The Wisconsin Department of Transportation will declare all highways across the state officially frozen effective Thursday. That means Wisconsin’s frozen road law will be in effect statewide. The law allows heavier loads for trucks hauling cross-cut logs as well as salt and sand for winter maintenance. According to WisDOT, the seasonal weight restrictions help protect the state’s roads. WisDOT and county personnel use forecasts and liquid-filled frost tubes beneath pavement to determine when roads are adequately frozen.