In the fall of 2004 approximately 1500 residents of New York City were interviewed by telephone, in English and Spanish, concerning hurricane evacuation. The interviews were part of an update to the New York City Hurricane Evacuation Study, and the telephone interviews comprised the Behavioral Analysis portion of the study. Questions dealt with

• · hurricane awareness

• · preparedness

• · sources of information

• · perceived vulnerability, and

• · evacuation intentions.

The behavioral analysis is designed to provide data used by the transportation and shelter analyses in the hurricane evacuation study. It also provides information for emergency management officials to help them formulate operational plans and public education efforts.

More than 300 interviews were conducted in each of the five boroughs of New York City. The city’s hurricane evacuation plan designates three zones that would be told to evacuate in various hurricane scenarios, called zones A, B, and C. In general the zones correspond to areas that would be told to evacuate in category 1, 2, and 3 hurricanes, respectively, due to possible flooding from storm surge, although factors such as storm track and forward speed could cause there to be deviation from that generalization. Within each borough interviews were conducted in each of the evacuation zones and also in areas inland of any of the zones, i.e., areas that would not be told to evacuate in hurricanes of any intensity (except for substandard housing). New York City Office of Emergency Management provided a list of streets and address ranges within each evacuation zone for each borough. A reverse-listing telephone directory was used to look up phone numbers of residences on a sample of those streets. The number of interviews in each zone in each borough depended on the portion of the borough in each zone, with more emphasis placed on Zone A due to its greater vulnerability and more frequent need to evacuate.

A series of questions were designed to ascertain the extent to which residents were familiar with hurricane evacuation and emergency management information. The city had produced a document called “Ready New York” and distributed it widely in several languages. The publication dealt with multiple hazards, including hurricanes, but also provided general household preparedness guidance that could be applied to a range of hazards. The booklet was described and respondents were asked if they had ever seen it. Few people said they had seen the publication. Affirmative responses ranged from 7% in Brooklyn to 15% in Manhattan.

A majority of respondents in all boroughs and all risk zones said they had internet access, although 25% to 40% said they did not. Approximately 20% of the overall sample said they had visited the city’s web site, NYC.GOV, to look up information about preparing for emergencies.

The city’s hurricane evacuation zones were described and interviewees were asked if they knew whether they lived in one of the zones. Only in Zone A of Queens did a majority of people say they knew if they lived in an evacuation zone. Those who said they knew whether they lived in an evacuation zone were then asked which zone they lived in (A, B, C or none). A majority of people in all zones stated that they didn’t know which zone they lived in.

Respondents were also asked to rate their familiarity with the location of hurricane evacuation zones in New York City (not specifically their own). Except in Zone A of Queens, most people said they were not familiar at all (versus very familiar or somewhat familiar) with location of the zones. Residents of Manhattan, Brooklyn, and the Bronx said they were least familiar with the zone locations.

Interviewees were asked if their family had a definite plan for deciding whether to evacuate and where to go if a hurricane threatened. Only in Zone A of Queens did close to half the respondents say their family had a definite plan.

New York City recommends that residents prepare a “go bag” containing items that might be needed in an evacuation. Go bags were described to respondents, and approximately 25% said they currently had go bags prepared. The city also recommends that residents have an emergency supply kit containing items allowing them to survive in their home for at least three days after a hurricane or other disaster. Emergency supply kits were described, and almost half the respondents said they currently have one.

People were asked if they had identified the safest location in their home or building to ride out a strong hurricane if they had to. More than half of those interviewed said they had identified such a location.

A list of information sources was read and respondents were asked how much they anticipated relying on each source for information about a hurricane that threatened New York. Most people expect to rely mainly on local radio and television, followed by The Weather Channel (TWC). Only 20% anticipating relying a great deal on the internet, including the city’s web site. There was little variation among boroughs or risk zones.

In most communities evacuation in a hurricane is influenced by whether people believe they would be safe staying in their own home during a hurricane that strikes their location. New York City respondents were presented with three hypothetical hurricane threats and asked how they believed their homes or buildings would be affected by each. The storms and their hazards were described as they are likely to be described by officials and the media if real storms actually threatened (wind, storm surge, waves, erosion, Saffir-Simpson scale). For each hurricane, interviewees were told to assume that the storm passed directly over their location, and then they were asked 1) whether the storm would cause water from flooding to enter their home or building, 2) whether the storm surge or waves would be severe enough to pose a serious danger to their safety, and 3) whether it would be safe to stay in their home or building, considering the effects of both wind and water.

