The law, which was passed in 2006, doubles the required amount of time behind the wheel from 20 hours.
It's too early to see the impact of the law on teens' driving, said Debbie Burton, chief driver examiner for Troop E. But, she can't foresee any drawbacks.
"The more experience they can get behind the wheel, the better driver they're going to be," Burton said.
The 10 hours of nighttime driving is a good move. "It's a whole different experience (driving at night)," she said.
Mike Right, vice president of public affairs for Missouri AAA, agreed. "Frankly, the most serious crashes occur at night," he said. Driving techniques and visual clues vary between night and day, he added.
Parents play a big role in enforcing the law, as they verify the requirement has been met. "There is a paper the parent or guardian signs saying the individual has completed that many hours," said Dawn Collier, office manager at the Sikeston License Bureau.
Burton said the time factor may be a challenge for some parents. "They may ask 'where am I going to find the time?'" she said.
But that actually isn't a lot, given the time frame. "In six months, it wouldn't take that long," said Morgan Ahart, 16, of Benton .
Morgan would probably accumulate 40 or more hours of driving in different situations regardless of the law, said her mother, Daphne Swope.
But, all novice drivers may not be held to that. "Some parents, regardless of the law, aren't going to abide by it," she said. "Because who is going to know?"
Right said that is an isolated problem. "I think most parents are indeed responsible in seeing that their youngsters learn properly a life skill," he said.
The increased requirement is a move in the right direction, but still low, Right said. "Learning to drive takes time, maturity, practice and experience," he said, pointing out that motor vehicle accidents are the top cause of death for young people in the nation.
"Missouri is behind some of the more restrictive state in the nation," Right continued. Some states require 50 hours of instruction plus the completion of a high school drivers education program.
Such a program is not currently required in Missouri. However, some summer courses are offered.
Fred Johnson, one of the drivers education instructor for the course Sikeston Public Schools offers, said the law will not affect what the program teaches and requires. He and other instructors will, however, inform students and parents of the new requirement.
Johnson, too, can only see a positive outcome to the law. "I can't see where it would hurt," he said. "I don't think you can give them enough instruction."