Topeka ? Matthew Lee’s fourth birthday is today, inspiring thoughts of the cool Batman stuff he could receive as presents. In Kansas, reaching age 4 also has meant a child could shed the special vehicle safety seat on car trips.

But that will change Saturday, when a new law takes effect requiring children aged 4 through 7 to ride in booster seats. Kansas joins a growing number of states enacting such laws in recent years, driven by research showing seat belts made for adults don’t protect young children in crashes.

Matthew’s mother, Stephanie Lee, is ready for the new law. She’s already consulted with his pediatrician about whether he’s ready for a booster seat, and the boy is. She has no problem with the state’s new rule.

“I think it’s a good idea,” she said during a shopping trip to a local Wal-Mart. “A lot of kids roam around cars, and I know it’s not safe.”

Fines to triple

Thirty-seven states and the District of Columbia have enacted booster seat laws since 2000, according to the National Highway Traffic Safety Administration. Kansas did this spring, and Missouri Gov. Matt Blunt planned to sign booster seat legislation today.

Kansas already had a law requiring children younger than 4 to ride in safety seats and mandating that children aged 4 through 13 – as well as any driver or front-seat passengers – wear seat belts. The new booster seat requirement will apply when a child aged 4 through 7 weighs less than 80 pounds or is shorter than 4 feet 9 inches.

Through June 30, 2007, drivers who don’t comply with the law will receive a warning ticket. After that, the fine will be $60, triple the old fine.

Even with the old seat belt requirement, 161 children ages 4 through 13 died in traffic accidents in Kansas from 1995 through 2005, according to the Kansas Department of Transportation. Only 49 were even wearing seat belts, KDOT said.

Booster seats save lives

Advocates of the new law said if belts don’t fit – and they don’t with young children – riders often put the shoulder belt behind their backs or under their arms. Young children often scoot forward on the seat, so that their knees can bend. Frustrated parents and children often give up on using belts altogether.

And even opponents of the law don’t question whether booster seats save lives and prevent serious injuries.

House Transportation Committee Chairman Gary Hayzlett uses a seat belt, as do his grandchildren. But he fought the new mandate and said his constituents laugh in wonder at how much state government is willing to intrude into their lives.

There also were concerns about how a mandate would affect large families, though booster seats at Wal-Mart can cost less than $15, and state and local officials and groups have programs to help poor parents.

“Parents have to have some responsibility,” said Hayzlett, R-Lakin. “This is just stepping closer and closer to saying, ‘We’re just going to have to tell you everything you have to do in life.”‘

Many agree with law

However, even some Kansans who dislike the seat-belt requirement for adults don’t have a problem with the new law.

Topeka resident Roberta Hughes said when she buckles up, the shoulder belt often rubs uncomfortably against her neck. She believes that as an adult, she ought to be allowed to make her own decisions about her safety and that, “If God’s going to take me, he’s not going to worry if I wear a seat belt.”

But her grandchildren and other kids are different.

“They’re thrown around easier than I am,” she said.

Only in recent years has reliable data emerged on young children and vehicle crashes.

Safety advocates thought they’d protected young children with seat-belt laws, starting with Tennessee’s in 1978, continuing until all states had something by the late 1980s.

Deaths increase

Then, in the 1990s, emergency rooms began seeing children die from crash injuries after riding in the front seat when air bags deployed. That led to increased general interest in child passenger safety, said Dr. Dennis Durbin, a pediatric emergency physician at the Children’s Hospital of Philadelphia and co-director of a research project also involving State Farm Insurance Cos.

He and other advocates said the same injuries – head and neck trauma, crushed spleens, damaged livers and perforated intestines – occurred often enough in young children that doctors and nurses gave them a name, “Seat-belt syndrome.”

“We couldn’t answer some very basic questions about children’s experiences in motor vehicle crashes,” he said.

In 2003, research from Durbin’s project found that for every 100 children using seat belts and injured in a crash, booster seats would have prevented 59 injuries.

The push for a booster seat law in Kansas began in 2001, but legislation died four times in the House – in part because of Hayzlett’s opposition. But as testimony from doctors and safety advocates continued and data piled up, legislative resistance weakened.