There is a great tool available online for school bus driver to determine there 100 air mile radius.
Just remember when you enter the 100 air miles in the box for miles to enter 115.
The map above is 100 air miles for our 3 different school bus yards here in Sonoma County.
Air Miles Vs Statute Miles
Air miles are a different measurement of a mile than what is used for statute miles on a roadmap. An air mile is longer than a statute mile. There are 6,076 feet in an air mile and 5,280 feet in a statute mile. One-hundred air miles is equal to 115.08 statute miles. Therefore, a 100 air-mile radius from your work reporting location can be figured as 115.08 statute or “roadmap,” miles (185.2 km) from your work reporting location.