They had been traveling as embedded reporters with the 4th ID, but on this trip they were in a convoy of both Iraqi and US forces. It appears they were trying to develop a 'good news' story about the development of the Iraq force, when they were injured.
It was a propaganda mission.
Bob Woodruff was in Baghdad for ABC reporting the good news that the Bush administration complains is ignored by the news media, and he ended up as a glaring illustration of the bad news.
ABC News Iraq