. ▁ ▁Organisation ▁For ▁historical ▁and ▁ge ographical ▁reasons ▁the ▁railway ▁network ▁of ▁the ▁United ▁Kingdom ▁is ▁split ▁into ▁two ▁independent ▁systems : ▁one ▁in ▁Great ▁Britain ▁( including ▁the ▁Is le ▁of ▁W ight ), ▁and ▁one ▁in ▁Northern ▁Ireland , ▁which ▁is ▁closely ▁linked ▁to ▁the ▁railway ▁system ▁of ▁the ▁Republic ▁of ▁Ireland . ▁ ▁Great ▁Britain ▁ ▁In ▁Great ▁Britain , ▁passenger ▁train ▁services ▁are ▁operated ▁by ▁a ▁number ▁of ▁companies , ▁referred ▁to ▁as ▁Train ▁Oper ating ▁Comp an ies ▁or ▁TO C s , ▁normally ▁on ▁the ▁basis ▁of ▁regional ▁franch ises ▁awarded ▁by ▁the ▁Department ▁for ▁Transport ▁Rail ▁Group . ▁Until ▁ 2 0 0 5 ▁this ▁role ▁was ▁performed ▁by ▁the ▁Str ateg ic ▁Rail ▁Author ity . ▁The ▁infrastr ucture ▁of ▁the ▁rail ways ▁in ▁England , ▁Scotland , ▁and ▁Wales   – ▁including ▁tracks ▁and ▁sign alling   – ▁is ▁owned ▁and ▁operated ▁not ▁by ▁the ▁train ▁companies ▁but ▁by ▁Network ▁Rail , ▁which ▁took ▁over ▁responsibility ▁from ▁Rail track ▁in ▁ 2 0 0 2 . ▁Most ▁passenger ▁trains ▁are ▁owned ▁by ▁a ▁small ▁number ▁of ▁rolling ▁stock ▁companies ▁and ▁are ▁le ased ▁to ▁the ▁individual ▁TO C s . ▁However , ▁a ▁hand ful ▁of ▁TO C s ▁own ▁and ▁maintain ▁some ▁of ▁their ▁own ▁rolling ▁stock . ▁Train ▁operating ▁companies ▁also ▁operate ▁most ▁of ▁the ▁network ' s ▁stations , ▁in ▁their ▁role ▁as ▁station ▁facility ▁own ers ▁( S FO ), ▁in ▁which ▁they ▁le ase ▁the ▁buildings ▁and ▁associated