Traffic separation schemes (TSS) are regulated by the IMO to control ship traffic in busy waterways. A TSS consists of lanes indicating the direction of travel, separation zones between lanes, and inshore traffic zones. Ships must sail in the direction of the lanes and avoid the separation zones as much as possible. The objectives of a TSS are to reduce head-on encounters and manage crossing situations while providing safe routes for ships.

1. RECOGNIZES TRAFFIC LANES AND
SEPARATION ZONE

2. TRAFFIC SEPARATION SCHEME
 is a traffic-management route-system ruled by the International
Maritime Organization or IMO. The traffic-lanes (or clearways)
indicate the general direction of the ships in that zone; ships
navigating within a TSS all sail in the same direction or they cross
the lane in an angle as close to 90 degrees as possible.

3.  TSSs are used to regulate the traffic at busy, confined
waterways or around capes. Within a TSS you normally see
at least one traffic-lane in each main-direction, turning-
points, deep-water lanes and separation zones between
the main traffic lanes. In most TSS schemes you will find
Inshore Traffic Zones between the traffic-lanes and the
coast. The inshore traffic zone is unregulated and shouldn't
be used for ongoing traffic. It is meant for local traffic,
fishing and small craft.

4.  A ship navigating in a traffic-lane should sail in the
general direction of that lane. The body of water
between two opposite lanes is to be avoided by vessels
travelling within the TSS as far as possible except in
certain circumstances such as emergencies or for
fishing activities.

5. Example of TSS on a chart

6. Objective of a TSS
Objectives of IMO Routine Schemes:
 1.Help reduce and manage head on situations for the streams of opposing traffic
 2. Help manage crossing situation arising while entering or coming out of port
 3. In areas of offshore activities, directives regarding safe distance from the
installations
 4. Providing routes for deep draught vessels
 5. Avoiding presence of routine traffic from some areas as desired by administration
 6. Better management of inshore traffic zone, fishing zones and areas dangerous to
navigation due to presence of isolated dangers and shoal patches in a high density
traffic area.

7. Crossing a TSS
 If a ship wants to cross a traffic-lane it should do so at a right
angle to avoid endangering ship traffic using the traffic-lanes
(although traffic in the lane does not automatically have the
right-of-way). To minimize the amount of time a crossing ship
spend crossing the traffic-lanes, there should be a right angle
between the lane direction and the keel direction - even if
currents might shift the actual direction of the ship's movement
to some angle other than 90 degrees.

8. Locations of Traffic Separation Schemes
 TSSs are used in locations where there is a lot of traffic (busy
shipping areas) where not regulating the traffic would lead to
more accidents. In Europe, many TSS areas are found around
the Southern part of the North sea including the English
channel. Other TSS are in place off Land end and around
Ouessant (Ushant).