This stretch of footpath / cyclepath by the foot of Maiden Castle hill-fort is narrow and tends to be very muddy. It's an extremely difficult site as the river banks had to be reinforced here recently. Whether any improvement is possible is hard to assess. In the meantime, it offers the full off-road biking experience on your way to work, should you so wish! There is a case for creating a through route on the other side of the river to avoid this stretch. See http://durhamuniversity.cyclescape.org/issues/897-improvong-route-from-university-to-belmont