This Memo interpreted the original intent of the Congress in establishing the Transportation Enhancement (TE) activities in the Intermodal Surface Transportation Efficiency Act of 1991:
Several field offices have asked whether the list of activities in Section 1007(c) is exclusive or illustrative. It is exclusive. Only those activities listed in Section 1007(c) are eligible to be accounted for as transportation enhancement activities. They are:
Many projects are a mix of elements, some on the list and some not. Those project elements which are on the list may be counted as transportation enhancement activities. For example, a rest area might include a historic site purchased and developed as an interpretive site illustrating local history. The historic site purchase and development would qualify as a transportation enhancement activity.
Activities which are not explicitly on the list might qualify if they are an integral part of a larger qualifying activity. For example, if the rehabilitation of a historic railroad station required the construction of new drainage facilities, the entire project could be considered a transportation enhancement activity. Similarly, environmental analysis, project planning, design, land acquisition, and construction activities necessary for implementing qualifying transportation enhancement activities are eligible for funding and may be counted toward the 10 percent requirement.
Source: FHWA Memo dated April 24, 1992