The law has been in effect since July 1, 1998. The figures for the first six months of 1999 remain incomplete and will probably increase when the period is closed. I'm not sure why 15 year-olds were included in your piece, since they could not legally drive without supervision before the new law took effect. Even including them, there is scant improvement in highway safety after the law took effect, and what there is will probably disappear when 1999 figures are complete. In fact, the new law subjects 16 year-old drivers to the most restrictions, yet they show slight increases in crashes after the law took effect, making claims of the law's effects become more dubious still.
Causal claims require careful study.
Thus, the flat trend after the new law was adopted in 1998 represents a slowdown in the previous decline, not evidence of enhanced highway safety. These declines parallel those among California adult drivers and occurred during a period when teenagers were allowed to drive unsupervised, alone or with their peers. In fact, despite claims that there's something drastically different about teen and adult drivers, CHP figures show trends in teenage accident rates over the last 10 to 25 years are exactly the same as for adults. The image was one of teens who are hopelessly reckless unless constantly watched by adults. Thanks for your attention.