You've probably noticed the signs on the outlying parts of I-45, I-10, US 59, and US 290. Signs telling drivers that they're approaching a contraflow area that could be activated in the event of a massive hurricane evacuation.
"You're taking what would be two-way traffic, and making it one-way traffic away from the city."
Raquelle Lewis is with the Texas Department of Transportation, or TXDOT, which manages the contraflow program.
"Our formal plans for that are actually put in place to direct response and lessons learned from the Hurricane Rita circumstances."
Lewis says that 2005 storm was the last time contraflow lanes were activated on I-45 and I-10. Since then, there have been mandatory evacuations -- most recently during Ike in 2008. But none of those occasions resulted in enough traffic for the Department of Public Safety or Harris County officials to ask for contraflow lanes to be used.
Lewis says it’s not just traffic volume, but also where the storm is expected to land that can dictate whether and when both directions of a freeway are used to carry outbound traffic.
"The likelihood that we would implement contraflow on all of the facilities that are capable of being contraflowed simultaneously is pretty slim."
Lewis says it can take up to six hours for crews to prepare a freeway for a contraflow shift. One reason is the sheer the length of the routes. For example, I-45’s main contraflow entrance is in the Woodlands, but it doesn’t end until drivers are 40 miles south of Dallas. All southbound traffic along that 170 mile stretch has to be cleared before northbound drivers can use it.
If a storm prompts the DPS to turn all lanes into outbound lanes, Lewis says drivers should prepare for fewer-than-normal opportunities to get on or off the freeway.
"There are some points within the plan that provide motorists to get off for food, relief, and gas. But they are strategic in terms of keeping the flow of traffic moving, and to minimize weaving so that traffic moves as efficiently as possible."
Notice how Lewis used the word “efficiently” instead of “quickly.” She says drivers in a contraflow situation should not expect to drive at normal highway speeds.
"This is not gonna be just like going outta town. This will be an emergency situation. It will be managed by state law enforcement, local law enforcement, to try to get people out of harm’s way. And that is the focus."
Lewis says the public can help minimize the need for officials to open the contraflow lanes by evacuating only when they’re ordered to. More information on contraflow lanes, maps, and diagrams can be found at traffic.houstontranstar.org/weather/hurricane_season.html.