The argument that the "oppressed" "motorist" is the one being forced to cough up in order to the Government's largesse is simple to default. The bald fact is that car drivers don't even pay their own way, let alone fund a surplus that can be hosed at outreach workers for gay whales.
Oh dear, oh dear, oh dear - Poor old Blognor has got all caught up in the romance of steam - the simple facts are that "The net tax revenue per lane-mile for the Motorway and Trunk Road network has the range £(275-360) thousand per year. In contrast the 20,000 miles of rail track is being subsidised to perhaps £5 billion per year or at the rate of £250 thousand per track-mile... Very much against public and political sentiment roads managed to avoid congestion would offer 3 to 4 times the capacity to move freight and people at one quarter the cost of rail while using 20% to 25% less energy and reducing casualty costs suffered by rail passengers by a factor of 2.
The problem with the proposition is that (a) it is so very much against expectation (b) the numbers are so overwhelming as to inspire disbelief rather than belief (c) few people have ever seen a motor road managed to avoid congestion - the UK road network is (with the exception of motorways and some modern single carriageways) a collection of access roads never designed for motor traffic (d) rail is so romantic.
And to say nothing about push bike riders who pay nothing towards Her Majesty's Highways....