In the vicinity of the existing Metro bridge, the proposed scheme would provide a new toll plaza for southbound traffic near to the East Howdon bypass. Toll booths would be provided along with offices, car parking and garage facilities for tunnel staff and vehicles. A vehicle inspection area would be provided and any vehicle prohibited from entering the tunnel would be directed to the East Howdon Bypass via a newly constructed access road.

The scheme would then extend south through an open cutting for a distance of approximately 650 metres as far as the tunnel entrance. At this point, the road would enter a cut and cover tunnel section, approximately 320 metres long which would extend as far as the river bank, where (Point A) it would connect with the immersed tube positioned within the river bed.

The existing toll plaza at the northern end of the tunnel would be re-configured to accommodate northbound traffic only.