Cafodd y setliad rheilffyrdd presennol ei ddylunio cyn dyfodiad datganoli.  Er bod rhai ymdrechion wedi’u gwneud i’w esblygu, mae’r setliad presennol yn dal yn adlewyrchu'r cyfnod pan gafodd ei lunio.  20 mlynedd ers datganoli, yr Ysgrifennydd Gwladol dros Drafnidiaeth yn San Steffan sy’n dal â rheolaeth dros y rheilffyrdd yng Nghymru yn y pen draw.  Mae’r setliad datganoli diffygiol hwn yn sail i lawer o’r problemau yng nghyswllt ein rheilffyrdd.
The current railway settlement was designed before the advent of devolution.  Although some efforts have been made to evolve it, the current settlement is still a reflection of the times in which it was created.  20 years on from devolution, the Secretary of State for Transport in Westminster retains ultimate control of the railway in Wales.  This imperfect devolution settlement is the root of many of the problems with our railway.