The survey also looked at some of the strange objects left behind in cabs around the world, they include:
- A wig and a bird in a cage left behind in a US cab
- A prosthetic leg and an ex-boyfriend left in an Australian taxi
- A trombone in Finland
- Dentures in Germany
More top news
The plaque at number 16 Cowley Street in Westminster marks the brown brick Georgian townhouse where Sir John lived for 31 years.
A man reportedly armed with several knives has been arrested in Whitehall on suspicion of planning a terror attack, police have said.
Metropolitan Police officer, Tom Harrison, has been crawling the course since the race began on Sunday morning.