( also interstate highway ) n
any of the national US roads that cross state borders. They have four lanes (= sections for single lines of traffic) and run for long distances. They are marked with red and blue signs, an ‘I’ and the road number. Interstates going east to west have even numbers and those going north to south have odd numbers. I-80 goes from New York to California , and I-95 goes from Maine to Florida . They are usually referred to in this way:
They’re building a new motel on I-10.