This is the sign by the north west side traffic lights at the junction of Acton Lane and Chiswick High Road and there is an identical sign on Acton Lane under the rail bridge as the road rises from Acton Green Common to Chiswick Park tube station. Presumably there is also a third in Bollo Lane. I rang the number (National Grid) and they were unable to confirm the road would be closed in both directions from the High Road to Bollo Lane or if, effectively, that major Acton Lane through route would be closed for 10 days as the details had yet to appear on their system. Do you have a link to the info, Pete?