Thursday's budget committee took evidence from TfL witnesses and Kulveer Ranger - the mayor's director of transport policy - on the contentious subject of fare rises.
Setting the fares is a power exercised by the mayor, with reference to the TfL budget and professional advice. TfL forecasts its requirements annually in the October business plan and these are firmed up in the March budget. A number of factors are making predictions unusually challenging this year.
Recent months have seen London Underground ridership - and therefore revenue - falling. The number of Underground passengers correlates closely to the number of people commuting to jobs in the capital, so the recession is having an effect, although the impact is less damaging in London than in other parts of the country.
However bus ridership remains unchanged, partly because a different demographic group uses buses and partly because inability to afford Tube fares pushes passengers onto buses as an alternative.
And the good news is that the number of tourists is up, responding to the favourable exchange rate. This particularly affects passenger numbers in zone one.
So given the turbulent position, TfL were reluctant to hazard a long term forecast at this time.
Obviously TfL is required to balance its budget, but key objectives in the coming year include:
Protecting the capital programme, most importantly Crossrail. Lower inflation rates in the construction sector may actually lead to savings against this budget heading.
Progressing with the introduction of Oyster pay as you go on main line rail services.
Continuing migration from cash payment to Oysters - interestingly, only 1.4% of bus revenue is now generated by 'on bus' ticket sales. And the figure is probably lower for bendies.
The committee briefly considered an idea for TfL 'loyalty cards' floated by Lib Dem Caroline Pidgeon. The idea would be to reward passengers for travelling during off peak periods. It is an intriguing suggestion which the committee may well return to in detail on another occasion.