304.590.  Travel safe zone defined — doubling of fine for violation in — signage required. — 1.  As used in this section, the term "travel safe zone" means any area upon or around any highway, as defined in section 302.010, which is visibly marked by the department of transportation; and when a highway safety analysis demonstrates fatal or disabling motor vehicle crashes exceed a predicted safety performance level for comparable roadways as determined by the department of transportation.

  2.  Upon a conviction or a plea of guilty by any person for a moving violation as defined in section 302.010 or any offense listed in section 302.302, the court may double the amount of fine authorized to be imposed by law, if the moving violation or offense occurred within a travel safe zone.

  3.  Upon a conviction or plea of guilty by any person for a speeding violation under section 304.009 or 304.010, the court may double the amount of fine authorized by law, if the violation occurred within a travel safe zone.

  4.  The penalty authorized under subsections 2 and 3 of this section shall only be assessed by the court if the department of transportation has erected signs upon or around a travel safe zone which are clearly visible from the highway and which state substantially the following message: "Travel Safe Zone — Fines Doubled".

  5.  This section shall not be construed to enhance the assessment of court costs or the assessment of points under section 302.302.