When I was young, Wolverhampton had two adjacent stations near the town centre. The former L.M.S. station was nearest to and built on the same level as the town centre. Since the town centre was partly on a hill, the lines approaching the L.M.S. station were raised on embankments or viaducts. The former G.W.R. station was parallel to the L.M.S. station but at a lower level. The Great Western line from the south reached the station through two single line tunnels whilst that to the north was more-or-less at ground level until Stafford Road Works, after which it crossed a valley on a viaduct to reach Oxley and the route to Shrewsbury.
With admirable logic, the two stations were called 'High Level' and 'Low Level'. To cater for passengers interchanging between stations, a combination of steps, a subway and a ramp allowed pedestrians to walk between the stations. The main passages remain (as a listed structure, I think) although the original purpose was lost with the closure of the Low Level Station. The passages still provide a useful short-cut to those on foot between the Wednesfield Road and the present station frontage.
The Stour Valley Line was an important route linking Wolverhampton High Level with Birmingham New Street via the exotic-sounding Dudley Port. This was the route most passenger trains took, although it was possible to reach Birmingham through a connection to the 'Old Road' via Bescot, actually part of the former Grand Junction Railway opened in 1837 long before the Stour Valley and only the third main line railway to be planned in England (after the Liverpool and Manchester and London and Birmingham). I got to know the Stour Valley well, particularly when I started visiting signal boxes along that route (see 'Visiting Signalboxes'). But the 'Old Road', with its major marshalling yards and motive power depot at Bescot, retained its fascination, as I described in the article '9:17 a.m. to Birmingham'.
More on Wolverhampton High Level.
This is an informal, incomplete listing of books to hand with at least some relevance to West Midland Railways.
[ 1] 'Wolverhampton Railway Album Volume 1' by Simon Dewey & Ned Williams (Uralia Press) ISBN 0 9500533 2 5.
[ 2] 'Wolverhampton Railway Album Volume 2' by Simon Dewey & Ned Williams (Uralia Press) ISBN 0 9500533 3 3.
[ 3] 'Rail Centres: Wolverhampton' by Paul Collins (originally published in 1990 by Ian Allen, reprinted by Booklaw Publications in 2008) ISBN 1-901945-23-5.
[ 4] 'Staffordshire Railways' by Mike Hitches (Allan Sutton Publishing) ISBN 0-7509-0869-6.
[ 5] 'Lost Railways of Birmingham & The West Midlands' by Terry Moors (Countryside Books) ISBN 978 1 84674 109 8.
[ 6] 'D. J. Norton's pictorial survey of Railways in the West Midlands Part 1' by R. J. Essery (Wild Swan Publications) ISBN 978 1 902184 50 7.
[ 7] 'Pre-grouping in the West Midlands' by P. B. Whitehouse (Oxford Publishing Co.) ISBN 0-86093-328-8
[ 8] 'Black Country Railways' by Ned Williams (Alan Sutton Publishing) ISBN 0-7509-0934-X.
[ 9] 'Birminghham Railways in Old Photographs' by Mike Hitches (Alan Sutton Publishing) ISBN 0-7509-0027-X.
 'Birmingham Railway Scene' by C. C. Dorman (Town & Country Press).
 'The Railways of Dudley' by Ned Williams (Uralia Press) ISBN 1 898 528 02 0.
 'Branch Line Byways - The West Midlands' by G. F. Bannister (Atlantic Transport Publishers) ISBN 0 906899 23 0.
 'Tipton - A Third Selection' by Keith Hodgkins & John Brimble (Sutton Publishing) ISBN 978-0-7509-2832-8.
 'New Street Remembered' by Donald J. Smith (Barbryn Press Limited) ISBN 0 906160 05 7.
 'Birmingham New Street - Background and Beginnings' by Richard Foster (Wild Swan Publications) ISBN 0 906867 78 9.
 'Birmingham New Street - Expansion & Improvement' by Richard Foster (Wild Swan Publications) ISBN 0 906867 79 7.
 'Monument Lane Loco Shed' by Tony Higgs (Brewin Books) ISBN: 978-1-85858-435-5.
 'Wolverhampton to Stafford' by Vic Mitchell (Middleton press) ISBN: 978 1 908174 79 6.
 'West Midlands' by J. B. Bucknall (Ian Allen Publishing) ISBN 0 7110 2250 X.
[Book References 18,19 added 15-Sep-2015]