Is highway capitalized when used in a sentence with number?

Generally, "highway" is not capitalized when used with a number.

For example, you would write:

* "I took Highway 101 to get to the beach."

Exceptions:

* Official names: If the highway has a specific, official name, then you would capitalize it, like "Interstate 5" or "U.S. Route 66".

* Proper nouns: If "highway" is part of a proper noun, like "Highway 66 Scenic Byway," then you would capitalize it.

In most cases, though, "highway" is lowercase when used with a number.