Traffic Cone Weights?
A traffic cone can either be made a specific weight that is suitable for a particular job, or it can have weights put on top of the base in order to keep it down. Traffic cones may need to be a certain weight for a variety of reasons. It could be that you need them to stay up to high winds.
It could be that you need them to stay up even when hit by a car, though less likely. To explore the different weight options, first find out the weight of the cone and then the accessories they offer in order to increase the weight of the traffic cone and keep it down.