A Binary Cuckoo Search for Combinatorial Optimization in Multiyear Pavement Maintenance Programs

Table 1

Mathematical formulation nomenclature.

Variable	Description
	Total M&R cost over a planning period
	Average value of pavement performance over a planning period
	Combined value of performance and M&R cost
,	is length of the planning period; is the ordinal of
,	is number of pavement sections; is the ordinal of
,	is number of M&R activities; is the ordinal of
	Price (unit cost) for applying M&R activity to pavement section in year
	Decision variable, equal to 0 if pavement section do nothing in year , otherwise equal to 1
	Length of pavement section
	Width of pavement section
	Average PCI value of road network in year
	Average PCI minimum value of road network in year
	PCI after M&R activities for pavement section in year
	PCI of pavement section in year
	Resetting value of pavement performance after obtaining M&R activity
	PCI of pavement section in year
	Performance degradation of M&R activity adopted in previous year for pavement section s. It is an uncertain value
	Minimum budget funds for M&R activities in year
	Maximum budget funds for M&R activities in the planning horizon
,	Weights given to total M&R cost and pavement performance
,	Standardized versions of formulas (1a) and (2a)
,	Maximal and minimal possible values of
,	Maximal and minimal possible values of