Denzel Washington simply said, no thanks, after waiting 3 months for 20^th Century Fox to set a budget and a start date for the now ill-fated Unstoppable train movie to be directed by Tony Scott. 

Scott and Washington had planned since April to work together again on Unstoppable.  This time Washington playing a veteran engineer who jumps into a locomotive with a young conductor (Star Trek‘s Chris Pine) to halt an unmanned runaway train filled with a toxic chemical.

The powers that be asked Scott to cut his salary from $9 million to $6 million and wanted Washington to trim $4 million off his $20 million fee. Washington said no thanks.

In the film business, timing and money is everything.  The Scott-Washington-John Travolta train tale The Taking of Pelham 123 so far has posted an unglamorous $60 million gross, which doesn’t give Washington much backbone to pull his usual salary.  Studios are trying to cut costs wherever they can and films that are not branded as a summer blockbuster are experiencing a tight budget pinch from the studios. Some actors and directors are willing to take pay cuts or defer.   Washington declined to take a pay cut and is seeing what else is out there.

(Source)