  Traffic jams are an everyday hindrance to transport, and typically arise when
many vehicles have the same or a similar destination. We show, however, that
even when uniformly distributed in space and uncorrelated, targets have a
crucial effect on transport. At modest densities an instability arises leading
to jams with emergent correlations between the targets. By considering limiting
cases of the dynamics which map onto active Brownian particles, we argue that
motility induced phase separation is the precursor to jams. That is, jams are
MIPS seeds that undergo an extra instability due to target accumulation. This
provides a quantitative prediction of the onset density for jamming, and
suggests how jamming might be delayed or prevented. We study the transition
between jammed and flowing phase, and find that transport is most efficient on
the cusp of jamming.
