Proposed work presents a UHF (400-520 MHz) antenna with compact structure for mounting on to the roof of Auto motives such as Train and Hammers. It can also be employed with a ground plane (roof surface/rooftop) as it is considered advantageous because the desired direction of communication are mostly independent of the orientation of the vehicle. The proposed antenna is made up of the compact size to reduce the overall antenna dimension. The simulation is carried out by using CST Microwave Studio Program and the effect of the antenna parameters on the bandwidth will be investigated. It is easily embedded on the roof of the vehicle. Moreover, the proposed antenna has simple structure, low profile, easy fabrication and relative good bandwidth (BW). It is also shown that this antenna is nearly omnidirectional over a majority fraction of bandwidth.