On a wet or icy road, why must a tank vehicle driver be even more cautious than usual?

Slippery surfaces are especially hazardous for tank vehicles because low traction multiplies the existing risks of surge and a high center of gravity. A surge that pushes the rig forward during braking is far more likely to cause a skid when the tires cannot grip, and a skid in a high-center-of-gravity vehicle can become a rollover or jackknife. The driver should slow well below the normal safe speed, increase following distance further, brake gently and early, and avoid any sudden steering or braking. Anticipating stops and turns long in advance is the key to keeping a heavy liquid load under control on wet or icy roads.