  The stochastic nature of public transport systems leads to headway
variability and bus bunching, causing both operator and passenger cost to
increase significantly. Traditional strategies to counter bus bunching,
including bus-holding, stop-skipping, and bus substitution/insertion, suffer
from trade-offs and shortcomings. Autonomous modular vehicle (AMV) technology
provides an additional level of flexibility in bus dispatching and operations,
which can offer significant benefits in mitigating bus bunching compared to
strategies available with conventional buses. This paper introduces a novel
alternative to stop-skipping by leveraging the new capabilities offered by AMVs
(in particular, en-route coupling and decoupling of modular units). We develop
a simple bus-splitting strategy that directs a modular bus to decouple into
individual units when it experiences a headway longer than a given threshold.
We then use a macroscopic simulation to present a proof-of-concept evaluation
of the proposed modular strategy compared to a benchmark traditional
stop-skipping strategy and the base (no control) case. We find that the
proposed strategy outperforms the benchmark in decreasing each of the three
travel time components: waiting time, in-vehicle time, and walking time (which
it eliminates completely). It therefore reduces the overhead of bus bunching
and thus the travel cost by more than twice as much as the benchmark for busy
bus lines. Simultaneously, it also reduces headway variability to a comparable
degree. Furthermore, we analyze different control thresholds for applying the
proposed strategy, and show that it is most effective when applied proactively,
i.e. with the control action being triggered even by small headway deviations.
