Covered humps next to the A1 Lt Paxton junction?

[tonyvid]

As you go northbound and just under the bridge for the Lt Paxton junction you can see a whole load of covered humps in the trees at the junction(so just opposite the Hail Weston ford road), any idea what they are?

I keep trying to peek but really should be looking forward at that point and not sideways!

[shaun442k]

MTB/BMX jumps.

[tonyvid]

Aha, thank you!

All I've ever seen there is odd shaped things covered with tarps and plastic.