Does the effect of walkable built environments vary by neighborhood socioeconomic status?

<bold>Objective: </bold>To examine socioeconomic status as a moderator of the relationship between the built environment and active transportation such as walking or cycling using measures of built environment exposure derived from individuals transport trips.<bold>Methods: </bold>The 2008 Montreal Origin-destination (OD) survey provided origin-destination coordinates for a sample of 156,700 participants. We selected participants from this survey that had traveled within the census metropolitan area of Montreal the day preceding the interview, and that were between 18-65 years of age. Measures of connectivity, land-use mix, and density of business and services were collected using 400-m buffers of the trip routes. Logistic regression was used to model the relationship between built environment variables and active transportation.<bold>Results: </bold>Trip routes in the 2nd, 3rd, and 4th quartile of density of business and services or connectivity translated into greater odds of taking AT (compared to a trip in the lowest quartile). Trip routes in the 2nd, 3rd, and 4th quartile of land-use mix translated into lower odds of taking AT. Trips in the highest quartiles of connectivity and density of business and services were found to have a weaker association with active transportation if the individual undergoing the trip was from a low SES neighborhood.<bold>Conclusion: </bold>Our results suggest that previous studies finding no effect modification may have been due to the limitation of measurements of exposures to the residential neighborhood. [ABSTRACT FROM AUTHOR]