[chop]

Safe loads for clear solid ice are indicated below:

Thickness of Ice Load or Activity
in cm
< 1 3/4 < 4.5 STAY OFF
1 3/4 4.5 One person cross county skiing
2 5 One person on foot or skates
4 7.5 Snowmobile or smaller ATV, groups of people walking in a single line
7 17.5 A small car
8 20 A 2 1/2 tons truck
9 22.5 A 3 1/2 tons truck
10 25 A 7 - 8 tons truck
Note that ice strength is influenced by many factors

age - newer black ice is stronger than old milky
distance to shore - ice close to shore is weaker than ice farther out
river outlets and inlets - ice close to outlets and inlets is weaker
obstructions like rocks, trees and plants
water currents
cover of snow
This information must only be used as a general guide - KEEP OFF the ice if you are not absolutely sure.