Well sure i like trains, but you have to be realistic.
The nearest major motorway interchange (which in British terms is a pretty important one) currently moves about 120,000 vehicles every day, being economic that's proberbly over 200,000 people (and many more tons of goods). The parallel rail routes take about 25,000 people a day, some coal, some rubbish to landfill, a bit of aggregate and a few car trains each day. Hmm. Given that in this country the 'subsidies' for the strategic road (motorway) network and rail are about the same (£2.4 billion last time i bothered to look), than you quickly see what the problem is.
An addendum is that the railway lines in this area actually make money... but the principle holds that even for a 5% reduction in motorway traffic your looking at doubling the capacity of the railways at colossal expense and ongoing expense in most cases.
So reducing congestion... i dunno whether that argument stands up. Replacing short haul flight, regeneration and accessibility are much more valid arguments imho.