Roundabouts with Unbalanced Flow Patterns Rahmi Akçelik Akcelik and Associates Pty Ltd PO Box 1075G, Greythorn Victoria 3104, Australia Phone: +613 9857 9351 Fax: +613 9857 5397 Email: rahmi@akcelik.com.au Paper presented at the Institute of Transportation Engineers 2004 Annual Meeting, Lake Buena Vista, Florida, USA, August 1-4, 2004 Revised: 25 August 2004 Right-hand version figures with US customary units and additional material included for some case studies (see the Appendix after references). Some data tables extended to include data in both metric and US customary units. Critical lanes in Table 5 are better identified, and Equation 4 corrected. Revised: 6 May 2005 Moore St and Fitzsimons Lane roundabout cases revised and US case results added in the Appendix (U-turns shown in figures for Moore St roundabout).