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1 DECISIONSUPPORTINGSYSTEMS
Thedevelopmentofinformationandcommunication
technologies (IT and ICT) creates increasing
opportunities for acquiring, processing and sharing
information. The need for improvement and
extensionof navigationalequipmentandsystemson
shipsandinland‐based centersresultsfromthefact
that the safe navigation and vessel t
raffic
management require access to relevant information
anditsproperuse.Navigationalsystemsanddevices
are systematically supplemented with new
functionalities. On the one hand, the
operator/navigator acquires additional information,
on the other hand, excess information makes the
selection of relevant information more difficult and
consequently hampers making the correct decision.
For thi
s reason, greatemphasis is placed on human
centereddesignofsuchsystems.
Currently used navigational systems and devices
increase the scope of support in decision‐making
processesbyusingpredictionalgorithmsorstatistical
tools.Moreandmoreattentionispaidtonavigation
decision support systems that additionally allow to
generatesolutionstoanavigationsituation,including
collision situations. Thesesolutions are presented to
the navigator or operator. This is part
icularly
important in complex decision‐making situations in
difficult conditions: storm, restricted visibility, high
traffic. NAVDEC is an example of the navigational
decision support system on seagoing ship
(Pietrzykowski & Borkowski & Wołejsza, 2012). The
systemenables,int
eralia,analysisandassessmentof
thenavigationsituation,andgenerationofavoidance
manoeuvres in collision situations. Proposed
solutionsshouldbe effective, legal andrational.The
third requirement relates to navigators/operatorsʹ
preferences resulting from their knowledge and
experience(Pietrzykowski& Magaj&Maka,2014).
This is very import
ant because the collision
regulations leave a certain margin for interpretation
andaction.Thecreationofarationalsystemrequires
the application of complex models and computing
algorithms. The automatic generation of solutions is
particularly important in encounter situations in
dense traffic areas. These areas, mainly port
a
pproaches and frequently used shipping routes,
are often restricted (limitation of one of three
dimensions). There is a whole range of constraints
Navigators’ Behavior in Traffic Separation Schemes
Z.Pietrzykowski,P.Wołejsza&J.Magaj
M
aritimeUniversityofSzczecin,Poland
ABSTRACT: One of the areas of decision support in the navigational ship conduct process is a Traffic
SeparationScheme. TSSsareestablishedinareaswithhightrafficdensity, often near the shore and in port
approaches.Themainpurposeoftheseschemesistoimprovemaritimesafetybychannelingvesselt
rafficinto
streams.TrafficregulationsaswellasshipsbehaviorinrealconditionsinchosenTSSshavebeenanalyzedin
ordertodevelopdecisionsupportalgorithms.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 9
Number 1
March 2015
DOI:10.12716/1001.09.01.15
122
which restrict ship maneuvers: shipʹs dimensions,
shipmaneuverability,shapeanddepthofthewater
area, obstacles and navigational dangers, legal
regulations , other sea‐going vessels, drilling
platforms,windfarmsandother.
The use of decision support systems in areas
whereTSSsareestablishedrequiresthatsuchsystems
should
take into consideration general and TSS‐
specificregulationsaswellasnavigatorsʹexpertise:
experience and knowledge needed for analysis and
assessmentofthesituationandforthedetermination
of safe maneuvers, i.e. calculation of a safe ship
trajectory. One of the possibilities is presented in
(Szlapczynski,2012).
2 TRAFFICSEPARATION
SCHEMES
TSScanbedescribedas atraffic‐managementroute‐
system ruled by the IMO where the traffic lanes
indicate the general direction of the traffic flow.
IMOʹsresponsibilityforshipsʹ routing is set forth in
SOLASChapterV,whichrecognizestheOrganization
as the only international body for establishing
such
systems.Shipsʹroutingsystemscontributetosafetyof
lifeatsea,safetyandefficiencyofnavigationand/or
protectionofthemarineenvironment.Rule10ofthe
COLREGs(COLREGs,1972)prescribestheconductof
vessels when navigating through traffic separation
schemes adopted by the IMO. However, this in no
way
relieves vessels from compliance with other
COLREGsrules.Itshouldbenotedthattherearealso
TSSnotgovernedbytheIMO.
ThetrafficlanesinTSSaredemarcatedbyvirtual
boundaries.Thismeansthatboundaryviolationdoes
not imply directly a risk of grounding or collision
with the shore. In
many cases vessels simply sail
acrossaTSS.Insuchsituations,theshipshallcross
onaheadingʹasnearlyaspracticableatrightangles
to the general direction of traffic flowʹ. The
regulationsalsoallowashiptojoinorleaveatraffic
laneattheterminationof
thelane, butwhenjoining
or leaving from either side shipsʹshall do so at as
smallanangletothegeneraldirectionoftrafficflow
aspracticableʹ.
Such wording leavesroom for interpretation
(tolerance range) by decision‐makers. Both the
navigator and the decision support system should
take such
interpretation margin into account in the
analysis and assessment of the situation and in
determiningamaneuvertosolveacollisionsituation.
In this connection, the authors have analyzed
vessel traffic in selected regions of the Baltic Sea
where TSSs are established: TSS Adlergrund, TSS
Bornholmsgat,TSSNorthofRügen
andTSSSłupska
Bank(Figures1‐4).TheanalysismakesuseofAIS
data registered during one day in June 2011.
Individualshipencountersituationsandvesseltraffic
flowshavebeenanalyzed.
The analysis is aimed to develop and test the
methodologytobeusedinfurtherresearch.
Figure1.TSSNorthofRügen
Figure2.TSSAdlergrund
Figure3.TSSBornholmsgat
Figure4.TSSSłupskaBank