IMO the media may have misreported any highway being as north as Highway 7, as Fontana sprung this on everyone by the sounds of it. With few details provided they assumed current Highway 7 would be the same route as a freeway.
I made a quick paint version from google maps of a functioning ring road, that stays away from most developed areas. Have Highway 7 to branch off at 7 & 119 head southwest towards London. North of Lake Fanshawe go along Medway Road, meet up with Clarke/VMP, swing up to 8 Mile Rd. Go along 8 mile until Wonderland then swing back to Medway, until Highway 22, follow that to near 402. Proposed West End Freeway along Woodhull/Westdel Bourne. Similar to the 1966 Freeway Plan that was reject, now just several km north moreso.
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Although this doesn't do much. Current traffic problems are more
IN London. Much bigger fish to fry. Rail lines constraining north-south routes (Wharncliffe, Adelaide, Richmond) and the Thames creating east-west missing links (Riverside-Dundas-King, Sarnia-Huron, Gainsborough-Windemere-Killaly). Either a Sarnia-Huron or a Gainsborough-Windemere-Killaly connection would provide more real relief for London commuters, but are a can of worms most politicians puss out on.