Pre-Operational

Before operating a lidar, the officer or operator should first check to make sure each component is with/on the device, as well as in place. The operator should then inspect the device for external damage, missing components, or any damage that could prevent the lidar from functioning accurately and properly. 

Additionally, the operator must carry out accuracy tests prior to using the device in the field. This includes:

• Internal accuracy check – Light segment and indicators test. The lidar operator performs a light test to ensure all light segments and indicators are functioning properly.  
• Internal circuit check 
• External accuracy check – alignment
• Range accuracy

If there is any issue that could harm permanence, the lidar needs to be immediately removed from operation in the field, and repaired before returning.

Field Operation

Once the pre-operational checks have been made, the lidar device should be transported in the officer’s vehicle. There should be some sort of holster to keep the device in place when the vehicle is in motion, or another method to keep it in place. This method should not obstruct the vision of the officer while driving, limit his or her movement in or exiting the vehicle, and should allow for the device to be easily accessed. 

The device should also be secure enough that injury would not occur from the device in the instance of a crash, or driving in pursuit. It should never be placed in the driver’s lap, in the passenger seat, or anywhere other than the saddle bags in the case of motorcycle use. 

The operator also must develop a tracking history when attempting to use the lidar as a viable piece of evidence in the Vermont court of law. There are several aspects to tracking history, such as:

• Visual observation – The officer must identify the target, estimate its speed, estimate the distance to the target, and observe the environment.
• Audio confirmation – The officer must listen to the pitch of the audio from the lidar and make sure it is giving off a target acquisition tone. 
• Unit confirmation – The lidar must give off steady or multiple readouts that are consistent, and match with a relative degree of similarity, the officers estimation. 

Factors Affecting Lidar Operations

1. Radio Frequency Interference (RFI) – One way this occurs is through the transmitters of law enforcement radios, walkie-talkies, or business radios. To avoid this, abstain from transmitting radio signals in or around the vehicle while trying to take lidar readings. Another variable that can cause frequency interference is light devices. Certain equipment used for lighting such as mercury vapor, neon, or fluorescent lights can cause interference and the officer should avoid taking readings around these lights. A third variable is electrical lines, which can also cause interference, and the officer should choose a site to operate in that is free from this kind of interference. 
2. Panning – when the laser is swung quickly past a stationary object, causing an error reading.
3. Sweep effect – If the operator is striking the target vehicle with the laser from an angle, he or she may strike the back first and then the front, or vice versa. This creates an inaccurate reading, either faster or slower depending on which part of the vehicle was struck first. The officer needs to make sure they maintain a steady aiming point on the target. 
4. Windshield obstruction – The windshield can limit the range of the device, but will not limit the accuracy. 
5. Weather – Weather conditions such as rain, smoke, fog, and dust clouds can limit the range of the lidar. 
6. Low Voltage – If the operator experiences a low voltage incident with the device it should be removed from the field, as this can create unreliable and inaccurate readings. 
7. Cosine Effect – The larger the angle the lidar is being operated from in comparison to the target vehicle, the lower the speed reading is in comparison to reality. This always works in the motorists favor. For instance someone who is traveling at 70 miles per hour would be perceived to be traveling at 65.78 miles per hour from a 20 degree angle. 

Legal Considerations

Lidar is used by law enforcement in Vermont as a form of evidence at Judicial Bureau hearings. For this evidence to be admissible in court, there must be sufficient reason to believe that the lidar reading was an accurate representation of the speed of the target vehicle, at the time of the alleged violation. Therefore the basic accuracy questions must be asked. Do we know that the operating principles of the lidar were valid? Was it working properly at the time of the alleged violation? Did the operator have the proper qualifications and perform properly? Do we know that the vehicle accused was the vehicle that the reading came from?

It is important to understand how lidar devices are used in the field properly, so that you can challenge the validity of the reading if you believe it was wrong, or you believe the officer was not operating the device properly. Do not allow an allegation backed by false operation to harm your driving record, or cost you money. All speeding tickets are viable to be challenged, and challenging the accuracy of the lidar as well as how it was operated/tested on the day of the allegation is an effective way to clear yourself of any charges or fines. 

History

In 1960, Theodore H. Maiman announced the build of a red coherent light pushed from a ruby crystal, which was the first laser. Nearly 30 years later in 1989, the first law enforcement speed measurement laser device was patented. 

Lidar & Laser

Lidar is an acronym. It stands for “light detection and ranging.” Laser is also an acronym, standing for “light amplification by Stimulated Emission of Radiation. Lidar devices are designed to measure speed through energy produced through a laser device. The term lidar is used when describing a device used for down the road speed measurement, currently only designed for stationary use. 

The Science

The technology behind the laser is fairly complicated. When put in its most simple form, laser energy is created by energizing a lassing medium, a piece of active material, which has been placed in a sandwich between mirrors. 

The atoms of the medium are placed into an excited state from an outside energy source. They store some of this energy, which allows them to release some of their already stored energy. This releases as light energy, resulting in amplification of incoming light. 

