Operation of any motor vehicle in a manner constituting a moving violation of any provision of this chapter in a highway work zone, as defined in § 46.2-878.1, when workers are present and when such highway work zone is indicated by appropriately placed signs shall be unlawful and shall constitute a traffic infraction punishable by a fine of not less than $300 for the first offense and not less than $500 for any subsequent offense. However, if any such subsequent offense occurs within the same 12-month period as any other moving violation of any provision of this chapter while operating a motor vehicle in a highway work zone, as defined in § 46.2-878.1, such fine shall be not less than $750. A prosecution or proceeding under § 46.2-878.1 is a bar to a prosecution or proceeding under this section for the same act, and a prosecution or proceeding under this section is a bar to a prosecution or proceeding under § 46.2-878.1 for the same act. Nothing in this section shall preclude the prosecution or conviction for reckless driving of any motor vehicle operator whose operation of any motor vehicle in a highway work zone demonstrates a reckless disregard for life, limb, or property.