Teaching assistant Leonardo Baker, left, greets students arriving at Franklin High School in Seattle in this Dec. 12, 2018, file photo. The Seattle School District changed from a 7:50 a.m. start time to 8:45 a.m. in the fall of 2016 for high schools and most middle schools, joining dozens of other U.S. school districts adopting later starts to fight teen sleep deprivation. Credit: Elaine Thompson | AP

The evidence is clear: Starting schools, especially high and middle school, later in the morning is better for the education, health and safety of teenagers.

Based on this evidence, California became the first state in the nation to mandate that public high schools begin no earlier than 8:30 a.m. Last week, Gov. Gavin Newsom signed the new law, which gives schools until July 1, 2021, to adjust their start times.

“This is huge,” Judith Owens, a neurology professor at Harvard Medical School, told NBC News about the California move. Owens was the lead author of a 2014 policy statement from the American Academy of Pediatrics that called for later school start times to improve academic performance, improve the physical and mental health of students and reduce car crashes.

In 2017, Maine lawmakers considered a bill to require that high schools not start before 8:30 a.m. and that extracurricular activities ended by 7:30 p.m. The bill was rejected by lawmakers.

We understand the concerns, expressed by the state’s associations of superintendents and principals, that school start times and extracurricular activities are best set at the local level. We also appreciate that starting school later could require changes in bus and extracurricular activities schedules, and that this could lead to additional costs.

However, given the science behind the benefits of later school start times, a slow, district-by-district approach is not in the best interests of Maine’s teenagers.

Starting school at 8:30 or later would ultimately save $9 billion a year, a recent study by the Rand Corp. found. The savings would come from improved student academic achievement (which lead to higher lifetime earnings) and a reduction in car crashes. These savings would far outweigh the costs of adjusting bus schedules and changes to infrastructure, such as adding lights to sports venues, the report found.

Fewer than 11 percent of public high schools in the U.S. start at 8:30 or later. Several Maine school districts, including Portland and South Portland, have adopted later school start times.

Nearly three-quarters of high school students in the U.S. do not get enough sleep, the Centers for Disease Control and Prevention has concluded, based on a 2015 survey of student behaviors. Teens between the ages of 13 and 18 should sleep for 8 to 10 hours per night, the CDC recommends.

“Insufficient sleep among children and adolescents is associated with an increased risk for obesity, diabetes, injuries, poor mental health, attention and behavior problems, and poor academic performance,” the CDC said in 2018.

A study of first-year students at the U.S. Air Force Academy found that students performed better in all their classes, throughout the day, if their school day started later.

“With schools aiming to improve student achievement while simultaneously facing large budget cuts, determining the impact of school start time has important implications for education policy,” the researchers, from the University of California at Davis and the Air Force Academy, wrote. “Our findings suggest that pushing back the time at which the school day starts would likely result in significant achievement gains for adolescents.”

Outside of school, motor vehicle crashes are the leading cause of death among teenagers. More than a quarter of car crashes attributed to sleepy drivers involve teens, even though they represent less than 7 percent of the U.S. population.

Starting school later can help in this regard, too. For example, when one Wyoming high school moved its start time from 7:35 to 8:55 a.m., crashes involving teen drivers dropped by 70 percent.

Certainly, other factors beyond the length of the school day affect how much sleep students get at night. Homework, a job, hanging out with friends, video games, social media and other activities can cause students to stay up late. These can all impact school performance and other aspects of their lives.

But, with clear evidence that starting school later than 8:30 can improve student’s learning, their health and their safety, later school start times are worth a close examination in Maine.

The BDN Editorial Board

The Bangor Daily News editorial board members are Publisher Richard J. Warren, Editorial Page Editor Susan Young, Assistant Editorial Page Editor Matt Junker and BDN President Todd Benoit. Young has worked...