Magnitude of Construction Cost and Schedule Overruns in Public Work Projects

Table 4

Mean and median values of construction cost overrun by project factors.

Project factors	Categories	No. of projects	Construction cost overrun (%)
			Mean	Median	Standard deviation
Project types	Flood control	83	3.04	0.00	8.87
	Transportation	236	3.23	0.17	5.99
	Utilities	44	1.27	0.00	4.33
Project size	Less than $1 million	135	1.67	0.00	5.83
	$1 million to $5 million	128	3.55	0.76	5.59
	Greater than $5 million	100	3.92	1.75	8.38
Project construction duration	Less than 1 year	279	2.46	0.00	5.85
	Greater than 1 year	84	4.59	2.12	8.54
Project completion year	From 1991 to 2000	185	2.66	0.00	6.69
	From 2001 to 2008	178	3.25	0.00	6.54
Total projects		363	2.95	0.00	6.62