234.112  School bus stops.--Each district school board shall establish school bus stops, or provide by school board rule for the establishment of school bus stops, as necessary at the most reasonably safe locations available. Where unusual traffic hazards exist at school bus stops on roads maintained by the state outside of municipalities, the Department of Transportation, in concurrence and cooperation with and upon request of the district school board, shall place signs at such bus stops warning motorists of the location of the stops.