Thanks for replying.
Eyeth said:
...Horizontal evacuation entails residents moving out of the coastal/flood-prone areas and into inland areas further away. ...
Oh yes, I know about those. We evacuated for hurricane Floyd. It was a nightmare! We made motel reservations for our family the day before we left Charleston. The
closest available rooms were in Knoxville, TN. It took us almost 20 hours to drive there (normally, it only takes 5 hours to drive there). Some people who tried to evacuate didn't even get out of the Charleston city limits because they sat in traffic so long (6-8 hours), and ran out of gas. Charleston is a very small city, on a peninsula, so there is only one way out.
There were no restrooms, no places to eat or get gas, for at least the first 12 hours. Some of us learned how to use empty "Big Gulp" cups for toilets. The highway area had to "bush" area for privacy. For many hours, our cars just sat on the highway, bumper to bumper. We turned off the cars, and stood around waiting. There was no police presence, no leadership, nothing. People helped each other.
Old people just sat in buses with no assistance. The old people (from nursing homes) were duct-taped into their bus seats. A few old people and one handicapped boy died.
When we finally got to a more open, moving area, residents stood along the streets and handed out bottled water and soda, free, to people driving by.
Finally, we got to an open gas station with a restroom. The line snaked out the building. One awful memory that sticks with me is a poor elderly man, standing in line for the restroom. He was trying to "hold" himself in, but he couldn't. He urinated thru his clothes, into his hands. It was such a dehumanizing experience. I still come to tears thinking about it, even now.
That's how bad it was, even with all the roads re-directed for exiting only.
Vertical evacuation would allow residents to move out of coastal/flood prone areas and into 'safer' areas within the same city or geographical region. South Florida is a good example of how this kind of evacuation has happened. People living in risky areas and housing would move into with their relatives and friends living in safer areas/homes. Moreover, shelters will open up for its residents.
That's a good idea in places that have sturdy high-rise buildings. We don't have many of those here. But I can see how parts of Florida could do that.
... Try driving around in Miami with no electricity; No traffic lights to direct traffic!
That would be a mess, true. It was hard enough doing that here after hurricane Hugo. No power for weeks. Most of the traffic lights were on the ground, and all street signs were blown away. We could hardly recognize streets and neighborhoods--it was like an unknown place. However, it was amazing how people helped each other. Even at multi-lane intersections, without lights, the traffic moved smoothly. People patiently took turns crossing intersections. In some places, people voluntarily guided traffic. After a while, the National Guard showed up, and took over traffic control.
As you say, there are pros and cons for both kinds of evacuation. I guess it all depends on the location.