Results from the Bureau of Transportation Statistics (BTS) Omnibus Household survey show that about three out of ten (28 percent) airline travelers reported experiencing what they considered to be significant delays while traveling by air in the month prior to the survey (Table 1). About one out of five travelers using personal vehicles (18 percent) or public transit (19 percent) reported experiencing significant delays during the same time period.
BTS surveys about 1,000 households on a monthly basis on a number of issues of interest to the transportation industry. Other results from the survey show that the total number of travelers reporting transportation delays rose from 33.5 million in November 2001 to 43.6 million in March and reached 53.6 million in July 2002. Delays for personal vehicles averaged 34 million travelers for the three months surveyed, making up 72 percent of all delays, largely because much higher numbers of people use personal vehicles than other modes of transportation (Table 2). Commercial airlines accounted for 12 percent of the total delays while public transit delays accounted for 11 percent. Other modes of transportation accounted for 5 percent of the total delays.
Survey results also showed that less than 10% of U.S. residents who experienced significant transportation delays opted to cancel their trips (Figure 1).
The most frequently selected options for dealing with the delays while traveling in a personal vehicle were to change the route (46 percent) or the time (35 percent ) of the trip.
Public transit passengers dealing with travel delays were most likely to change the time of their trip (41 percent) or select another mode of transportation (26 percent) while passengers traveling by commercial air were most likely to change the time of their flight (45 percent), change their route (20 percent), or postpone their trip (20 percent).
Data presented in this issue of OmniStats are taken from several issues of the BTS Omnibus Household Survey. Data are preliminary and are subject to change. The target population for the survey is the US non-institutionalized adult population (18 years of age or older). Results are based on a completed sample of 1000+ households that are randomly selected using a list-assisted random digit dialing (RDD) methodology. The findings summarized in this report are estimates derived from a sample survey. Sample surveys contain two major components of error-sampling and nonsampling error.
Sampling Error. Sampling error occurs because findings are based on a sample, rather than on the entire population. The total respondent pool for the Omnibus Survey is 1,000+ for an estimated sampling error of about ±3% at the 95% confidence level. Sampling error will be larger for sample subgroups (such as males or disabled persons) and for survey items that do not apply to all members of the sample (e.g. sample members who flew on a commercial airline during the 30 days prior to the survey). Standard error estimates for each Omnibus Survey item are available on the BTS website for the Omnibus Survey at http://www.bts.gov/omnibus/household/index.html. After selecting the month of interest, choose "Marginal Frequency Distributions."
Nonsampling Error. Estimates are subject to various errors during the survey process, such as data collection, response coding, transcription, and data editing errors. These errors would also occur if a complete census was conducted under the same conditions as the sample survey. Explicit measures of the effects of these errors are not available. However, stringent quality control procedures were followed during data entry and the questionnaire was reviewed and pretested in an effort to minimize nonsampling errors associated with data entry and questionnaire design. Nonresponse error is a function of both the nonresponse rate and the differences, if any, between respondents and nonrespondents