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Place of Work

The data on place of work were derived from answers to long-form questionnaire Item 22, which was asked of a sample of the population 15 years old and over. This question was asked of people who indicated in question 21 that they worked at some time during the reference week. (For more information, see "Reference Week.")

Data were tabulated for workers 16 years old and over; that is, members of the armed forces and civilians who were at work during the reference week. Data on place of work refer to the geographic location at which workers carried out their occupational activities during the reference week. The exact address (number and street name) of the place of work was asked, as well as the place (city, town, or post office); whether or not the place of work was inside or outside the limits of that city or town; and the county, state or foreign country, and ZIP Code. If the person's employer operated in more than one location, the exact address of the location or branch where the respondent worked was requested. When the number and street name were unknown, a description of the location, such as the building name or nearest street or intersection, was to be entered.

In areas where the workplace address was coded to the block level, people were tabulated as working inside or outside a specific place based on the location of that address, regardless of the response to Question 22c concerning city/town limits. In areas where it was impossible to code the workplace address to the block level, people were tabulated as working in a place if a place name was reported in Question 22b and the response to Question 22c was either "yes" or the item was left blank. In selected areas, census designated places (CDPs) may appear in the tabulations as places of work. The accuracy of place-of-work data for CDPs may be affected by the extent to which their census names were familiar to respondents, and by coding problems caused by similarities between the CDP name and the names of other geographic jurisdictions in the same vicinity.

Place-of-work data are given for minor civil divisions (MCDs) (generally, cities, towns, and townships) in 12 selected states (Connecticut, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and Wisconsin), based on the responses to the place-of-work question. The MCDs in these 12 states also serve as general-purpose local governments that generally can perform the same governmental functions as incorporated places. The U.S. Census Bureau presents data for the MCDs in all data products in which it provides data for places. Many towns and townships are regarded locally as equivalent to a place, and therefore, were reported as the place of work. When a respondent reported a locality or incorporated place that formed a part of a township or town, the coding and tabulating procedure was designed to include the response in the total for the township or town.

Limitation of the data. The data on place of work relate to a reference week; that is, the calendar week preceding the date on which the respondents completed their questionnaires or were interviewed by enumerators. This week is not the same for all respondents because the enumeration was not completed in 1 week.

However, for the majority of people, the reference week for Census 2000 is the week ending with April 1, 2000. The lack of a uniform reference week means that the place-of-work data reported in Census 2000 do not exactly match the distribution of workplace locations observed or measured during an actual work week. The place-of-work data are estimates of people 16 years old and over who were both employed and at work during the reference week (including people in the armed forces). People who did not work during the reference week but had jobs or businesses from which they were temporarily absent due to illness, bad weather, industrial dispute, vacation, or other personal reasons are not included in the place-of-work data. Therefore, the data on place of work understate the total number of jobs or total employment in a geographic area during the reference week. It also should be noted that people who had irregular, casual, or unstructured jobs during the reference week may have erroneously reported themselves as not working. The address where the individual worked most often during the reference week was recorded on the Census 2000 questionnaire. If a worker held two jobs, only data about the primary job (the one worked the greatest number of hours during the preceding week) was requested. People who regularly worked in several locations during the reference week were requested to give the address at which they began work each day. For cases in which daily work was not begun at a central place each day, the person was asked to provide as much information as possible to describe the area in which he or she worked most during the reference week.

Comparability. The wording of the question on place of work was substantially the same in Census 2000, the 1990 census, and the 1980 census. However, data on place of work from Census 2000 and the 1990 census are based on the full census sample, while data from the 1980 census were based on only about one-half of the full sample.

For the 1980 census, nonresponse or incomplete responses to the place-of-work question were not allocated, resulting in the use of "not reported" categories in the 1980 publications. However, for Census 2000 and the 1990 census, when place of work was not reported or the response was incomplete, a work location was allocated to the person based on their means of transportation to work, travel time to work, industry, and location of residence and workplace of others. Census 2000 and 1990 census tabulations, therefore, do not contain a "not reported" category for the place-of-work data. Comparisons between 1980, 1990, or Census 2000 data on the gross number of workers in particular commuting flows, or the total number of people working in an area, should be made with extreme caution. Any apparent increase in the magnitude of the gross numbers may be due solely to the fact that for Census 2000 and the 1990 census, the "not reported" cases have been distributed among specific place-of-work destinations, instead of tallied in a separate category, as in 1980.

Means of Transportation to Work

The data on means of transportation to work were derived from answers to long-form questionnaire Item 23a, which was asked of a sample of the population 15 years old and over. This question was asked of people who indicated in Question 21 that they worked at some time during the reference week. (For more information, see "Reference Week.") Means of transportation to work refers to the principal mode of travel or type of conveyance that the worker usually used to get from home to work during the reference week. Data were tabulated for workers 16 years old and over; that is, members of the armed forces and civilians who were at work during the reference week.

