This will include not undertaking works at known hot spots during busy periods and providing communication to customers through forums such as the summer season website www.nzta.govt.nz/summerseason."