24-hour traffic counts were collected using the Trax I Plus (JAMAR Technologies, Horsham, PA), on the highest-density road within 100 m of the home, during each sampling period when this was feasible (i.e., not during periods with snow/ice on the ground).
One limitation with this measure could be that we included only one road (the one with highest traffic density), but the overall low number of high-density roads in our study area could minimize this limitation.
In addition, higher minute ventilation was recorded in cyclists than car drivers in that study, especially on a high traffic density road.
Figure 4 shows the cumulative distribution function of the number of school children residing within a certain distance from a high traffic density road for both the parcel centroids and street geocoded locations.
In contrast to this pattern, we found that the activity of N. noctula, for instance, was positively correlated with insect abundance above fields surrounded by a relatively high density of roads (Fig. 3c).
In this case, the proportion of each biome's area transformed for human use, and the relative high density of roads indicate threat.
Outdoor air pollution comes mainly from traffic due to high density of roads and an international airport (first one in France after Paris airports).
Associations between PM2.5 and BP were stronger for persons taking medications, with hypertension, during warmer weather, in the presence of high NO2, residing ≤ 300 m from a highway, and surrounded by a high density of roads.
We investigated heterogeneity in the association between PM2.5 and BP by levels of traffic related exposures [living close (≤ 300 m) to a highway, surrounded by a high density of roads, high NO2 exposure], for levels of SO2 and CO, and for weather variables.
A review of existing studies concluded that "children living or attending schools near high traffic density roads were exposed to higher levels of motor vehicle exhaust gases, and had higher incidence and prevalence of childhood asthma and wheeze".
