Wisconsin Statutes Vehicles (Ch. 340 to 351) § 346.915. Following snowplows

(2)(a) The operator of any vehicle that is not a snowplow may not follow a snowplow closer than the following distances, if the snowplow is engaged in highway winter maintenance snow and ice removal, as described in sub. (1), and is using lamps described in s. 347.26(7):

(b) Paragraph (a) does not apply when overtaking and passing a snowplow, but the fact that the operator of any vehicle follows the snowplow more closely than permitted by par. (a) for one mile or more or follows more closely than permitted by par. (a) when the snowplow is moving at the maximum speed limit is prima facie evidence that the operator of such following vehicle is violating par. (a).

(c) Paragraph (a) does not apply to a snowplow that is stopped or standing in the highway.