Finally we seem to have a answer to the mystery over Old Broad street and the confusing signage.
After many emails to the COL(corporation of London ) the LCDC can hopefully clear up where we can drop off in Old Broad Street.
This is hopefully the last email on this matter, reply from Jon Wallace who is the Highways and Traffic Manager for the Square mile
There are two sets of No Motor Vehicles signs on Old Broad Street. The first one that you would encounter at the southern end of the street has an “Except for Buses and Loading” supplementary sign. The second No Motor Vehicles sign has an “Except for Buses and Loading by Lorry” supplementary sign. The intention is that it is only the area controlled by the “Except for Buses and Loading by Lorry” sign will be enforced for taxis. This means that you will be able to travel as far north as Broad Street Avenue.
In the event that your passenger has limited mobility or heavy baggage, closer access can be achieved via the Primrose Street station access.
I hope this clarifies the position
Hope that’s finally cleared up this very confusing matter.
So we can get into New Broad Street, Dashwood House and drop off.
But do NOT go past the second sign which is shown above as a PCN will be issued!!