The board shall adopt reasonable rules pursuant to which funds allocated to a project may be increased upon a subsequent application of the county, city, town, or transportation benefit district constructing the project. The rules adopted by the board shall consider the following factors: (1) The financial effect of increasing the original allocation for the project upon other urban arterial projects either approved or requested; (2) whether the project for which an additional authorization is requested can be reduced in scope while retaining a usable segment; (3) whether the cost of the project shown in the original application was based upon reasonable engineering estimates; and (4) whether the requested additional authorization is to pay for an expansion in the scope of work originally approved.