Section 690-423 - Operation of diesel-powered equipment(a) General rule.--In addition to other requirements of this chapter, diesel-powered equipment shall be operated pursuant to the standards set forth in this section.(b) Attended equipment.--Diesel-powered equipment shall be attended while in operation with the engine running in underground mines.(c) Idling.--Unnecessary idling of diesel-powered equipment is prohibited.(d) Access.--Roadways where diesel-powered equipment is operated shall be maintained as free as practicable from bottom irregularities debris and wet or muddy conditions, which affect control of the equipment.(e) Speed.--Operating speeds shall be consistent with conditions of roadways, grades, clearances, visibility and traffic and type of equipment used.(f) Control.--Equipment operators shall have full control of the mobile equipment while it is in motion.(g) Traffic rules.--Traffic rules, including speed, signals and warning signs, shall be standardized at each mine and posted.(h) Maintenance.--(1) Diesel-powered equipment shall be maintained in a safe operating condition which does not threaten health of human beings.(2) Diesel-powered equipment not maintained in accordance with paragraph (1) or not maintained in accordance with the engine or emissions control operating specifications shall be removed from service immediately and shall not be returned to service until all necessary corrective actions have been taken.2008, July 7, P.L. 654, No. 55, §423, effective in 180 days [ 1/5/2009].