A new Mersey tunnel exit could eventually be built to stop traffic tailing back in Liverpool city centre after the demolition of the Churchill flyovers.
But the Liverpool City Region report detailing the idea warns that the new exit would have to be a long term goal because of the astronomical cost of a new opening.
An operation and maintenance strategy for the tunnels, which was discussed by the combined authority's transport committee this week, says the closure of the Churchill Flyovers has caused congestion close to the Queensway Tunnel entrance - and long term solutions may include a new tunnel exit.
The flyovers are being dismantled after being found to be in a decrepit condition.
The report says: "The closure of Churchill Way Flyovers has caused significant congestion at the Old Haymarket roundabout and surrounding areas.
"In view of their impending demolition, there is an opportunity to remodel the approach routes and junctions with Old Haymarket and Scotland Road, which would significantly improve traffic flow and journey times, whilst also improving air quality in the city centre.
"Consideration may need to be given to the feasibility (layout and cost) of a new exit point, to ease traffic congestion in the city centre and prevent standing traffic in Queensway Tunnel.
"However, the cost of a new tunnel branch is likely to be in the region of £250 to £350m, and it is clear that in the short term this would be cost prohibitive, although remains a longer term consideration."
There is no exact time frame given for how long a new exit would take to construct.
Aside from the current entrances and exits to the two Mersey tunnels, there is also a closed route in Birkenhead.
The ECHO has previously reported on the Rendel Street branch of the Queensway tunnel.
Pictures of the inside the tunnel which connects the entrance to the main part of the tunnel were released by the ECHO two years ago.
It has been shut for decades because its location on a blind bend was deemed to dangerous for traffic to use safely.
