The findings of a current research project entitled Thermal Effects in concrete Bridqe Superstructures are highlighted. The research project is sponsored by NCHRP. A brief discussion of the mechanis¡ ns of heat transfer as they relate to bridge structures is presented, including the ther¡ nal coefficients of various types of different con-crete conposed of different aggregates. AIso inclualecl are brief discussions on nean effective bridge temperatures' temperature dífferentiats, and the response analysis for nonlinear temperature gra¿ lients. Two case studies of longitudinal thernal response selected from those conducted in the research project are íncLuded ín this paper. the thermal gradients used in Nev¡ zealand, England, and Ontario, Canada, plus those reconmended'by the Post-Tensioning Institute, are included in the response analy-sis. In addition, specific recon¡ nendations for inproving the US design provisions for thermal effects are included.