ABSTRACT
Costs = ADT ∗ N ∗ ((RL/CS − RL/NS) ∗ (HC + VC) + RL ∗ (CA − NA) ∗ AC) (1)
Where
ADT = Average Daily Traffic (vehicles per day) RL = length of affected roadway over which cars
drive (miles) CS = traffic speed during bridge work activity
(miles/hr) NS = normal traffic speed (miles/hr)
N = number of days of road work (days) HC = hourly time value of drivers ($/hr) VC = hourly vehicle operating cost ($/hr) CA = during construction accident rate per vehicle-
mile (#/vehicle-mile) NA = normal accident rates per vehicle-mile
(#/vehicle-mile) AC = cost per accident ($/accident)
The Life Cycle Cost Analyzer determines the annual average costs of the bridge deck alternatives during the service life. Since FRP bridge decks and concrete bridge decks have different life spans, the equivalent annual cost or annuity method was chosen as it can be applied for any combination of service life A and B. This approach was performed by determining a fixed study period based on the life of the girders and abutments. For the medium bridges, the study period can
range from 50-70 years while for large bridges the study period is 100 years. Based on the given study period, the average annual costs of the two bridge decks will be calculated and compared. In the program, the study period is determined based on the researcher judgment. For this case study, i.e. a medium size bridge, a study period of 70 years was assumed. The following assumptions were applied to enable this analysis:
1. Present values of maintenance cost are first obtained and then converted to average annual costs.
