Resultant traffic scores were divided into tertiles, and sampling homes were selected to represent the observed range of traffic scores and neighborhoods.
Candidate homes were geocoded using U.S. Census TIGRE files and City of Boston street parcel data, and initial traffic scores for each home were assigned using Massachusetts Highway Department MHDD) traffic volume data.
Due to unbalanced cohort recruitment in the study's early stages, additional non-cohort participants were recruited to capture a wider range of traffic scores, and neighborhoods where further recruitment was anticipated were over-sampled.
Across the entire urban core, 100-meter kernel-weighted traffic scores ranged from 0 to 3,305 vehicle miles traveled (VMT) per m2 per day; at cohort homes, this measure ranged from 5.8 to 168 VMT/m-day.
As we anticipated first-order (Gaussian) decay of key pollutants in the first 100 300 meters near major roadways [ 15], we opted to create initial traffic scores for site selection by applying a kernel weighting function to total traffic counts for all road segments within 100 meters of the home.
The total traffic light score ranged from Gold (outstanding care), to Green (high standard of care), Amber (good care but areas for improvement) and Red (falling short of optimum care and requiring major improvements).
The highways, however, are congested with heavy traffic, including scores of increasingly common Japanese cars, the choice of Nigeria's middle class.
Unlike attempts by other cities to revive their downtowns by closing major streets to traffic, Denver scored a major success and created a new public square with its 16th Street Mall.
Since its debut, Amazon has been steadily rolling out updates, including the addition of Pandora as well as traffic, sports scores and schedules, for example.
