Essex County Council County Road Map
Four one inch maps covering the county, sold by Stanfords but using OS maps.
The classifications are of First & Second Classes of "County Roads" - ones they were responsible for? Manual additions to the map are the roads that are "Sections to be Improved" (blue lines) and "Revision of route" (dashed blue lines).
Scale correct at 5 miles = 127mm, or 1.0 mile/inch, ie 1:63,360.
The A127 Southend Arterial is present (opened 1925) and the Stanford-le-Hope bypass (c.1930), but the Chelmsford bypass is only shown as planned (1931) and the railway line to Allhallows is not present (1932); from these the estimated date is 1930.
More details on ECC's maps are on the Publisher's page.