Comparability — Canada [top]

In 2005 and 2010, the vehicle access question asks how often the diarist has a vehicle at his or her disposal: "All the time", "Some of the time", "Rarely", or "Never". Since this question does not ask about the number of vehicles in the household the responses "All the time", "Some of the time" and "Rarely" are coded as VEHICLE=3 (1 car or motorcycle) and the response Never is coded as VEHICLE=1 (no). Therefore, it is important to note that VEHICLE=3 sometimes also includes 2 cars or motorcycles, which should be coded as VEHICLE=4 if the data were available. VEHICLE=2 where there are episodes of bicycling and the data on other vehicles is missing or is =0 because bicycles are common types of transportation and more environment-friendly choices which should not be ignored even in the industrialized countries (though only nine changes were made for a person who has only bicycle but not cars/motorcycles).

Comparability — Finland [top]

In 1979, the diarist was asked whether he or she had an automobile ("yes" or "no"). Therefore, a positive response is coded as 1 car or motorcycle (value 3), however, some of these responses may include 2 or more cars or motorcycles.

Comparability — France [top]

1985 data do indicate ownership of horses or ponies, but all households which own a horse or pony also have other vehicles - there are no horse households with only animal transport.

Comparability — Netherlands [top]

For 1975, it is not possible to tell if household have more than one car. Respondents who ride a bicycle from home to other places and home but do not have a car are households that have access to a bicycle.

Comparability — United Kingdom [top]

In 1974, it is only possible to determine if the household has a car (and more than one car is identified by multiple car radios), but not possible to tell if those households without a car have a bicycle or horse.

In 1983, this information is inferred from modes of transportation reported in the diary.

In 2005, the only variables available note whether motorized vehicles are available or not, no variables mark access to bicycles and the like.

Comparability — United States [top]

In 1975, there is not a question about the number of cars, but there are questions about the number of motorcycles, bicycles, and parking spaces at the home, and the amount of money spent on car repairs. One quarter of the cases are missing data on all of these questions.

In 1992-94, the number of vehicles in the household is not recorded. However, questions related to vehicles are asked and this variable is constructed as follows. The survey asked if the diarist was in a garage when a household vehicle was started as well as whether the diarist walked outside to a vehicle on the driveway or outside carport. If respondents answer 'yes' to either of these questions they are coded as having a vehicle. Likewise, respondents who spend time using services at an auto-repair service are coded as having a vehicle. This definition produces 51% of households as owning vehicles, which is too low; this variable should be used with caution.