Around here the lakes are very common and mostly shallow, and the brush is thick. So aside
from ice fishing and skating, the lakes see a lot of vehcle and foot traffic.
The quality of the ice is a huge factor. 6" of bubbly ice might give way under you, but 1/2" of clear ice is plenty to walk on. If there is snow cover on the ice it will freeze very slowly, but bare ice can thicken very quickly. So, if conditions are windswept and snowy, assume thickness will not be uniform.