TRB's Transit Cooperative Research Program (TCRP) Synthesis 42: Use of Flexible Funds for Transfer Under ISTEA and TEA-21 reviews how current flexible funding provisions are being used to support transit investment and to examines lessons that may have the broadest relevance throughout the transit industry. The scope of the synthesis includes references to summary FTA data from FY 1992–2000, spanning the entire life of the ISTEA legislation and the first 3 years of TEA-21.