FTA Oversight Procedures - Federal Transit Administration - U.S. ...

SCC-10.02 Earth Excavation
Although a unit cost of $10.50 per cubic foot (cf) was used in the project cost estimate for the earth
excavation, sponsor’s January 2006 Preliminary Cost Estimating Guidelines recommends a range from
$10.00/cy to $16.00/cy for earthwork quantities greater than 5,000 cy.
Consequently, a potential cost risk as high as approximately $1,291,000 [($16.00/cf - $10.50/cf) x total
quantity] is calculated when considering the estimated earth excavation quantity of 234,740 cy.
SCC-10.04 Guideway: Aerial Structure
Nineteen bridge structure estimates were prepared by Grantee using a detailed approach that included the
quantity and unit price of the major structural and bridge components . The steel, including structural
steel, reinforcing bars, and piling, and concrete were the major cost items in each estimate. The unit costs
for reinforcing bars (epoxy and non-epoxy coated) and the steel piling conformed to the sponsor
Preliminary Cost Estimating Guidelines.
The bridge estimates used $400/cy for Class A concrete and $600/cy for Class F concrete. The January
2006 Grantee Preliminary Cost Estimating Guidelines recommended the following ranges for these
concrete types:
Class A $350 - $700/cy
Class F $450- $800/cy
Thus, the estimate’s concrete unit costs fell with the recommended ranges, but at the lower end. [Note that
in this example, analysis is missing and leaves the reader questioning whether the costs should have been
adjusted higher.]
Likewise, the $2.25/lb for structural steel that was used in the bridge estimates compared favorably with
the January 2006 sponsor Preliminary Cost Estimating Guidelines of $1.80/lb to $3.00/lb. However, this
range of unit cost also translates into a substantial cost variance.
Although the structural steel and concrete unit costs were within the recommended ranges of Grantee
Guidelines, a potential risk is the current market pricing and volatility of steel and concrete unit costs.
Significant cost impacts can be realized if the high-end unit cost for both items is employed in the bridge
estimates. In an attempt to quantify this market risk, the higher end unit costs for Class A concrete
($700/cy), Class F concrete ($800/cy), and structural steel ($3.00/lb) were used in the bridge estimates.
Table V-2 compares the Preliminary Design Project Cost Estimate and the newly created estimates using
the higher structural steel and concrete unit costs.
[ Include Table V-2. Comparison of Bridge Cost Estimates, or similar as required.]
Given the above discussion concerning the structural steel and concrete unit costs, a potential cost impact
(or positive variance) of approximately $11.33 million exists. This represents 22.3% of the bridge costs
in the Preliminary Design estimates. Consequently, current market pricing for concrete and steel,
including structural steel, reinforcing bars, and steel piling, should be obtained to confirm any variances
with the respective unit costs, and the estimate updated to reflect these latest costs.
SCC-40.06 Concrete Sidewalk
OP 33 Capital Cost Estimate Review
Revision 0, June 2008
Page D-6