It says "PEAS" is the tag of a London graffiti artist and his tag can been seen in many other locations, particularly on bridges. The additional text changing the graffiti to read "GIVE PEAS A CHANCE" is thought to refer to his continual arrests.
The north facing side of the bridge also has some graffiti, saying just "PEAS06".
"The common misinterpretation of the inscription makes the bridge an interesting landmark to users of the M25," says the report.