Before-and-After Field Investigation of the Effects on Pollutant Emissions of Replacing a Signal-Controlled Road Intersection with a Roundabout

Table 12

Descriptive statistics for emissions (mg) by intersection type (traffic condition = peak).

Intersection	Number of trips	Mean	SD	Median	(Q1–Q3)	CV%
Signalized	153	63.42	48.01	58.22	(23.14–93.01)	75.7
Roundabout	139	89.67	56.23	79.69	(44.26–125.86)	62.7
Total	292	75.92	53.62	65.47	(34.13–109.97)	70.6