Automated tall car park structures are modern alternatives to conventional parking structures to save space and volume in highly demanded parking regions in urban areas. -The design of such structures has significant knowledge gaps especially in regarding the effects of fire spread between passenger cars. The purpose of this study is to estimate the horizontal and vertical fire spread between passenger cars in automated tall car park structures and provide fire safety design to eliminate fire spread and possible structural collapse. The fire spread between cars is established by estimating irradiance heat flux of each car component. An 8-floor automated tall car park structure is designed in accordance with European standards. The results show that steel car pallets underneath cars reach to 1000 degree Celsius in early phases of fire, which could potentially cause a structural failure. Without any fire protection on the structure, the fire spreads to the neighboring cars in 25 minutes and to the cars above in 20 minutes. Significant fire protection is needed to eliminate fire spread between passenger cars. A more effective sprinkler system is also proposed to suppress the car fire.