The National Transport Plan has been informed by Professor Preston’s report on Approaches to Strategic Transport Planning commissioned via the Public Policy Institute Wales.
Seiliwyd y Cynllun Trafnidiaeth Cenedlaethol ar adroddiad yr Athro Preston ar Sut i Gynllunio Trafnidiaeth yn Strategol, a gomisiynwyd gan Sefydliad Polisi Cyhoeddus Cymru.