Under this subpart the Federal Highway Administrator may approve on any Federal-aid system projects which facilitate the use of high occupancy vehicles and public mass transportation systems so as to increase the traffic capacity of the Federal-aid system for the movement of persons. Eligible projects include:

(a) Construction of exclusive or preferential high occupancy vehicle, truck, or emergency vehicle lanes, except the construction of exclusive or preferential lanes limited to use by emergency vehicles can be approved only on the Federal-aid Interstate System;

(b) Highway traffic control devices;

(c) Passenger loading areas and facilities (including shelters) that are on or serve a Federal-aid system; and

(d) Construction or designation of fringe and transportation corridor parking facilities. For parking facilities located in the central business district the Federal-aid project must be limited to space reserved exclusively for the parking of high occupancy vehicles used for carpools or vanpools.