The majority of speeding tickets are issued using radar or laser. Police radar units were developed using the same technology as Doppler radar, which is used in predicting and demonstrating weather patterns. Simply put, radar works by recognizing the motion of large bodies. In meteorology, radar identifies clouds and weather systems. For traffic patrol, the radar units are supposed to identify motor vehicles. While radar is fairly accurate assuming certain conditions, this is not so in every situation.
Because radar is designed to recognize the largest moving body passing before the unit, it is not ideal for use in congested areas of traffic. Why? A simple explanation will illustrate how radar units can become inaccurate in traffic. Assume a smaller model vehicle, such as a Honda Civic, and a larger model vehicle, such as a Ford F-150, are traveling along an interstate in the same direction. The Honda is in the lane closest to the shoulder of the road, while the F-150 is in the left lane. An officer using a radar unit is located to the right on the shoulder of the interstate. If the Honda and the F-150 are approaching the officer, the radar unit will more than likely recognize the F-150 over the Honda. Unfortunately, the Honda may suffer the fall for the F-150. It is difficult for the officer to discern which vehicle was actually speeding unless it is blatantly visually apparent. It is easier, however, to pull over the vehicle traveling in the lane closest to the shoulder due to proximity.
An additional flaw to radar units is that, as with all scientific equipment, radar units require certain maintenance to ensure accuracy. Most, if not all, states have laws requiring the local police departments to have the radar units independently inspected, calibrated and certified on an annual basis. As part of this maintenance, the police departments are further required to maintain records of the regular maintenance.
However, as with all scientific equipment, radar units, including those used by police officers, require certain maintenance to ensure accuracy. Many states have rules requiring the local police departments to have the radar units sent to an independent laboratory for inspection, calibration, and certification. Do police departments actually adhere to these requirements? Possibly...but more often, not.
How can you use this information to beat a speeding ticket? Request the serial numbers for each radar unit the police department owns and also request the maintenance records for the radar units in the last year or two. Requesting this information will lessen the opportunity for the police department to cover the lack of maintenance by presenting maintenance records for another radar unit that was not used in issuing your speeding ticket.
Is there any guaranteed way to fight a speeding ticket successfully? Unfortunately, no. However, armed with the knowledge of how radar units operate and the pitfalls of the technology, you stand a far better chance of success than simply making an exclamation in court.