Category 1 Hurricane

Only in the A zone in the Bronx did a majority say a category 1 storm would cause their home or building to flood. On average, only a third of Zone A residents said their dwellings would flood. That figure was only slightly higher than in Zone B, and 20% of the people in Zone C and in non-surge areas said their homes or buildings would flood. Only 19% of the Zone A respondents said they would experience dangerous flooding in a category 1 storm, which was only slightly higher than in less vulnerable zones. Queens and Bronx Zone A residents perceived their flood risk to be higher than those in other locations. Considering both wind and water, 31% of the Zone A residents said it would be unsafe to stay in their homes or buildings in a category 1 hurricane. In other zones the figures ranged from 17% to 23%.

Category 2 Hurricane

More than half the Zone A residents said their homes or buildings would flood in a category 2 hurricane, but only 40% of those living in Zone B held that belief. In both zones Queens and Bronx respondents were more likely than others to expect flooding. A third of the people living in Zone C and in non-surge areas expect flooding in a category 2 storm. Overall only 43% of the Zone A respondents said a category 2 storm would cause dangerous flooding in their homes or buildings, with a majority giving that response only in Queens and the Bronx. Queens was the only borough in which a majority of Zone B respondents expected dangerous flooding. Zone C and non-surge residents were about as likely as Zone B residents to anticipate dangerous flooding in a category 2 hurricane. Considering both wind and water, almost half the Zone A interviewees said their homes or buildings would be unsafe in a category 2 storm. Majorities gave that response in Zone A of Queens and the Bronx. Only 36% of the people in Zone B said their homes would be unsafe, which was only slightly higher than the response in Zone C and in non-surge areas.

Category 3 Hurricane

Flooding is more widely anticipated in all risk zones, but even in Zone A, a third of the residents either don’t believe their homes or buildings would flood or don’t know whether they would flood. As in other storms, Queens and the Bronx residents are more likely than others to anticipate flooding. Non-surge residents are almost as likely as Zone C residents to expect flooding. Expectations of dangerous flooding are almost as high as those for flooding. Almost half the respondents in non-surge areas said they expect dangerous flooding in a category 3 hurricane. Although a majority of people in Zones A, B, and C believe their homes would be unsafe in a category 3 hurricane, a substantial number do not hold that belief. Almost half the respondents in non-surge areas believe their homes would not be safe in a category 3 hurricane. Some residents believe their homes would be safe even though they expect dangerous flooding.

Among boroughs, Queens residents believed themselves to be at greatest risk, followed by respondents in the Bronx. However, the differences between Queens and the Bronx and other boroughs was greater for flooding than for wind and water considered together. More importantly, differences among risk zones are less than one would expect. That is, although Zone A residents perceived themselves to be at greatest risk and non-surge residents perceived themselves to be a least risk, differences were surprisingly small. Many respondents in high-vulnerability areas believe they are safe, whereas many respondents in low-vulnerability areas believe they are unsafe.

Perhaps the most important variable to anticipate in an evacuation is the percentage of people who will evacuate. In hurricane evacuation studies this is referred to as the evacuation participation rate.

One variable normally important to explaining evacuation participation rate is whether people believe they heard evacuation notices from public officials. The pattern is similar to that observed when perceived vulnerability was measured: under response in high-vulnerability areas and over response in low-vulnerability areas. Fewer than half the Zone A residents said they expect to be told to evacuate in a category 1 storm, but more than a third in Zone B, Zone C, and non-surge areas anticipate being told to evacuate. In a category 3 storm, 72% of the Zone C respondents expect that officials will tell them to leave, but 77% of the people living outside of any evacuation zone believe they would also be told to evacuate in a category 3 hurricane. In general more people expect to be told to evacuate than believe they would be unsafe.

Intention to Evacuate

In each of the three hurricane scenarios, interviewees were asked if they would leave their home to go someplace safer. In the category 1, 2, and 3 storm scenarios, respondents were told that officials had issued an evacuation notice for zones A, B, and C, respectively.

A substantial majority of people said they would evacuate in each storm scenario. In fact, there was very little difference in the number of people saying they would leave in a category 1 (75%), a category 2 (81%), and a category 3 (85%). Also, almost as many people said they would evacuate in the non-surge area as in Zone A.

One perplexing result is that more people intend to evacuate than believe they would be unsafe staying in their home or believe officials would tell them to evacuate. This implies that many people intending to evacuate plan to do so for reasons other than personal safety, although the question was phased in a way that should have discouraged that response (“Would you leave your home to go someplace safer?”)

