HOUSTON, Texas (KTRK) -- If you live in certain zip codes in Harris County, your home may fall into a hurricane evacuation zone.
In southeast Texas, certain zip codes are categorized into evacuation zones, known as "zip zones." Those zones are classified based on storm surge threat.
There are four zip zones: Coastal, A, B, and C. Hurricane evacuations are staggered to prevent gridlock on the highways.
Evacuation routes are designated roadways that provide the safest and fastest evacuation of coastal areas. Evacuation routes are updated annually before hurricane season.
If you live in Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston, Harris, Liberty, Matagorda, Montgomery, Walker, Waller or Wharton County, follow these evacuation routes.
Or, follow these evacuation routes per zip zone.
Evacuate only when local officials tell you to do so. Waiting until your zip zone is ordered will help reduce traffic and increase safety on the road for other evacuees.
Once the storm has passed, pay close attention to emergency officials' guidance on when it is safe to return. There may be hazards that need to be cleared.
Evacuation orders are issued by zip zone -- they are staggered to prevent gridlock on the highways.
The goal is to avoid a scenario like the mass evacuation and chaos ahead of Hurricane Rita in 2005. Millions of people, most outside of evacuation zones, hit the roads, and wound up stuck in standstill traffic for hours.
Ultimately, the mass exodous proved more deadly than the storm itself.
If you are in an evacuation zone, know your route out. If necessary, TxDOT and other emergency officials will convert inbound lanes to outbound lanes to accommodate for the extra traffic moving inland, called "contraflow".
Primary freeways in the Houston area include I-10, I-45, then some usage on US-290 and I-69. Evacuation lanes could also be used those are normally shoulders but can be used as driving lanes to help speed things up.