40 cm, not too high, but I guess high enough to make you choose a way past them, without riding around them. Jump them, dismount and run over them, or crash into them.

If you can launch over them, that's great. But what if you blow it? You'll be down on the ground, possibly, with all the humiliation that can go with it, and possibly something broken or bruised.

Crashing into the barriers happens anyway, but usually not planned. What if you just keep pedalling and nail it hard? What will give first- wheel, fork, or barrier? I've heard at UCI events, the barriers are "staked" into position; that would be similar to hitting a wall, except you'd be able to go over the bars.

So, if you either don't make the hop or find yourself ramming the barrier at speed, should you let go of your bike during the crash onset? There's a chance you could pull off one of those miraculous crashes where you end up on the bike again and ride off, making it look like you meant to do it.

What would Ponytail Man do? When I crash, my bike seems to hit me in the back of the head somehow. Maybe I should hold on, and try to roll back up onto the seat and pedal off. I've got to learn that trick!