For older people mobility and participation in activities can be restricted both by individual factors and by the environment. The aim of this paper was to examine the longitudinal impact of measures taken in the outdoor environment on an ageing population. The following factors were examined on three occasions over a nine-year period: frequency of walking; differences in report on environmental barriers; and reported valuation of the outdoor environment; and how these relate to different characteristics. At the second follow-up, the respondents experienced more functional limitations and more were using mobility devices than at baseline. At the first and second follow-up, the respondents did not experience as many environmental barriers in their outdoor environment compared to baseline. However, frequency of walking and evaluation of the outdoor environment decreased in general between baseline and first- and second follow-up. A quite promising result from the study is that compared to people not using mobility devices, mobility device users were more likely to be frequent walkers at first- and second follow-up than at baseline. Likewise, at second follow-up respondents having functional limitations were less likely to experience traffic barriers than at baseline. In terms of accessibility, usability and mobility for an ageing population, the results are promising, showing that measures in the outdoor environment can possibly facilitate walking for those who are more fragile, even in a longitudinal perspective.