  The ARRIVIAL problem introduced by Dohrau, G\"artner, Kohler, Matou\v{s}ek
and Welzl concerns a train moving on a directed graph proceeding along outward
edges according to the position of 'switches' at each vertex, which in turn are
toggled whenever the train passes through them. The problem asks whether the
train every reaches a designated destination vertex. It is known that ARRIVAL
is contained in UP $\cap$ coUP, while the previously best published lower bound
is that it is NL-hard. In this note we provide a simple reduction to the
$\mathsf{DIGICOMP}_\mathsf{EXP}$ problem considered by Aaronson. It follows in
particular that ARRIVAL is both CC-hard and PL-hard.
