On busy lanes, where public transport buses are frequent, bus bunching is a common phenomenon:

Bunching leads to non-homogeneous utilization of buses and therefore degradation of service quality.

The objective is to (i) adhere buses to a timetable and (ii) guarantee equal headways.

The proposed control methodology is a shrinking horizon model predictive velocity control. 

Different control strategies are considered:
(i)    timetable tracking: buses prioritize the timetable over the headway reference.  
(ii)    headway tracking: buses try to keep equal headways.
(iii)    balanced: both objectives are equally important.

The controllers are simulated in VISSIM in a realistic traffic setting (Göteborg):

 The system was evaluated in the event of severe perturbation

(Xdes: desired position, Xref: reference position, ETD: estimated time of departure):

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