After the war, when Birkenhead had suffered quite a bit of bomb damage, allied to the fact that at that time there was a lot of poor quality housing, the Corporation commissioned a grand plan for the re-development of the town.
I'm fortunate to have a mint copy of this book, still in its slip case and with the complete map which measures about three feet square and lives in a pocket at the end of the book. The book itself is large, measuring about 12" x 10".
Here's a taste of the book.

Very interesting regarding ferry services
Them ferry service numbers are staggering, considering the other options of the railway and the Mersey tunnel
Regarding 'G'. Why was the ferry still used for motor vehicles?
Was it cheaper than a passage through the tunnel?

As it says , 40% was horse drawn traffic which was not allowed in the tunnel; also I suspect there would have been quite a few drivers who would have felt nervous in a long underwater tunnel. According to the schedule at 'G', only 15% was private cars.
As far as cost goes, I can't find out what the toll for a car was when the tunnel opened, all I can find out is that the goods ferry toll in 1905 for a four seater car was 1 shilling: using the relative RPI, that equals nearly five pounds today. Larger cars were charged between 1/6d and 3 shillings. The tunnel toll for a car in 1971 was 10p.
The luggage boats finished in 1941.

If anyone's interested, there's a copy of the 1947 Plan in the archives, or at least there was when the archives were in the Town Hall.

I got the 40% horse drawn traffic
My question was "Why was the ferry still used for motor vehicles?"
If you take into account the scared commuters not wanting to travel through the tunnel, (I suppose it was like flying a plane when the tunnel opened) it is still a staggering number crossing the Mersey on a motor vehicle via a boat, when in fact the tunnel had already been opened for over 10 years
Don't you think it is a bit high?

If you allow that only 15% of the total was commuters, travelling five days a week, that's only 35 cars a day, which is a tiny number compared with those using the tunnel. By the same token, many commuters chose to continue to use the ferries even after the Mersey Railway was electrified and therefore made more pleasant. I guess people just thought it made a pleasant start to the day.

I must be missing something here Chris
30% is motor traffic between liverpool and Birkenhead docks
16% Petrol transport from Ellesmere Port and North Country
That is what is confusing me, the above figures
The remanding 15% is what you are referring to, yes?

Yes, I'm considering only what might be termed commuter traffic.