Type of Refuge

For each of the three storm scenarios, respondents were asked where they would go if they evacuated. They were asked whether they would go to a hurricane shelter operated by the city and Red Cross, the home of a friend or relative, a hotel or motel, or someplace else. The clear indication is that the great majority of people intended to go to a hurricane shelter or to the home of a friend or relative, with approximately 45% saying they would go to each. In stronger storms there was an insignificant increase in the percentage saying they would go to hurricane shelters. Residents of Queens and the Bronx were slightly less likely than others to say they would go to hurricane shelters. People evacuating from Zone A were less likely than others to say they would use hurricane shelters.

Effect of Reception Centers

Evacuation plans for New York City call for evacuees who plan to go to a hurricane shelter operated by the City and Red Cross to go to a reception center first, rather than having people go directly to a hurricane shelter. The reception centers would be easily reached by public transportation and some would have parking. At the reception center evacuees would be assigned to a hurricane shelter and transported to that shelter by bus or van. The plan was explained to people saying they would evacuate to a hurricane shelter, and they were then asked if they would still plan to go to a hurricane shelter, given that arrangement. Approximately 60% said they would still go to a hurricane shelter.

People intending to go to hurricane shelters were told that city officials encourage evacuees to stay with friends and relatives in locations outside the areas being told to evacuate. Then they were asked if they had friends or relatives in safe locations with whom they could stay in an evacuation, if necessary. More than 70% said they did have friends and relatives with whom they could stay.

Between 25% and 30% of the households interviewed said they had pets, except in Staten Island, where 43% had pets. There was no significant variation in pet ownership among risk zones. Pet owners who planned to evacuate to a hurricane shelter were asked what they planned to do with their pet when they evacuated. More than 80% in Manhattan, Brooklyn, and Staten Island said they would take their pets with them to the hurricane shelter. That figure was about 65% in Queens and the Bronx.

Respondents were asked if they were aware that hurricane shelters operated by the city and Red Cross don’t allow pets inside. Most people were not aware of the policy, but among those who were aware, almost 25% said they would take their pets to the shelter.

Intended Destinations

Interviewees were asked whether their evacuation destination was in their own neighborhood, elsewhere in their own borough, another New York City borough, elsewhere in New York State, or out of state. Almost 40% of those intending to evacuate said they would plan to go someplace in their own neighborhood. Another 23% said they would go elsewhere in their own borough. There was relatively little variation among boroughs and even less among storm scenarios. (More geographically specific destinations are available for use in the transportation analysis, if needed.)

Vehicle ownership varies greatly among boroughs, and in the Bronx it varies among evacuation zones. In households with vehicles, respondents were asked whether they would use their own vehicle in a hurricane evacuation, ride with a friend or relative, or use public transportation. The great majority said they would use their own vehicle. Vehicle owners planning to use their own vehicles were asked what they would do if public officials urged them to use public transportation instead of their own vehicle. In Manhattan, Brooklyn, and the Bronx approximately 65% said they would use public transportation. In Queens and Staten Island, just fewer than half said they would use public transportation. Respondents were asked how many vehicles they had available in their household that could be used in an evacuation and how many of those vehicles would be used. The vehicle per household figures does not include a reduction due to appeals by officials to use public transportation.

Respondents were asked if anyone in their household would need assistance in order to evacuate. Overall fewer than 20% said they would need assistance. In those households needing assistance, interviewees were asked whether the person would just need transportation or the person had a disability or medical problem that would require special assistance. Except in Manhattan, most households expect to provide the assistance from within the household or with the aid of friends and relatives.

In most locations formulation of behavioral assumptions for transportation modeling and shelter planning is accomplished by application of generalizations observed in a large number of hurricane evacuations in a variety of locations. Those generalizations are particularized and fine tuned for the study location with knowledge of local plans and circumstances, including behavioral survey data about perceived vulnerability and response intentions in the local population. In New York City there is less confidence than normal in applying the pattern of generalizations from other evacuations. The New York’s physical vulnerability differs from that of most locations where evacuations have been documented, response options differ somewhat, and the population has too little experience responding to hurricane threats to have developed a response culture. There are no relatively recent hurricane evacuations in the city to learn from.

Intended response data is known to have certain biases, and in inexperienced populations, its reliability is suspect. Nevertheless in New York, intended response data would be relied upon more than in most studies, because of the limitations on other methods. Unfortunately many of the responses, particularly the intended participation rates, are not credible.

A large percentage of survey participants said they would evacuate their homes in category 1, 2, and 3 hurricanes. Unfortunately people in areas that would not be told to evacuate were as likely to say they would leave as people in areas that would be told to evacuate. That would result in massive over-evacuation and consequent transportation congestion. The clogging of streets and public transportation facilities and the jamming of evacuation reception centers would be so great and occur so early that the condition would probably remedy itself. People would stop evacuating simply because they were unable to evacuate. Public officials and media sources would issue instructions in response to the difficulties that would also curtail some of the intended responses. By that time, however, people in areas needing to evacuate might not have time to do so.

