A. If the department adopts 49 Code of Federal Regulations parts 390 through 397 as a rule, a telecommunications corporation engaged in rendering public utility service or a railroad and its employees whose work necessarily involves the operation of a motor vehicle weighing more than eighteen thousand pounds gross vehicle weight rating but which operation is only incidental to the performance of their principal nondriving duties and purpose of employment are exempted from compliance with 49 Code of Federal Regulations parts 391 and 395, except that Title 49 of the Code of Federal Regulations, Part 391, subparts A and E apply unless it is the practice of the telecommunications corporation engaged in rendering public utility service or the railroad to assign regular drivers, qualified in accordance with 49 Code of Federal Regulations parts 390 through 397, to motor vehicles weighing more than eighteen thousand pounds gross vehicle weight rating, and if such driver becomes unavailable or unable to operate the motor vehicle on a given occasion due to an unavoidable or unforeseen circumstance against which provisions could not be reasonably made, compliance with 49 Code of Federal Regulations parts 391 and 395 is not required.

B. A person who is an employee of a public service corporation, a political subdivision of this state that is engaged in rendering public utility service or a railroad is exempt from any hours of service requirements at any time when relief assistance is needed to supplement state or local efforts and capabilities to save lives, protect against substantial loss of property, protect the public health and safety or lessen or avert the consequence of a catastrophe. If an emergency respondent independently identifies an occasion or instance that jeopardizes life or property or that endangers public health and safety, an emergency situation exists, and the respondent is exempt from any hours of service requirements if the respondent contacts with due diligence and coordinates with state or local officials.

C. The following intrastate drivers may begin to calculate hours of service requirements at any point at which the driver goes on duty after the driver has been off duty for twenty-four or more consecutive hours:

1. Drivers who are primarily involved in the transportation of groundwater drilling rigs.

2. Drivers used primarily in the transportation of construction materials and equipment en route to or from an active construction site that is within a seventy-five air mile radius of the driver’s normal work reporting location and is at a stage between initial mobilization of equipment and materials to the site and final completion of the construction project. This paragraph does not apply to drivers transporting hazardous materials in a quantity that requires placarding.

3. Drivers of public utility service vehicles that are operated primarily within the service area of the public utility’s subscribers, that are used in furtherance of repairing, maintaining or operating any physical facilities necessary for the delivery of public utility services and that are engaged in any activity necessarily related to the ultimate delivery of public utility services to the consumer, including travel to, from, on or between activity sites. The public utility is not required to be the owner of the vehicle.

D. For the purposes of this section:

1. "Public service corporation" means a public service corporation as defined in article XV, section 2, Constitution of Arizona.

2. "Railroad" means a railway or railroad that is regulated as a common carrier under article XV, section 10, Constitution of Arizona, and that is subject to Title 40, Chapter 4, Article 3.

3. "Telecommunications corporation" means an entity as defined in section 40-201 that is subject to regulation by the corporation commission.