23 C.F.R. § 661.37
The following funding provisions apply in administration of the TTFBP:
(a) There are no funding limitations on an individual TTF bridge application, but the PE estimated cost will be based on the following fee scale:
Estimated Construction Cost:
Up to $1,000,000—Use up to 20% for PE
$1,000,000 to $5,000,000—Use up to 15%-20% for PE
$5,000,000 to $10,000,000—Use up to 10%-15% for PE
Over $10,000,000—Use up to 10% for PE