The purpose of this research was to demonstrate a road-compatible piezoelectric energy harvester (RPEH) that uses the energy to power self-powered sensors and vehicle indicators. The demonstrated RPEH (20 x 50 x 10 cm(3)) with 80 piezoelectric devices can efficiently convert mechanical energy stemming from the small vertical displacement (1.45 mm) from vehicles into electrical power. The maximum voltage is 113.5 V, the maximum current is 25.71 mA, and the maximum power is 661 mW (6.61 W/m(2)) at an impedance resistance level of 0.9 k Omega under a z-axial load. The high-power RPEH was initially installed at a highway rest area. The measured output performances of the installed module on the actual roadway in the test setup area were a maximum voltage of 196 V and output power of 2080 mW (20.79 W/m(2)) at a vehicle speed of 30 km/h. Tests of the RPEH module demonstrate its ability to measure temperature, strain, and leakage values in real time and the generated energy provides sufficient power to illuminate LED indicators. It was also found that the z-axial loaded piezoelectric devices with a two-end fixed beam provide high output power with low levels of vertical displacement, making it highly efficient and durable for actual highway energy-harvesting applications.