The paving is block paving, with some blocks protruding almost an inch in a staggered pattern.
The paving fills the gap between the cycle path and the road, where it moves away from the edge of the road to avoid a telegraph pole.
To me, it looks like it is intended to prevent cyclists from attempting to merge with traffic pulling out of McMullen Road and instead to direct them towards using the pavement to either join Haughton Road heading into town, to cross Haughton Road and then proceed along either the road or the Riverside Path, or to cross McMullen Road and use the riverside path towards Mill Lane. However, there are no markings to indicate that this is the case.
My advice for anone heading down McMullen Road on the bike path who wishes to join the road traffic on Haughton Road would be to make use of the box junction just visible in the first photo, or the one slightly further up McMullen Road, to access McMullen Road while the traffic is stationary and then to proceed as normal. If you wish to access either of the off-road paths, use the pedesitrian crossings to do so, taking care to avoid other users.
It is possible to ride over the paving (I tried) but only at very slow speeds. Not recommended!