This is an appeal by way of trial de novo of a conviction of defendant Martin Schmiede for violation of N.J.S.A. 39:4-98 in the Bedminster Township Municipal Court. He was charged by a state trooper with driving at an average speed of 72 miles an hour on Interstate Highway 78 in Bedminster Township, a 60-mile an hour zone, on September 10, 1971 at about 3 P.M. A state trooper testified that he had clocked defendant over a 4.8-mile course at an average speed of 72.7 miles an hour by the use of an electronic device known as Vascar.
The questions presented are whether the Vascar unit is a scientifically accurate instrument; whether the state trooper
as an operator of that unit was adequately trained in its use, and whether the use of the device by the state trooper on this particular occasion was proper.
The State presented the testimony of the program manager for Vascar, which is manufactured by the Federal Sign and Signal Corporation. Defendant presented no expert witness. The court determined that the witness was qualified to testify with respect to the scientific basis for the operation of the Vascar unit. The expert testified that Vascar is a special purpose electronic digital computer set to accept increments of distance and time, computing the average speed to the nearest tenth of a mile an hour. Its principle is based upon the accepted formula that speed equals distance divided by time. It consists of three modules: the odometer module, which works directly into the transmission and is turned on by the speedometer cable activator; the control module, which is the control center operation for the Vascar operator, and a computer module, which is placed on the inside of the vehicle. Its power is obtained from the car battery.
The control module contains two switches, one for measuring distance and one for measuring time. The odometer module is geared to measure 6,000 pulses a mile, or one pulse for every 10.56 inches of roadway travel. When the distance is measured in this manner the distance can be locked into the device to await the time interval. The time interval is measured by switching the time switch on and off, and the time is computed by an oscillator which has a fixed rate of 170.7 cycles a second. Once the distance and time factor are fed into the computer module, an automatic reading to the tenth of a mile is flashed on the control module which will signify the average speed of the vehicle clocked over the distance traversed. The maximum distance that the unit will store is approximately 5 1/2 miles and the maximum time is 6 1/2 minutes.
The unit has an adjustment of the time factor by way of a screw on the control module which is used to calibrate the
instrument. The calibration is done by clocking in a fixed distance and a fixed time. Other than a changing of tires which would affect the reading, the calibration would not change more than 2/10ths of a mile an hour in a six-month period. Changing of tires requires calibration.
The Vascar device is used by determining two fixed points and measuring the time and distance between these points to ascertain the average rate of speed. The input may be either the clocking of the time first or the measuring of the distance first. In order to obtain an accurate setting of the unit on the target points, usually the shadow from a bridge or overpass is used to overcome problems of depth perception. The expert testified that in the event there was a ten-foot error on the reference point at a car traveling 70 miles an hour for a clock of one mile, the error in the resulting reading would be only .133 miles an hour. In the event of a 100-foot error on the reference point at a car traveling 70 miles an hour for a clock of one mile, the error in the resulting reading would be 1.326 miles an hour. The greater the distance used in the clocking of the speeding vehicle, the greater the accuracy obtained.
The instrument has a built in warning device. In the event that the instrument is not properly warmed up or there is insufficient power from the battery source or any other malfunction, the reading obtained will be 00.1 Thus, the operator is alerted to any possible malfunction of the instrument.
For the training for the operation of the Vascar unit it is recommended by the manufacturer that a half-day of classroom work be given to the trainee involving the theory and operation of the Vascar unit, and that the trainee then be given a month to practice in the use of the unit, at the end of which time a test of 30 clockings under different situations is administered. In that test the trainee, in order to be ...