(CNN) - Parents make significant mistakes when using car seats and boosters for children with a full 20 percent failing to read instructions on how to properly install safety restraints, a survey showed on Monday.
Preliminary results were released by the National Highway Traffic Safety Administration to kick off Child Passenger Safety Week and to remind parents and caregivers about steps that could prevent injuries and deaths in accidents.
"The key to keeping kids safe is to make sure your child is in the right seat for their age and size and to make sure the seat is correctly installed in your vehicle," Transportation Secretary Ray LaHood said in a statement.
Car crashes are the leading killer of children 1 to 12 years old in the United States, NHTSA figures show.
As part of the survey, the safety agency interviewed more than 4,000 drivers and conducted random inspections at 24 locations nationwide between June and August last year.
Although 20 percent of all drivers of child passengers surveyed admitted that they did not read the instructions for properly installing child seats, the research found that respondents overall were comfortable with safety.
"(Ninety) percent of them said that they were 'confident' or 'very confident' that their child restraint systems were installed correctly and the children seated correctly," the survey found.
Still, transportation officials expressed concern that highly confident drivers who misuse the restraints will not seek out information about proper procedures.
NHTSA detailed the five-most significant mistakes observed during the study of car and booster seats:
-- Wrong harness slot used
-- Improper harness retainer/chest clip position
-- Loose child restraint system installation
-- Loose harness strap
-- Improper lap belt placement
Safety officials recommend that children under age 1 should always ride in a rear-facing car seat. Between the ages of 1 to 3, children should remain in a rear-facing car seat until they reach the top height or weight limit allowed by the car seats' manufacturer.
Once they have outgrown the rear-facing car seat, they are ready to travel in a forward-facing car seat with a harness. Children 4 to 7 should be in forward-facing car seats with a harness until they reach certain weight and height limits.
From 8 to 12, they are in booster seats until they are big enough to use seat belts.
Transportation officials suggest all children under the age of 13 ride in the back seat.