We have obtained an official entry for Westfield Common (CL 121) from the statutory register required by the Commons Registration Act.
A map excerpt is shown below showing the clear boundaries of the common (click on the map for a larger image):

Some observations:
- As you can see not all the paths that are in use have been officially recorded.
- Interesting long narrow strips of common land stretching up Moor Lane and on the western side of New Lane.
- Some of the streets – south Westfield Common, east Highlands Lane, Bonners Close and Willow Bank are common land.
The official registry entry is attached here Commons Register – CL121
All rights acknowledged.
Related posts:
- Common Land – Statutory Protection Westfield Common is registered as CL121 in the Common Land...
- Westfield Common – Registration FOI Request update FYI – copy of response of FOI request to establish...
- FOI Request – Responses to Consultation on Proposed Exchange of Common Land at Westfield Common A Freedom of Information request to Woking Borough Council. Bill...
- 3rd Party Land Ownership – Moor Lane & Wesfield Common Just some initial high-level comments on the 3rd party land...
- Common Land Exchange – Letter to the Planning Inspectorate A letter of objection was sent by WCRA to the...

This is very much in liine with the Surrey Structure Plan for Westfield and Mayford:
http://www.woking.gov.uk/planning/policy/localplan/kingfield/kingfieldpdf.pdf
http://www.woking.gov.uk/planning/policy/localplan/mayfordpdf/mayfordpdf.pdf
As you indicate Moor Lane beyond Rosebank Cottages is designated Urban Open Space
A merged copy of the policy maps from the two pdfs posted by Colin can be found here:
http://westfieldcommon.wordpress.com/2009/05/20/know-your-area/