8 Although the mean CO concentrations modelled by TEM for aft ernoon journeys on foot were in line with those of Figo et al., a striking diff erence was noted when each of the three peak hours was considered singly (Fig. 2). 9 It can be observed that during the fi rst hour (H1) of the peak period, journeys on foot resulted in a considerably lower level of CO exposure. 10 Although levels for journeys on foot generally exceeded those modelled for car journeys during H2, during the last hour (H3) the levels for journeys on foot were again frequently far lower than for car journeys.
Chapter 82