bottom of an ambulance

[BRUTUS_T_HOG]

the static electricity ground sounds like thats what it is.

the other thing mentioned was snow chains.. buses stuff like that have automatic snow chains that swing under the tire in a circular motion. but it would have several chains on each side of the axle

[averagef250]

automatic traction chains: http://www.onspot.com/.

These are what I thought you guys were talking about.

[Thunderfoot]

automatic traction chains: http://www.onspot.com/.

These are what I thought you guys were talking about.

all the fire engines around here have these on them, you can here them jingle when they hit bumps in the road and sometimes hit the surface...