Other way around. In 2MT, both mains are signaled bi-directionally and capable of handling traffic in either direction at normal track speed. In DT, other than at interlocking points, each main is typically signaled for movement in one direction only. In most locations with DT operation, Track 1 is for westbounds, Track 2 for eastbounds. Where movement is considered northbound/southbound by timetable, it varies by railroad or subdivision which of the two tracks is numbered 1 and which is numbered 2. When movement is made against the current in DT, permit may, or may not, be required depending on the particular operating rules in place.