Today's action extends the applicability of light duty vehicle and light duty truck durability procedures to beyond the 1998 model year. On January 12, 1993, EPA published a final rule establishing interim durability procedures used for demonstrating compliance with light duty vehicle and light duty truck emission standards, applicable in model years 1994-1996 only. On July 18, 1994, EPA published a direct final rule extending the applicability of the original rule to the end of the 1998 model year. Today's final rule extends the applicability of those durability procedures indefinitely. The Agency intends to conduct a separate rulemaking to implement a long-term durability program; however, such an action will be linked to other actions as part of a broad-based streamlining initiative for all vehicle emission compliance activities. It is difficult to predict with any precision when this subsequent action will occur. The Agency currently estimates that new compliance regulations will be promulgated such that they would become effective no earlier than the 2000 model year. Because the current durability regulations expire at the end of the 1998 model year, failure to adopt today's action would result in less effective and inefficient durability regulations beginning with the 1999 model year. The Agency believes that it is appropriate to extend indefinitely the existing interim procedures because so doing addresses lead time concerns for model year 1999 and beyond, accounts for the uncertainty of the anticipated revised compliance regulations and adds no new requirements, but rather simply allows the continuation of the current program.