Virginia Speeding Ticket Defenses
Most people who received a Virginia speeding ticket think there is no way to beat the case in court. Courts who hear evidence on Virginia speeding tickets rely primarily on two things: the testimony of the officer, and the reliability of the radar used to measure your speed. Radar is the most most common type of speed measuring device used by police, but they also use LiDAR in certain locations across Virginia.
LiDAR versus Radar
Radar uses sound waves to detect your speed. The radar unit sends out a sound wave that is silent to the human ear. When that sound wave strikes your vehicle it reflects the wave back to the radar unit. The unit then measures how fast the reflected wave is sent back to the unit – called the doppler shift. By measuring the doppler shift the radar unit measures your speed.
LiDAR uses light waves that are invisible to the human eye, much in the same way as radar uses sound waves. And, much like radar, it measures the time it takes for a wave to be sent out and reflected back to the LiDAR unit. The biggest difference between LiDAR and radar is the accuracy. Light waves travel much faster than sound waves. (984,000,000 feet per second versus 1,000 feet per second.) So, LiDAR units can measure your vehicle speed 1,000 times in just one second.
The other big difference between LiDAR and radar is the “target cone.” Both radar waves and light waves increase in the shape of a cone as they leave the measuring unit. For radar, this cone can be very, very large. This is why it can sometimes be difficult for officers to tell whether it is your vehicle they were measuring, or whether there is another vehicle in the distance that is producing the results. This is one of the major reasons that officers are generally required to estimate your speed, and then use the radar to verify their estimate.
The LiDAR cone is very small. At 1,000 feet the cone will generally be 3 feet in diameter. This makes targeting a specific vehicle much easier than with a radar unit, and gives the officer added confidence in his measurement of your speed. This does not, however, mean that LiDAR units are infallible.
Defenses to LiDAR tickets
There are several defenses to Virginia speeding tickets issued based on LiDAR evidence. The more common ones include:
- Improper machine calibration;
- Improper or incomplete training and certification records of the officer using the machine;
- LiDAR beam was sent from inside the police vehicle with the windows up;
- LiDAR unit was perpendicular to your vehicle when the measurement occurred;
- LiDAR “sweep error”;
- Many others.
If you have received a Virginia speeding ticket, contact our office to learn how we can help you avoid higher insurance costs, and other penalties. Our consultations are free, and if we do not try the case, you often do not even have to appear in court. If you have any questions about this posting, go to our Facebook page and ask us in the comment section.