Mr Coleman spent £656 in just one day
An £8,231 expenses claim for taxi rides by a London Assembly member has led to calls for a tightening of the rules.
Tory Brian Coleman amassed the costs between April 2007 and March this year, despite having free a Travelcard.
No rules were broken but he was criticised last year for running up a £10,000 cab bill.
Mr Coleman, who has been appointed by the mayor as chairman of the London Fire and Emergency Planning Authority, has refused to comment.
His expense claim included a taxi bill of £656 in just one day last December, during which kept a cab waiting two-and-a-half hours.
Checks and balances
Mr Coleman's taxi bill was almost as large as all of the other 24 members of the assembly put together.
The average taxi bill for an London Assembly member was about £685.
Labour London Assembly member Navin Shah called for the expenses system to be made stricter.
"Any system which hasn't got checks and balances is open to abuse," he said.
In 2007, the then London Mayor Ken Livingstone said Mr Coleman's £10,000 bill was "an example of extravagance for no purpose".