They addressed this same question on a special I was watching about the war not to long ago. It specifically dealt with a 6 mile stretch of road to and from the airport in Baghdad. The insurgents know specific roads/routes are important and our military knows that they must be secured.
The following excerpt may explain better than I can......
"The four-lane, six-mile stretch of road leading from central Baghdad to the country's main airport remains one of the most dangerous stretches of highway in Iraq, if not the world. It functions as a critical supply line into and out of the country, traversed daily by US military convoys as well as Iraqi and foreign businessmen, journalists, and aid workers.
So why is this vital strip of concrete, which takes only minutes to travel, still so difficult to protect?
One answer is that despite numerous US military checkpoints, the insurgents know that this is a "target rich" route that is the heart of military and contractor supply routes, and they continue to challenge every security measure devised."
I hope this helps Jimmo.
<small>[ December 09, 2005, 06:06 PM: Message edited by: Mermaid Sirena ]</small>