No vehicle shall be driven to the left side of the highway (1) when approaching the crest of a grade or upon a curve or elsewhere in the highway where a free and unobstructed view of the highway ahead may not be had for a sufficient distance to insure driving with safety or (2) when approaching within one hundred feet of or crossing any intersection or railroad grade crossing. These limitations shall not apply on a one-way street or highway so designated by any traffic authority. Violation of any provision of this section shall be an infraction.