Showing posts with label preparedness. Show all posts
Showing posts with label preparedness. Show all posts

Saturday, April 18, 2009

Hurricane Preparedness: Evacuation vs. "Hunker Down"

When I proposed the alternative to tunnel I-45 (www.i45parkway.com) it was brought to my attention that I-45 could not be tunneled (among other opinions) because it was an emergency evacuation route. The Harris County Homeland Security & Emergency Management office has it shown on its web site along with evacuation zones. The same page also has a link to the I-45 Contraflow Routes and contraflow routes for I-10, US-290 and US-59.

As a registered professional engineering in the state of Texas my primary duty in the practice of my profession is public safety thus I invested hundreds if not thousands of hours considering emergency evacuation, in particular hurricane evacuation. The result was that tunneling of I-45 is a must. Here is why:
  • Current conditions of I-45 (downtown to Beltway 8) are sub standard, unsafe and lack capacity.
  • Federal process for development of highways takes 10 years which Houston cannot afford to wait.
  • Standard reconstruction of highways require traffic control that reduces traffic capacity. Reduced traffic capacity during an emergency evacuation route is likely not a good option.
  • Standard reconstruction of highways takes many years, i.e. I-10 took 8 years considering it had an additional 100-foot of right of way for expansion. I-45 does not have additional right of way.
  • I-45 north of downtown Houston floods during normal rain conditions, so does I-10.
Thus doing business as usual is a very risky process for residents of the Houston region, in particular those who have to evacuate before hurricanes. But why would a tunnel be a better option for expansion of a highway?
  • Construction is done below ground with little interference with existing traffic.
  • Allows connecting all major routes from US-59 south of downtown to Beltway 8 at Greenspoint.
  • Addresses the challenge to adding capacity to the Pierce Elevated.
  • Construction is less than five years.
  • Estimated cost for the proposed I-45 tunnels is about 5% more when considering construction time.
  • The I-45 (twin) tunnel proposal is designed for emergency evacuation and contraflow.
  • Highway tunnels are and can be designed as emergency shelters.
  • Highway tunnels can be constructed in Houston's soil conditions and are designed NOT to flood.
More importantly there are critical advantages of the proposed I-45 tunnels vs. the standard preferred alternative that was approved for the expansion of I-45:
  • The approved preferred alternative intends to reconstruct the existing I-45 and add one or three more lanes, from the existing (8 main lanes, 1 HOV lane, 4 service road lanes) to the proposed (8 main lanes, 2 or 4 HOV lanes, and 4 service road lanes). By Texas law only new lanes can be tolled, thus only the proposed HOV lanes could be tolled.
  • The proposed twin tunnel I-45 Tunnel/Parkway would add a total of 12 more new lanes to the I-45 corridor from south of downtown Houston to Beltway 8 at Greenspoint, most of it in District H.
Some obvious differences between the two include:
  • TxDOT's preferred alternative by increasing the number of lanes: increases width of pavement, does not prevent noise nor air pollution, does not provide significant added capacity to the corridor, allows toll revenue only on HOV lanes, increases the demand for floodwater detention, and may require right of way taking.
  • The alternative I-45 tunnels add 12 lanes: allows reconstruction of I-45 without the need for expansion, reduces or eliminates noise and air pollution, more than doubles the I-45 corridor capacity, it is a toll only facility, does not require flood mitigation, does not require additional right of way, and improves regional traffic flow.
What is unique about the I-45 Tunnel/Parkway alternative:
  • Doubles the corridor capacity
  • Provides traffic flow management through user fees
  • It is a world class engineering project, one of a kind
  • Provides a 100-year vision for the corridor
  • Allows development of the I-45 parkway with multi modal transportation uses (i.e. light rail)
Although the overall analysis of the I-45 Tunnel/Parkway concept is superior to any other proposes alternative for expanding I-45, including emergency evacuation, the analysis of the tunnel alternative as a hurricane evacuation route and emergency shelter was an introduction to a more comprehensive understanding of the regional approach to hurricane preparedness.

As a humble servant to the safety of the public, my understanding of hurricane preparedness plan in the Houston region consists of the following:
  • Evacuation zones identified as potential flood zones based on expected levels of surge caused by hurricane winds. These zones can be found in the Evacuation Map provided by Harris County.
  • The Houston region has identified roadways as emergency evacuation routes. I-45 is one of the principal routes for evacuating the Glaveston area and the 610 and Beltway 8 loops are used as traffic feeders/cconnectors to US-59, I-45, US-290, and I-10.
  • Outside the evacuation zones residents are expected to "hunker down" and ride out the storm/hurricane.
During the process of investigating evacuations and hurricane preparedness there are some concepts that perhaps need better determination and/or answers found. Here are some of them:
  • Coastal Community - Appears to be a federal designation of coastal areas expected to be evacuated in case of an emergency such as a hurricane.
  • Hurricane preparedness plan - Houston's plan appears to be based on potential for flooding but appears not to address wind forces.
  • Hunker down - The order given to the Houston region not included in the flood zones. It is equated to stay at home to ride out the storm/hurricane winds.
  • First responders - Who are the first responders and how are they and their vehicles protected from potential hurricane impacts?
  • Risk of flooding - Houston is prone to flooding. It appears that the potential for highway flooding, such as I-45 and I-10 north of downtown, is perceived to be small. How small? What is the likely that highways such as I-45 and I-10 be flooded for a short period of time prior or during evacuation orders? What is this probability over the next 10 years since it will take 10 years or more for I-45 and/or I-10 to be reconstructed?
  • Hurricane shelters - How many people and for how long will hurricane shelters be needed?
  • At-risk populations - Children, the elderly and low income families are generally the most affected by emergency situations like hurricane evacuations. How are they prepared?
Thus based on traffic engineering and highway design experiences; given the potential for the event of a hurricane; past event such as hurricanes Katrina, Rita, and Ike; and potential for highway flooding; what could be a possible emergency plan that could enhance and/or improve the current Harris County hurricane preparedness plan? Following are three suggestions:
  • Build the I-45 tunnels from US-59/288 south of downtown Houston to Beltway 8 at Greenspoint - Two objectives for this: one, to provide a better emergency evacuation route and two, to provide emergency shelter for at-risk population and emergency vehicles.
  • Develop a pilot program that builds future schools for dual purpose, improve education and provide emergency shelter - The proposed pilot program is to design a multi purpose education center that includes one or more of the following : school, community center, library, after school program, and play grounds or park spaces. These multi purpose education center is to be designed and constructed to withstand category 5 hurricanes and be sustainable to house communities over long periods of time. These could incorporate solar power energy which can be sold back to the grid and/or implement multi purpose green areas that could be used for recreation and flood management.
  • Implement a free program to rate all structures for hurricane categories - Partner with organizations such as the AIA to rate structure that could be used for hurricane protection in terms of category categories. New construction should also be rated for hurricane categories and home buyers be given the option to upgrade structures to higher hurricane standards.
The consequences for ignoring these three suggested approaches to protecting residents of the region could have catastrophic consequences. There are many lessons learned from hurricanes Katrina, Rita and Ike. There are many lessons learned from coastal communities that were significantly affected by Hurricane Ike such as Galveston where up to 30 percent of its population, about 15 to 20 thousand people, have been displaced. Most of these people are low income.

Below few links to remind what Katrina, Rita and Ike caused:
Collecting and Preserving the Stories of Katrina and Rita
Hurricane Katrina Editorial & Stock Image Archives
The Short But Eventful Life of Ike