To effectuate the policy of the state declared in § 13b-226, such tax exemption projects shall specify for each such railroad those measures which the Commissioner of Transportation deems necessary in the public interest for the railroad to carry out during the calendar year following the date of issuance. Subject to the requirements of any applicable law or order of any regulatory agency having jurisdiction over such railroad, such tax exemption projects shall include one or more of the following:

(a) Railroad track or railroad facility improvement projects in this state. Allowable costs shall include design, inspection and construction of projects including, but not limited to, the maintenance, rehabilitation or construction of tracks, bridges, stations, or platforms or the acquisition or rehabilitation of equipment used exclusively in this state.

(b) Light density freight line service preservation, in this state, where the revenue and variable cost of such lines create the potential for abandonment. Such preservation means the railroads’ assumption of the deficit cost of the operation of such a line and shall be defined as one hundred ten per cent of the variable cost to provide service, minus the revenues generated by such a line.

(c) Intercity rail passenger service expansion in this state. Such expansion means Amtrak’s assumption of the operating deficit directly attributable to the passenger train service which is additional to the service defined in the Amtrak schedule dated October 28, 1984.