Radar can be used for vehicle speed detection application to reduce the number of traffic violation and car accident. One of its components is the antenna. In this paper, a design of 3×8 microstrip array antenna on Epoxy FR-4 substrate with a dielectric constant of 4.6 was developed. Antenna is designed and simulated using CST software. The working frequency is in the ISM Band of 2.4 - 2.5 GHz with return loss-10 dB. The simulation results show that the array antenna operates at frequency 2.35 - 2.53 GHz or bandwidth of 172.6 MHz. In addition, the antenna has a gain of 7.56 dB, horizontal beamwidth of12.5o, vertical beamwidth 52.6°, and the main lobe shifted to 36° toward ground. The measurement results show that the array antenna operates at frequency2.38 - 2.56 GHz or bandwidth of 177 MHz. Moreover, the antenna has gain of 7.1 dB, horizontal beamwidth of 14°, vertical beamwidth 56°, and the measured main lobe shifted to 28° toward ground.