To reduce the risk of collision, ships moving through the Strait follow a Traffic Separation Scheme (TSS): inbound ships use one lane, outbound ships another, each lane being two miles wide.
In April 1959 when Iran attempted to alter the legal status of the strait by expanding its territorial sea to 12-nautical-mile (22 km) and declaring that it would recognize only transit by Innocent passage through the newly expanded area [REF].