A self-coordinating bus route to resist bus bunching

The primary challenge for an urban bus system is to maintain constant headways between successive buses. Most bus systems try to achieve this by adherence to a schedule; but this is undermined by the tendency of headways to collapse, so that buses travel in bunches. To counter this, we propose a new method of coordinating buses. Our method abandons the idea of a schedule and even any a priori target headway. Under our scheme headways are dynamically self-equalizing and the natural headway of the system tends to emerge spontaneously. Headways also become self-correcting in that after disturbances they reequalize without intervention by management or even awareness of the drivers. We report on a successful implementation to control a bus route in Atlanta. (C) 2011 Elsevier Ltd. All rights reserved.