Section 403 addresses the specific requirements for covered vehicle parking structures and open parking garages. Covered parking structures must include adequate natural or mechanical ventilation to remove carbon monoxide and other vehicle exhaust products. Ventilation must be capable of providing at least 6 air changes per hour in covered spaces or continuous ventilation at 0.05 cubic feet per minute per gross square foot. Mechanical ventilation systems must be equipped with carbon monoxide monitoring that activates fan operation automatically when concentrations exceed 35 parts per million. Automatic sprinkler systems are required throughout parking structures with specific application rates and coverage patterns appropriate for vehicle fires. Fire separation is required between parking structures and other occupancies, with 2-hour minimum fire-resistance ratings between parking areas and adjacent occupancies. Egress from parking structures must be clearly marked with luminous exit signs and emergency lighting. Vehicle ramps must have grades no exceeding 1 foot vertical per 8 feet horizontal unless designed for steeper grades with calculated friction coefficients. Structural design must account for vehicular loads including impact forces, with reinforcement sized for dynamic loading. Lighting must illuminate all driving surfaces, ramps, and pedestrian pathways to minimum 5-foot candles. Paint used in parking structures must be flame-spread rated to Class A. Open parking garages require less stringent ventilation but must meet egress and lighting standards.