Integration with the comms?
Hasn't there been some fluttering in the dovecotes recently over the communications infrastructure?
Things like selecting a mobile phone provider with no coverage inside the Underground?
If your communications infrastructure (possibly one major part of C&C) is a moving target then it may be very difficult to integrate you software.
London is not like most other UK cities because of the Underground network. I have no idea if systems from other major cities such as New York reflect the way that the UK does things. No doubt we shall learn more in time.
Back in the days when I worked on bids the aim of the game was to expend minimal effort on winning the bid, keep things nice and loose in the contract, then do the real design work if you won. Make any under bid back through the inevitable change control when the customer realised that what the specification said wasn't what was really needed. I don't suppose that things have changed that much. Note that this was often agreeable to both sides, especially if the customer had a "use it or lose it" budget allocation and was in the last financial quarter.
I have commented before on the impossibility of delivering if politically motivated changes arrive at a faster rate than the ability to deliver to the previous specification.