The manual entry about the Barrens:
The area to the west of the Slums is officially called Westview, but
more often referred to as the Barrens of the City. While the Slums are
a dirty, dilapidated place where hope seems a precious commodity, the
slums appear prosperous and bustling when contrasted with the Barrens.
The condition of the Barrens reflects a slow decay in the code
comprising the area. The Machines have been placing some effort into
repairing it, but the degradation serves the interests of several
powerful Exiles. Many buildings in the Barrens have fallen into such
disrepair that they have collapsed completely, but it is unlikely that
anyone will be successful in stemming the tide anytime soon.
I always assumed that the Machines had patched up a few things here and there, hence SOME good buildings, roads, etc. but that the Spectrum and other Exiles in the area hampered their efforts for their own gains.