The rev counter or the tachometer is an instrument that measures the definite momentum the engine is rotating at. The Calibrated ‘1, 2, 3...’ In addition, marked ‘x 1000’, indicates the revolutions that should be read under the per minute. A tachometer is very useful for the driving the aid that can help an excellent driver for the maximize performances. It is economically as well as good for the life of the engine. Some of the tachometer is marked by the red line. It shows that one should not exceed the engine damage and it should be avoided. The electronic fuel is the injection of today, ensuring the engine can never be over revved. It is used in estimating the traffic volume and signals. The vehicle has sensors and conducts the torch run act, which will record the traffic data completely. These data are substituted at the detector loop data. To get the best result, you need to require the highest number of runs and the partiality in a day. It is expensive, space to the lower density of the loop data accuracy, and the low reliability of the loop detector for more than 30 percent of services has run the common practices.