Parents and students had their first encounter with new high school start times in Fairfax County on Tuesday, leaving commuters with new traffic patterns as school buses traveled area roads during the peak of morning rush hour.

Traffic experts had expected Tuesday’s commute to be among the worst morning rush hours in years. But Fairfax school and police officials said the commute had no major issues, partly because of an enhanced messaging campaign that alerted residents and drivers about the later bell times.

“I don’t think anybody in Fairfax didn’t know that school started today and that there would be a difference,” said Fairfax Assistant Superintendent Jeff Platenberg, who oversees transportation for the nation’s 10th-largest school district.

AAA Mid-Atlantic spokesman John Townsend gave Fairfax officials credit for spreading the word early about the expected impact on traffic.

“They were expecting traffic chaos this morning,” Townsend said.

But aside from the usual hiccups normally associated with the first day of school — new drivers learning new routes, students forgetting their bus numbers — drop-off and pick-up went smoothly across the district’s 196 schools, Platenberg said.

Tamara Rollison, a spokeswoman for the Virginia Department of Transportation, said officials observed traffic backups that were fairly normal for the first day of school.

“They didn’t see anything out of the ordinary,” Rollison said. “Obviously we do see an uptick in traffic. . . . But we didn’t see anything extraordinary with the change in times with high schools going to school later.”

Peter Hesse, a father of three Fairfax County school students, sent out an ominous tweet that echoed a lot of the anxiety over Tuesday’s commute: “Thanks to the new later start times for high school, today might be the worst commute ever for Fairfax County.”

But Hesse, who commutes just four miles from Oak Hill to Reston along Centreville Road, said he was pleasantly surprised. His commute took about the same amount of time as it usually would — approximately 15 minutes.

“I expected it to be worse for me,” Hesse said.

School Board member Ryan McElveen (At Large) captured the anticipation that parents and students experienced in traffic on the way to classes.

“Be careful out there,” McElveen tweeted. “Roads are filled with school buses and the tears of #FCPS students. Happy first day of school!”

The Fairfax County School Board voted last fall to push back high school start times to help teenagers get more sleep. Under the new bell schedules, high school classes begin between 8 a.m. and 8:10 a.m. Last year, the first class started at 7:20 a.m.

More than 130,000 Fairfax County students ride the school system’s 1,610 buses. Fairfax claims a bus fleet larger than Greyhound, moving more children back and forth than all school districts in the country except for New York City.

The plan to push back start times in high school came after a decades-long effort to help improve teen health. Last year, the school board commissioned experts at Children’s National Medical Center to provide data and a strategy for the administration to implement later start times. The physicians and experts from Children’s Hospital said that teens need at least nine hours of rest to promote health and wellness.

But starting school later also means that student drivers, parents and buses will be on the roads at the height of morning and afternoon rush hours in Fairfax, which is home to 188,000 students and more than 1 million residents.

Stuart High School Senior Tamara Ferrufino, 17, was among the last students to trickle into her school Tuesday morning. She had trouble finding parking, ultimately squeezing her green sedan, carefully, into a tight parallel spot.

Pleased with her parking job, Tamara, a cheerleading team captain, stopped on the sidewalk to snap a picture on her phone before walking toward the building. She said she felt energized, having slept a bit later because of the new start times.

“I feel a lot more awake,” she said. “Last year I overslept a lot, staying up late finishing assignments.”

Chantilly High School student Gionathan Vilone said he worries about missing out on extracurricular activities because the later start times also mean school will end later. Between all of his homework for his Advanced Placement classes, he said, he’s not sure there will be time for much else at the end of the day.

“Last year, I played soccer,” Vilone said. “I don’t think I’ll have time for it this year.”