over the baseline control periods.
This conclusion is based on two findings.
First, fewer people disobeyed the enhanced sign D, and second, as is shown in Table 2, the total number of passengers
decreased with sign D. This lower rate of ridership suggests that this sign reduced the number of people who would have used the elevator for travelling a short-distance but instead used the stairs. The second piece of evidence is not as strong as the first as actual stair use was not measured.