Bidirectional traffic
In transportation infrastructure, a bidirectional traffic system divides travelers into two streams of traffic that flow in opposite directions.Bidirectional traffic is observed in a wide variety of a...
Airway (aviation)
An airway is a legally defined corridor that connects one specified location to another at a specified altitude, along which an aircraft that meets the requirements of the airway may be flown. Airways...
Double track
A double-track railway usually involves running one track in each direction, compared to a single-track railway where trains in both directions share the same track.
In the earliest days of railw...
Double tracking
Double tracking or vocal doubling is an audio recording technique in which a performer sings or plays along with their own prerecorded performance, usually to produce a stronger or "bigger" sound than...
Single-line working
On a double track railway, single-line working refers to the practice of using one track out of two, usually when one of the tracks is out of use for maintenance or because of damage or some obstructi...
Right- and left-hand traffic
The terms right-hand traffic and left-hand traffic refer to regulations requiring all bidirectional traffic, unless otherwise directed, to keep either to the right or the left side of the road, respe...