Cost Considerations and Staging
Cost Considerations
Cost for nighttime offpeak construction may be higher than for daytime construction. This is primarily because of additional required equipment (e.g., lighting trailers, standby equipment), nighttime wages (e.g., time-and-a-half wages) and perhaps the opportunity cost of the contractor (if equipment and personnel are tied up for many nights at an airfield job, they cannot be used elsewhere to generate income). This higher initial construction cost should be considered as one component in a comprehensive life-cycle cost analysis that would include, as a minimum (AAPTP project 06-06 develops life cycle cost analysis procedures for airfield pavements):
- Agency costs. Those costs incurred by the owner agency, such as:
- Initial construction
- Maintenance
- Rehabilitation
- Engineering
- Construction supervision
- Administrative
- Salvage value
- User costs. Those costs incurred by users of the airport, such as:
- Delays/cancellations due to work activities
- Normal everyday operation expenses (e.g., how they are affected by completing the work or not completing the work)
Given this approach, savings in user costs could more than offset the increased nighttime construction costs. For instance, during the Boeing Field rehabilitation of runway 13R/31L, the airport estimated user costs at $30,000 per hour that the runway was out of service.
Staging
Nighttime offpeak construction generally requires construction to be carried out at night and the pavement to be returned to operational service during the day. This requires construction equipment, sources of aggregate, fill, and other material to be staged to be staged off-site during daylight hours. This may involve allocating airport space or renting space in close-by areas. Stored equipment should be in areas that do not require tool control and have easy access because it is likely contractors will perform equipment maintenance during non-working (typically, daylight) hours.