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Carbon fiber reinforced polymer (CFRP) composites have been increasingly used in many vehicles such as airplanes, automobiles, and ships due to the advantages of high-strength, high-modulus, lightweight, and corrosion resistance. CFRP structures enhance the vehicle's performance, energy-efficiency, comfort, and safety. However, a common safety concern is how the CFRP materials perform when the vehicle is in fire and if there are enough time to safely evacuate the passengers. The elevated temperature can soften and decompose the polymer matrix, delaminate the CFRP laminate, and burn the CFRP through the contact with oxygen. As a result, the thermal and flammability response of CFRP is important for considering CFRP for vehicle applications; and some specialty high-temperature or flame/smoke/toxicity-proven resins have been investigated for CFRP parts manufacturing due to the needs. In this paper, a novel flame resistant hypothesis of utilizing the unique nano/micro- interlocked fiber reinforcing structure of the long-range carbon nanofiber z-threaded CFRP (ZT-CFRP) composite laminates for improving the flammability performance will be investigated. The carbon nanofibers (CNT) and carbon nanotubes (CNT), which have excellent thermal and mechanical properties, will be dispersed in an epoxy resin and will zig-zag thread through a carbon fiber fabric using an electrical/flow assisted impregnation process to create the unidirectional ZT-CFRP prepregs, respectively, which will be further processed into ZT-CFRP composite laminates. The UL-94 flammability test will be employed to characterize the ZT-CFRP laminates' flammability performance against the control baseline data of the regular CFRP, all without using any flame retardant chemicals. An impressive self-extinguishing flammability characteristic of the CNF based ZT-CFRP samples has been distinctly identified from all the samples. The UL-94 testing results and the effectiveness of using the long-range nanofiber z-threading strategy for enabling the novel nano/microstructure-induced flame resistant and self-extinguishing characteristics will be discussed.