From Merseytravel site -
Lighting upgrade at Kingsway Tunnel
On your journey through the Kingsway (Wallasey) tunnel you may notice some changes and activity over the coming weeks and months. This is because we are replacing the lighting in a £8million scheme, scheduled to be completed in summer 2017.
The majority of work is taking place during scheduled maintenance closures, mainly during night time when our traffic volume is at its lowest, causing minimal disruption to your journey. Tunnel lighting will also be maintained through the works and the end result will see an improvement in lighting at road level. 75 miles of cable – the equivalent distance of Liverpool to Leeds – will be installed as part of the work, which will also see existing lighting replaced with more efficient LED units, reducing electrical consumption, leading to lower running costs and fewer CO2 emissions.
The rewiring is part of a 10 year investment programme for the tunnels to ensure that they are kept safe and efficient and in top condition for the 25 million vehicles that pass through them each year. The work will be funded through money set aside from the Mersey Tunnel Tolls.