core lane

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Canada In a multi-lane controlled-access highway or expressway system, a lane close to the median and physically separated from the outer lanes, which has fewer entrances and exits than the outer lanes and which is intended for vehicles traveling longer distances, so that these vehicles may proceed in a relatively uninterrupted manner and often at greater speed. (Contrasted with a collector lane).