5% Theoretical Cost Estimate

In certain cases, where an existing at-grade public crossing with active warning devices is being replaced with a bridge and federal funds are used, the railroad or another
local government
 will need to participate in the project funding. See
Title 23, Code of Federal Regulations, Section
 646.210 for details. This theoretical cost will be based on the following design criteria:
  • The approach roadway geometry will be designed using the minimum design criteria allowed for the functional class and annual average daily traffic (AADT) of the subject roadway (i.e., minimum k-values, design speed, grades, vertical clearance, etc.). Approach roadway for the theoretical structure will terminate as soon as the grade has returned to existing roadway profile.
  • The bridge length will be the minimum length possible to fully span the railroad right of way. Any other features that would need to be spanned based on actual conditions (ie., other roadways, waterways, etc.) are not considered.
    Only a bridge overpass will be considered for the theoretical structure, even if an underpass is ultimately proposed for the actual project.
  • The bridge superstructure type for the theoretical structure will be the same as for the proposed bridge span crossing the railroad right of way.
  • The width of the theoretical structure will be the same as the proposed bridge width if the number of lanes
    remains
     the same as the number of lanes on the existing grade crossing. If the proposed bridge has more lanes than the existing grade crossing, the theoretical structure will be the width of the proposed bridge minus the width of the number of extra lanes for the proposed bridge.
  • If retaining walls are used for the proposed bridge to limit the amount of embankment, retaining walls will be used for the theoretical structure.
  • Other design features required for the proposed structure, such as culverts, illumination, attenuators, riprap, etc., will be included with the theoretical structure.
The geometry of the theoretical structure will be presented as a .pdf file which contains an elevation view showing vertical geometry of the structure and approaches, and a typical section showing the theoretical bridge cross-section.
The bridge engineer will prepare
 an estimate in spreadsheet form based on the quantities for the theoretical structure. Costs for each item associated with the theoretical structure should be similar to a current project estimate. If no current project estimate is available,
use the most recent
 statewide average low bid unit prices.
If the highway or rail line is relocated to eliminate the at-grade crossing, the 5% theoretical cost will be the lesser of:
  • Actual cost of relocation project.
  • Estimated cost of relocation project.
  • Estimated cost of a theoretical overpass as described above.
Upon substantial completion of the project, RRD is notified by the district, and a letter is sent to the railroad for payment. The payment is received and processed by FIN. These funds are typically used to offset the federal obligation of the project by the same amount. Substantial completion is typically when the at-grade crossing is closed, and traffic moved to the grade separated structure.