A nationwide shortage of bus drivers means routes are being eliminated, walking boundaries are being expanded and students are facing longer travel and wait times.

The big picture: About 88% of schools are dealing with bus driver shortages, according to a survey from HopSkipDrive, a school ride-service company.

• The top reasons for the shortage are recruiting issues, pay and retirements.

Why it matters: A lack of reliable transportation to school can impact student attendance. About 67% of schools said they believe there's a direct link between the two, and 61% reported having issues with chronic absenteeism, according to HopSkipDrive.

More than 450 bus drivers are needed in Michigan ahead of the first week for many districts, Katrina Morris, executive director for the Michigan Association for Pupil Transportation, told Axios.

• "That's over 18,000 kids," Morris said. "How are they going to get to school?"

North Carolina's largest school district, Wake County Public Schools in Raleigh, will have 52 fewer bus routes compared to last year. That could increase if more positions aren't filled soon.

• Other districts have reduced routes, including some from Maryland, Maine and Alaska, where one district requested help from the National Guard.

In Seattle, administrators are encouraging parents to take advantage of a new fare-free public transit program that will let people 18 and under ride buses and trains for free in King County.

In Chicago, special education students have seen travel times exceed 90 minutes, as the district still has hundreds of bus driver openings to fill.

Flashback: Schools have been struggling to find bus drivers for years, even before the pandemic.

• In a survey conducted by the National Association of Pupil Transportation in 2016, 87% of respondents said the bus driver shortage was a major problem, and 70% said it was only getting worse.

State of play: School boards have been bumping bus driver salaries and offering incentives.

• Wake County's school board has proposed paying $17.20 per hour with a sign-on bonus of $1,200 and giving existing drivers a retention bonus of $1,250.
• Columbus City Schools offered bonuses of up to $2,000 for bus drivers last year.

The intrigue: The pay boost is helping, at least in some districts.

• In Northwest Arkansas, districts increased starting pay and optimized routes and only had a handful of openings this year, compared to last year when principals and administrators pursued commercial driver's licenses so they could drive buses.
• In Austin Independent School District, which also recently increased driver pay, a spokesperson told Axios all regular routes are covered and the district is not having any problems.

What we're watching: Joanna McFarland, CEO and co-founder of HopSkipDrive, told Axios she thinks using smaller vehicles to transport students to school would make the system more efficient.

• A new law in Arizona will allow districts to use smaller vehicles that carry between 11 and 15 people to transport students, meaning drivers won't need to hold a commercial driver's license.
• Removing that requirement may make it easier to recruit drivers.
• "Drivers with a CDL are in high demand, and we're losing them to big companies like Amazon and Fed Ex," Arizona state Sen. Sine Kerr said in a statement.

The bottom line: Higher pay hasn't solved the problem everywhere.

• Cobb County School District near Atlanta is facing a shortage of 200 bus drivers, even after awarding $1,200 bonuses last year.
• Denver schools raised pay and dropped a vaccine mandate but still had dozens of open positions leading up to the school year.

Axios reporter Erin Doherty and Axios Local reporters Jessica Boehm, Sam Robinson, Melissa Santos, Kristal Dixon, Zachery Eanes, Alex Golden and Asher Price contributed to this story.