TRB's National Cooperative Highway Research Program (NCHRP) Report 672: Roundabouts: An Informational Guide - Second Edition explores the planning, design, construction, maintenance, and operation of roundabouts. The report also addresses issues that may be useful in helping to explain the trade-offs associated with roundabouts. This report updates the U.S. Federal Highway Administration's Roundabouts: An Informational Guide, based on experience gained in the United States since that guide was published in 2000.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 328: State Product Evaluation Programs examines the general use of evaluation programs within state departments of transportation (including the use of state specifications, and laboratory and field testing results), the national programs that exist to support the integration of new products and technologies into practice, and the general issues associated with conducting objective evaluations of new products and implementation of approved products.