Population changes, weather, and congestion: Exploring declines in use of Chicago’s elevated trail

This research note examines possible explanations for declines in use of Chicago’s 606 Trail between 2016, its first complete year of operation, and 2018. Hypotheses include population changes near the trail, adverse weather in 2017-2018, and congestion effects. To evaluate these hypotheses, respectively, we use Census data, traffic counts, weather data, and regression modeling; and level-of-service (LOS) grades for peak use periods. We show that population changes were unlikely to have contributed to the use reductions and that, after controlling for weather effects, daily use still was significantly lower in 2017-2018 relative to 2016. Although LOS grades of “F” characterize much of weekend daytime use in summers, use reductions also occurred during periods with better LOS. None of the hypotheses fully explains the use declines. Field surveys are needed to explore additional, potential explanations including changes in preferences and perceptions of residents in gentrifying neighborhoods and the loss of a novelty effect.