WG2-Use of new technologies

The massive reduction in the cost of GPS services, the general reduction in size, weight, energy consumption and price of various measurement devices (e.g. GSM, accelerometers, pulse meters, and others) and the improvements in battery power enable conducting continuous monitoring studies of a longer duration (several days, weeks). The respondents are relieved of the more time consuming aspects of such studies, but retain control over their participation. The disadvantage of such passive monitoring studies is the absence of information about the purpose and social context of the observed travel. While it is surely feasible to conduct interviews close to the activity performance via telephone, web or personal visit, this increases the response burden through the additional scheduling efforts and time spent and could easily reduce participation rate in any so designed study.

Interview instruments, such as time use diaries, travel diaries, physical activity logs, mood probes, cover these aspects, but have well known problems of their own: missing episodes (activities, trips, tours), rounding of start and end times, misperception of the durations and distances, selectivity towards literate and very literate respondents, selectivity away from highly active respondents or also respondents with low mobility.
It is obvious, that robust methods of fusing the information obtained from different types of survey data, would considerably improve the accuracy of our understanding of mobility behaviour. As most current work is focusing on survey experiments, our proposal is to concentrate on the fusion of the data streams. The Action will draw on a number of countries for which large scale time use diaries, travel diaries, physical activity monitoring or GPS - based tracking data are available, such as Canada, UK, France, Germany, Switzerland, Italy or Sweden. The heterogeneity in the design and conduct of these studies is an advantage in our context, where such a situation is, up to now, the rule. Indeed, the perfect setup of simultaneous and harmonized design and conduct for all approaches is presently unlikely.