Notwithstanding Section 13340 of the Government Code, funds in the Highway Toll Revenue Account required to meet the obligations assumed by the commission under any bond resolution adopted pursuant to Section 31306 are continuously appropriated to the commission for that purpose. Upon appropriation by the Legislature, the commission shall allocate the remaining funds to the department for the purpose of constructing additional highways or making capacity enhancing improvements to existing highways to accommodate additional commercial traffic resulting from the North American Free Trade Agreement.