Oh I don't know, looks like a nice walk up if it hasn't rained(!)
Not as big a detour as I thought but I thought the bridleway was closed too. I see the sign doesn't say which side of the flyover and the map isn't clear. Still a stiff climb if you were expecting a tunnel!
There is a bridleway either side of the A14 that joins up with the Midshires Way.. As you say, the poster/map isn't too accurate by the looks of it!