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

Table 8

Descriptive statistics for CO₂ emissions (g) by intersection type (traffic condition = peak).

Intersection	Number of trips	Mean	SD	Median	(Q1–Q3)	CV%
Signalized	153	60.63	19.44	60.43	(45.42–78.21)	32.1
Roundabout	139	54.49	20.72	48.14	(39.75–63.79)	38.0
Total	292	57.70	20.26	53.98	(41.18–72.12)	35.1