People who used different means of transportation on different days of the week were asked to specify the one they used most often, that is, the greatest number of days. People who used more than one means of transportation to get to work each day were asked to report the one used for the longest distance during the work trip. The category "Car, truck, or van -- drove alone" includes people who usually drove alone to work, as well as people who were driven to work by someone who then drove back home or to a nonwork destination during the reference week. The category "Car, truck, or van -- carpooled" includes workers who reported that two or more people usually rode to work in the vehicle during the reference week. The category "Public transportation" includes workers who usually used a bus or trolley bus, streetcar or trolley car, subway or elevated, railroad, ferryboat, or taxicab during the reference week. Público is included in the "Public transportation" category in Puerto Rico. The category "Other means" includes workers who used a mode of travel that is not identified separately. The category "Other means" may vary from table to table, depending on the amount of detail shown in a particular distribution.

The means of transportation data for some areas may show workers using modes of public transportation that are not available in those areas (for example, subway or elevated riders in a metropolitan area where there actually is no subway or elevated service). This result is largely due to people who worked during the reference week at a location that was different from their usual place of work (such as people away from home on business in an area where subway service was available) and people who used more than one means of transportation each day but whose principal means was unavailable where they lived (for example, residents of nonmetropolitan areas who drove to the fringe of a metropolitan area and took the commuter railroad most of the distance to work).

Private Vehicle Occupancy

The data on private vehicle occupancy were derived from answers to long-form questionnaire Item 23b, which was asked of a sample of the population 15 years old and over. This question was asked of people who indicated in Question 21 that they worked at some time during the reference week and who reported in Question 23a that their means of transportation to work was "Car, truck, or van." (For more information, see "Reference Week.") Data were tabulated for workers 16 years old and over; that is, members of the armed forces and civilians who were at work during the reference week.

Private vehicle occupancy refers to the number of people who usually rode to work in the vehicle during the reference week. The category "Drove alone," includes people who usually drove alone to work as well as people who were driven to work by someone who then drove back home or to a nonwork destination. The category "Carpooled," includes workers who reported that two or more people usually rode to work in the vehicle during the reference week.

Workers per car, truck, or van

This is obtained by dividing the number of people who reported using a car, truck, or van to get to work by the number of such vehicles that they used. The number of vehicles used is derived by counting each person who drove alone as one vehicle, each person who reported being in a 2-person carpool as one-half of a vehicle, each person who reported being in a three-person carpool as one-third of a vehicle, and so on, and then summing all the vehicles. Workers per car, truck, or van is rounded to the nearest tenth.

Time Leaving Home to Go to Work

The data on time leaving home to go to work were derived from answers to long-form questionnaire Item 24a, which was asked of a sample of the population 15 years old and over. This question was asked of people who indicated in Question 21 that they worked at some time during the reference week and who reported in Question 23a that they worked outside their home. The departure time refers to the time of day that the person usually left home to go to work during the reference week. (For more information, see "Reference Week.") Data were tabulated for workers 16 years old and over; that is, members of the armed forces and civilians who were at work during the reference week.

Travel Time to Work

The data on travel time to work were derived from answers to long-form questionnaire Item 24b, which was asked of a sample of the population 15 years old and over. This question was asked of people who indicated in Question 21 that they worked at some time during the reference week and who reported in Question 23a that they worked outside their home. Travel time to work refers to the total number of minutes that it usually took the person to get from home to work each day during the reference week. The elapsed time includes time spent waiting for public transportation, picking up passengers in carpools, and time spent in other activities related to getting to work. (For more information, see "Reference Week.") Data were tabulated for workers 16 years old and over; that is, members of the armed forces and civilians who were at work during the reference week.

Aggregate travel time to work (minutes)

Aggregate travel time to work (minutes) is calculated by adding together all the number of minutes each worker traveled to work (one way) for specified travel times and/or means of transportation. Aggregate travel time to work is zero if the aggregate is zero, is rounded to 4 minutes if the actual aggregate is 1 to 7 minutes, and is rounded to the nearest multiple of 5 minutes for all other values (if the aggregate is not already evenly divisible by 5). (For more information, see "Aggregate" under "Derived Measures.")

Mean travel time to work (minutes)

Mean travel time to work is the average travel time in minutes that workers usually took to get from home to work (one way) during the reference week. This measure is obtained by dividing the total number of minutes taken to get from home to work by the number of workers 16 years old and over who did not work at home. The travel time includes time spent waiting for public transportation, picking up passengers in carpools, and time spent in other activities related to getting to work. Mean travel times of workers having specific characteristics also are computed. For example, the mean travel time of workers traveling 45 or more minutes is computed by dividing the aggregate travel time of workers whose travel time was 45 or more minutes by the number of workers whose travel time was 45 or more minutes. Mean travel time to work is rounded to the nearest tenth. (For more information on means, see "Derived Measures.")

Reference Week

The data on employment status and commuting to work are related to a 1-week time period, known as the reference week. For each person, this week is the full calendar week, Sunday through Saturday, preceding the date the questionnaire was completed. This calendar week is not the same for all people since the enumeration was not completed in 1 week. The occurrence of holidays during the enumeration period probably had no effect on the overall measurement of employment status.