The intent of this Lane Closure Strategy (LCS) is to establish uniform criteria and guidance for scheduling lane closures in Region 4. The LCS was formulated to strike an appropriate balance between delays to the traveling public in the work zone and the cost of construction and maintenance. It is applicable to single-lane closures (and multi-lane closures on six-lane roadways) related to construction and maintenance activities on roads controlled by the Colorado Department of Transportation. It is based on extensive data analyses and estimates of delays expected during lane closures. The LCS addresses weekday and weekend traffic demand and considers temporal variations in traffic volume occurring over a typical 24-hour period. The LCS also accounts for seasonal variations in traffic volumes. This is the 4th Edition of the Region 4 LCS and a full revision will occur again after 3 years.