I disagree!!!
No one that goes in a circle uses bead locks, They have too much air in their tires, only top fuel dragster do cause of the fact they air down to about 13 psi (depends on track temp, air temp, etc, and keeps the tire on the bead (hence the term bead lock)
First off, beadlocks are not DOT approved, that means they are illegal. The idea behind them is when you air down to a low PSI like 10 psi or less. the bead of the tire wants to fold over into the inside of the rim, which will cause a flat tire.
Instead of having the bead sit on the inside of the rim in a normal fashion, the bead is on the outside of the rim, and there is a plate that is secured over the bead with properly torqued bolts, squooshing the bead and locking it in place, so... when you air down and the tire has a nice sidewall buldge, the bead will stay secured to the rim as opposed to folding over.
I am unsure about other states but the reason for the illeagal status in massachusetts is cause they can cause very irrattic handling of the vehicle, bead lock wheels are almost impossible to balance for street use. so the vehilce has a tendency to dart side to side.