TRB’s Transit Cooperative Research Program (TCRP) Synthesis 109: System-Specific Spare Bus Ratios Update documents successful practices in the United States and Canada, and presents information on efforts employed to achieve optimal bus fleet size and effective spare bus ratios. The synthesis is designed to provide guidance to transit agencies on how various factors may affect optimal fleet size.
Appendix D: Compilation of Agency Survey Responses was not printed not included in the print or PDF version of TCRP Synthesis 109. It is, however, available for download from this site.
TCRP Synthesis 109 updates the findings of TCRP Synthesis 11: System-Specific Spare Bus Ratios, as significant changes have occurred in the transit industry since 1995.