(a) The head of your agency must make a determination in writing, valid for one year, that such use is appropriate and consistent with sound budget policy, and the determination must be kept on file;

(b) There is no safe and reliable commercial or duplicative Federal mass transportation service that serves the same route on a regular basis;

(c) This transportation is made available, space provided, to other Federal employees;

(d) Alternative fuel vehicles should be used to the maximum extent practicable;

(e) This transportation should be provided in a manner that does not result in any additional gross income for Federal income tax purposes; and

(f) Motor vehicle ridership levels must be frequently monitored to ensure cost/benefit of providing and maintaining this transportation.