The Emerald Express (EmX) is a bus rapid transit (BRT) system in the Eugene-Springfield metropolitan area in Oregon, United States. It is provided by the Lane Transit District (LTD) which is the public transit authority in Lane County, Oregon. LTD chose bus rapid transit after a review process in which several transportation options, including light rail, were considered. It was decided that the BRT option was the best fit for Eugene-Springfield's size and current transportation needs.