Magnitude of Construction Cost and Schedule Overruns in Public Work Projects

Table 5

Mean and median values of schedule overrun by project factors.

Project factors	Categories	No. of projects	Construction schedule overrun (%)
			Mean	Median	Standard Deviation
Project types	Flood control	83	3.19	2.53	34.71
	Transportation	236	1.05	6.25	36.22
	Utilities	44	1.02	0.00	39.70
Project size	Less than $1 million	135	−11.23	0.00	43.37
	$1 million to $5 million	128	4.99	6.25	33.39
	Greater than $5 million	100	14.35	14.82	20.52
Project construction duration	Less than 1 year	279	−4.56	0.00	38.12
	Greater than 1 year	84	21.79	19.92	17.87
Project completion year	1991 to 2000	185	4.23	1.96	29.02
	2001 to 2008	178	−1.27	7.05	42.35
Total projects		363	1.54	5.06	36.23