Sorry - we haven't much to contribute because we're not familiar with the details of the 1992 judicial review.
I'm not aware of any Admissions Code
stating that grammar schools in a 'one tier system' cannot have catchments, so I'm guessing there may have been something very specific in the judgement.
The latest Code is a simplified, slimmed down document, and the only references I can find to catchment areas are:
1.14 Catchment areas must be designed so that they are reasonable and clearly defined. Catchment areas do not prevent parents who live outside the catchment of a particular school from expressing a preference for the school.
Catchment Area [definition]
A geographical area, from which children may be afforded priority for admission to a particular school. A catchment area is part of a school’s admission arrangements and must therefore be consulted upon, determined and published in the same way as other admission arrangements.
[footnote] R v Greenwich London Borough Council, ex parte John Ball Primary School (1989) 88 LGR 589  Fam Law 469 held that pupils should not be discriminated against in relation to admission to the school simply because they reside outside the local authority area in which the school is situated. Section 86(8) of the SSFA 1998 places an equal duty on local authorities to comply with parental preference in respect of parents living within and outside their boundary.
When referring to the Greenwich judgement, it would be worth noting the Rotherham judgement too. My somewhat simplistic explanation can be found here:http://www.elevenplusexams.co.uk/appeal ... -school#c9
The 'Home to School Travel and Transport Guidance' document you mention (Transport DFES-00373-2007
) is hedged about with reservations and is no more than 'guidance'.
You quote it very fairly: "What may be considered a reasonable journey time will also depend on a number of factors, including the age and any individual needs of the child. For example, best practice suggests that the maximum length of journey for a child of primary school age might be considered to be 45 minutes; whilst a child of secondary school age might be expected to travel up to 75 minutes each way.
" [My highlighting]