Traffic control spikes are most effective when combined with other parts of a security system that has been designed to your specifications and needs. You shouldn’t expect traffic control spikes to work in areas where vehicles go faster than 5 mph.

It’s also illegal to manufacture, transport, repair, or sell them. According to the Sheriff’s Office, the caltrops require specialty machinery to make.

These caltrops were either made by welding two pieces of wire together to form a four-pointed star or pouring molten steel into a mould to form a solid, seven-pointed star. The purpose of these devices was to disable horses. They were exchanged with French troops for bullets.

They are cheap, easy to deploy and, Pena says, very effective. “If you run over a caltrop, your tires will deflate,” he said. Caltrops also are indiscriminate. Those that do not puncture the tires of pursuing police cars sometimes puncture the tires of citizens’ cars.

Water Caltrops must be cooked as they are considered toxic when raw. After cooking, the pods are still very hard and can be cracked open to reveal the crumbly, starchy seed.

Caltrops do very little damage. However anyone who does get hit by them has their movement speed reduced, which is their main value.

It has killed or disabled innumerable soldiers, horses, camels, elephants and even land vehicles equipped with pneumatic tires.

Caltrops and other tire flattening devices are illegal weapons under the Texas Penal Code. A person is charged with a state jail felony if they intentionally or knowingly possess, manufacture, transport, repair or sell a tire deflation device.

Boiled Water Caltrops

1. Rinse water caltrops to clean them.
2. Place water caltrops in a saucepan and fill water until it covers them.
3. Add some salt.
4. Boil for 20~25 minutes.
5. Once cooked, drain the water and transfer water caltrops to a plate.
6. Use a pair of scissors to crack open the shell and dig the meat out with a knife.