This study compares Metropolitan Planning Organization (MPO) Regional Transportation Plans (RTP) and planning processes in selected regions of California. The study included seventeen MPOs in order to provide a balance of geographical location, growth rate, transit orientation size, density and air quality conformity status. Recommendations are presented for the following six areas: 1) public participation in the RTP process; 2) the frequency of updates; 3) scoring criteria for projects; 4) the use of planning data in the RTP; 5) coordination with ports and airports; and, 6) the evolving role of MPOs as it relates to the preparation of the RTP.