Introduction 1.1 Report Objectives 1.1.1 The research titled The Prediction and Appraisal of Travel Time variability Urban Radial Routes is awarded by The Toray Science Foundation to Mr. Tri Tjahjono, lecturer and researcher staff at the Department of Civil Engineering of the University of Indonesia, Jakarta. This research has been started on September 2, 1993 for a 10 (ten) months period. The research contract is under the Lembaga Penelitian Universitas Indonesia (LPUI) on behalf the Toray Science Foundation. The Team members of this research are : Mr. Tri Tjahjono as principal investigator, Mr. Alan Marino and Mrs. Ellen S.W. Tangkudung. During this research are also helping by 2 (two) assistant-members and 45 field surveyors. 1.1.2 Briefly, the objectives of this research are: first, to understand the nature and causes of travel time variability and how to impose the traveler's perception and response in selected urban corridors; second, to produce an estimated travel time variation of both inter-vehicle variation and inter-period variation and; lastly, to propose an appropriate traffic management scheme that is able to reduce the travel time variability.