Speed bumps for park, best options?

I’ve got gravel roads.I see there are plastic rubber speed bumps for sale or I could have some concrete ones built. Any tips on the best option?

I’ve installed the rubber variety and they’ve held up pretty well. However, I think they attach with spikes and may require asphalt to secure them.

Speed bumps often cause more problems than they are worth. They will increase your chance of liability claims (“my car axle broke”, “I tripped over the speed bump” are two lawsuits I’ve had in a park) as well as cause negative behaviors, such as cars driving “around” the bumps, up into people’s yards and created a mud hole. On top of that, they will create huge negative comments from the tenants, who find them a nuisance.Your already have gravel roads, which are hard to speed on anyway. Why are you adding them?Post your speed limits and, if tenants are observed driving recklessly, threaten to non-renew their leases.I definitely would think twice before adding speed bumps to any park. 

Thanks guys. Frank, good info there. I’ve got a few bad apples that rip through and tear up the road. I’m evicting them anyhow.