How many children ride school buses daily?

There's no single, readily available answer to how many children ride school buses daily worldwide. The number varies drastically depending on the country, state/province, and even individual school district. Data collection on this scale isn't consistently done globally.

To get a number, you'd need to compile data from countless sources across the world, which is a massive undertaking. You might find statistics for specific regions (e.g., the number of children who ride school buses in California), but a global figure is unlikely to exist in a readily accessible, reliable form.