The two mirrors are placed at an exact distance apart from one another. This creates a standing wave bouncing back and forth from one mirror to the other. This allows the light waves to become lined up with one another. One of the mirrors is designed to allow some of this light to escape, and pass through as a laser beam. 

Lasers can be produced from several different active materials. Some examples of different types of lasers include the semiconductor, gas, chemical, excimer, and free electron. There are also many different types of optical resonator devices. Some of the typical ones include:

• Semi-Conductor Lasers – unlimited uses in high technology applications such as fiber optics and laser devices
• Gas Lasers – popular applications include the entertainment industry, light shows and movies.
• Chemical Lasers – used for internal confinement and military applications
• Excimer Laser – used in the medical field for surgical procedures
• Free Electron Laser – develop powerful light sources for defense, industry and research

How Does it Work?

The lidar employs a “time of flight” method to measure the speed of the desired vehicle. It does this by shooting out a short burst of lasers at the vehicle, all measuring the range of the vehicle from the lidar. The device then adds these measurements together, seeing how fast the vehicle was either getting closer or moving further away, calculating speed. Think of this as a basic math problem in high school: speed = distance/time. If the driver is moving away from the operator it presents the speed value as a negative, and if the driver is moving towards the operator it is presented as a positive value. 

The lidar carries three distinguishable characteristics similar to those of other forms of electromagnetic energy. These are:

• Signal speed – Lidar lasers travel at the speed of light, which is generally accepted to be 186,282 miles per second. 
• Wavelength – “The distance between two points in a periodic wave that have the same phase.” The wavelength of a lidar is about 904-905 nanometers.
• Frequency – A measurement of cycles per second. The frequency of lidar is about 330 terahertz.

Lidar also carries the same behaviors as other forms of electromagnetic energy, meaning that it can be reflected, refracted, or absorbed. 

It is important to understand how lidar works, and understand your rights that go along with it. Do not allow a false allegation to harm your driving record, cost you money, or even place you in prison. Speeding violations are all viable to be taken to court in Vermont at the discretion of the alleged violator, who stands to gain from having the punishment reduced or revoked and challenging the accuracy of the Lidar is one such strategy to attack the validity of the State’s case.

A Look Into Violations That Can Cause Loss of Your CDL (Commercial Driver’s License)

Many actions taken by those who have their CDL, or trucking license, whether it be behind the wheel of a commercial motor vehicle (CMV) or personal vehicle, can result in the suspension or loss of licensure. This can lead to loss of income due to a temporary inability to work, or even a need to find a new career.

Alcohol, Felonies, Abandoning an Accident

In contrast to the typical blood alcohol limit of .08%, it is illegal to operate a CMV at .04% or more. Operating a CMV implies consent to be tested for alcohol in the system. You will lose your CDL for at least one year for driving a CMV under the influence of alcohol, refusing blood alcohol testing, driving under the influence of a controlled substance, leaving the scene of an accident, committing a felony involving the vehicle, or causing a fatality due to negligent operation. This is upped to at least three years if the CMV being driven is denoted as having hazardous materials. You will lose your license for life on a second offense, or using your CMV to commit a felony involving controlled substances.

Serious Traffic Violations

Serious traffic violations include speeding (15 or more over the posted limit), reckless driving, reckless lane changes, following vehicles too closely, traffic offenses while driving a CMV that are related to a fatality, as well as driving without CDL or operating a CMV without the correct CDL class. Committing any of these violations twice, in a three year span, will result in you losing your CDL for 60 days, and 120 days for committing three violations in that 120 day span.

Violation of Out of Service Order

If a driver is placed on an out of service order, they must not operate a CMV during the time under which they are ordered out of service. One of the reasons a driver could be placed out of service is for having alcohol in their system, but below .04%. Violations of this order come with a 90 day CDL suspension for the operator’s first violation, a year suspension for two violations in a ten year span, and three year suspension for three or more violations in a ten year span.

Railroad-Highway Grade Crossing Violations

Railroad-Highway violations occur when the operator does not comply with federal, state, or local regulations pertaining to one of six offenses at a railroad-highway grade crossing. These include: failing to stop at unclear tracks for drivers not required to stop, failing to slow down to check that tracks are clear for those who do not have to stop, failing to stop for those required, driving through tracks without having enough space to make it through without stopping, failing to obey traffic control devices at the crossing, and failing to negotiate a crossing because of a lack of undercarriage clearance. The first violation of these rules results in a 60 day license suspension, 120 days for a second offense in three years, and a year for three or more violations in a three year span.

Traffic Violations in Your Personal Vehicle

CDL holders may also lose their license for violations of the law with their personal vehicle. If your ability to operate your personal vehicle is revoked, canceled or suspended for any reason other than parking violations, you also lose CDL privileges. If the loss of license is due to alcohol, controlled substance, or felony violations, you will lose your CDL for a year from the first offense, and life for the second.

Know Your Rights

As a commercial driver’s license holder, it is important to know your rights, when it comes to CDL traffic violations and those violations involving your personal motor vehicle. Do not let an allegation become a permanent blemish on your ability to provide for yourself and your family. You have a right to an evidentiary hearing on all allegations and should pursue any remedy possible to either eliminate or mitigate your risk for long term effects.