Statistical analyses were conducted to find patterns of over and under response using demographic variables such as age, income, race, education, years of residence in New York City, type of housing, and height of floor in multistory housing. Analyses were also performed to find associations of over and under evacuation response with awareness and preparedness activities such as having seen “Ready New York,” visiting NYC.GOV for emergency preparedness information, having a definite family plan for evacuating, and having a go bag. Neither the demographic nor the awareness/ preparedness variables were strong indicators of evacuation intentions. The problem lies in at least three identifiable areas: misconceptions about 1) evacuations zones, 2) vulnerability, and 3) evacuation notices.

The biggest obstruction to having an efficacious evacuation response in New York is lack of familiarity with the evacuation zones, their boundaries, and the rationale behind them. At least 75% of the residents surveyed said they were not familiar at all with the evacuation zones. Among people who said they knew whether they lived in an area needing to evacuate, the great majority were unable to correctly identify which zone they lived in: Zone A 20% correct, Zone B 2% correct, Zone C 2% correct, Non surge 14% correct. Knowledge of zones is important not only so that residents will know whether they need to evacuate but so that evacuees will know where they need to go to be safe.

Related to misconceptions about evacuation zones are mistaken beliefs about vulnerability and whether one’s location will be told by officials to evacuate. Too few residents of the most at-risk areas believe they would be unsafe, especially in category 1 and 2 hurricanes. At the same time, too many people living in the least at-risk areas believe they would be unsafe. The problem is further exacerbated by false impressions about which areas would be told by officials to evacuate. Slightly fewer than half the occupants of Zone A expect to be told by officials to leave in a category 1 hurricane, while a third of the people living in non-surge areas think they would be told to leave. More than three-fourths of the residents of non-surge areas believe officials would tell them to evacuate in a category 3 hurricane.

Perceived vulnerability and expectations of evacuation notices were the strongest predictors of evacuation intentions. People who believe their homes would be unsafe were 21 percentage points more likely than others to say they would evacuate. People who said they expect officials to tell them to leave were 19 percentage points more likely than others to say they would evacuate.

New York City is not alone in having so many of its citizens have misconceptions about evacuation zones and the need to evacuate. Even in communities with much more hurricane activity and long standing, aggressive public education efforts, large portions of the population hold mistaken beliefs similar to those of New Yorkers.

In deriving recommendations about evacuation participation rates for planning, the following assumptions were made:

1. The high number of intended evacuations from areas not being told to evacuate will not materialize, at least partly because of the congestion that would result from substantial over response.

2. Either with improved public education efforts or with real-time information during an actual hurricane threat, more people will become aware of evacuation zone boundaries and the relationship of the evacuation zones to vulnerability.

3. If officials issue evacuation notices, they will do so in a manner that permits a majority of residents to understand whether the notice pertains to themselves or not.

4. Officials will explain the consequences of over response and urge residents to not evacuate unless they are at risk.

5. In zones needing to evacuate, New Yorkers will encounter the same encumbrances to evacuation, especially in category 1 and 2 hurricanes, that residents of other coastal areas encounter, and fewer will evacuate than intend to do so.

 

It is typical in hypothetical scenarios for survey respondents to overstate their reliance on hurricane shelters as evacuation refuges. The normal adjustment is to halve the intended shelter use figure. In New York a similar downward adjustment is justified due to the following information.

1. Approximately 40% of those intending to go to a hurricane shelter said they would not do so after hearing about the reception center procedure.

2. At least 70% of those intending to go to a hurricane shelter said they have friends or relatives in safe locations with whom they could stay.

3. Many pet owners planning to take their pets to hurricane shelters will not be allowed to do so.

It is also common during a hurricane threat for evacuees to be contacted by friends and family who extend unanticipated invitations to accommodate the evacuees in their homes. During an evacuation many evacuees become more aware of some of the less desirable aspects of hurricane shelters and decide on other alternatives.

Destinations

Geographical destinations will correspond fairly closely to those stated as intended destinations in the interviews. The percent going to destinations in the evacuee’s own neighborhood will be slightly lower than intended as some evacuees realize that the intended destination is no safer than the evacuee’s own residence.

Not all vehicles will be used in an evacuation. Evacuating households normally leave behind some vehicles (30% on average) so the family will not be separated more than necessary. In New York City if officials aggressively urge evacuees to use public transportation rather than their own vehicles, approximately half the evacuees will comply, further reducing the number of vehicles used in the evacuation.