From kbtv4.tv:

For many Southeast Texans, the evacuation before Rita was just as bad as the destruction the storm left behind. Evacuees from this area spent countless hours locked in traffic, but the next evacuation should be different.
The evacuation process is a major concern for local officials running through a hurricane drill. Many people consider contraflow to be the answer, but it`s actually a last resort.
Contraflow (turning all lanes in the direction away from the danger zone) is efficient but comes with certain risks, according to Department of Transportation engineers. Contraflow can block emergency workers trying to get into the area that`s evacuating.
The transportation department hopes to avoid contraflow with EvacuLanes -- shoulders officially open for evacuations.
"Definitely, this is a lesson that we learned from Rita," says Marc Shepherd with the Department of Transportation.
Contraflow can work better on a major freeway system with frontage roads that can be used as the route back into the danger zone.
"But on US 69, there are no frontage roads," points out John Barton, district engineer with the Department of Transportation. "When it`s necessary to save live lives, to do that we will [use contraflow]. But until that time we`ll use the EvacuLane as our way to get people out of town quicker."
The Rita evacuation also provided a learning experience in terms of priorities.
Instead of waiting to evacuate those with special needs or no car, "address those up front, prior to the general evacuation. That is probably our top priority," says Deputy Chief John Owens with the Port Arthur Police Department.
Houston traffic presented major problems for evacuees from this area. Now the state has a plan to divert Houston evacuees in another direction.