How to beat a speeding ticket by attacking visual estimate of speed

How to Beat a Speeding Ticket – Visual Estimate of Speed

how to beat a speeding ticket

Most Virginia traffic lawyers and Fairfax criminal defense attorneys in Virginia know that in order for a prosecutor to use evidence from the officer’s radar or LIDAR device at trial, they must produce a certificate of calibration. If the certificate contains a legal flaw, then the officer’s visual estimate of speed will be used to try to prove the speed of the defendant.

How can the police prove you were speeding?

Most speeding and reckless driving cases involve the use of one of the following methods to determine speed:

  • LIDAR – laser device
  • RADAR – radar device
  • PACE – “pace” method relies on patrol cruiser speedometer accuracy.

These three methods are discussed in much more detail elsewhere on this site.

As a Fairfax reckless driving lawyer, I have witnessed some criminal and Fairfax traffic lawyers successfully objecting to the admission of a radar or LIDAR calibration certificate, only to fail to properly cross examine the officer regarding visual estimate of speed effectively.  The obvious questions tend to be those involving the officer’s training. But there is a mathematical strategy that tends to be very effective.

How to Fight a Speeding Ticket: Visual Estimate and Why it is Important

If the certificate of calibration is kept out of evidence, visual estimate testimony is the Commonwealth’s back-up, or plan B…it can still be enough to convict the defendant. Therefore, it is key to understand how to also keep out the visual estimate testimony — or at least, call into question the accuracy and reliability of the testimony.

note: calibration certificates are kept out of evidence in various ways. A few ways are explained in detail here. In short, in addition to other requirements: the calibration of the radar or LIDAR must have been conducted within 6-months, and the certificate is an inadmissible copy if it lacks an attestation clause to verify that the the original is in the custody of the lawful custodian of record.

Visual Estimate of Speed Formula

Officers are trained to make a visual estimate of the target vehicle speed. One may wonder why this is necessary, since the police use radar and laser technology. The answer: in order to properly use a radar or LIDAR to catch and charge a driver, the officer must first visually estimate the speed.

How to Beat a Speeding Ticket in Court:
Visual Estimate Formula

S x T = D

Speed x Time = Distance

  • S: actual speed, not alleged speed
  • T: the number of seconds the officer testifies he/she observed defendant.
  • D: distance traveled during visual estimate observation.

Cross Examination Questions to Elicit Numbers to Plug into the Formula

First Line of Questioning: Find out T, or Time

As a Northern Virginia criminal law and Fairfax reckless driving lawyer, when I handle a visual estimate case, I want the officer to testify he or she observed the client for a long period of time.

Here is a hypothetical example of questions:

Q: Officer, you observed my client’s vehicle for enough time to make the visual estimate correct?

A: Yes, I did.

Q: Are you certain…are you absolutely sure it was enough time, and not just a brief 1 or 2 split-seconds?

[most officers will say yes]

Q: Ok, more than 5?

A: At least 3 or 4 seconds, which is sufficient sir.

At this point I would make a note T = 3.5 seconds.

Second Line of Questions: Find Out D, or Distance

The next part of the formula: distance the vehicle traveled during the previously established time frame of visual estimation. Hint: the shorter, the better.

Distance: at Beginning of Visual Estimate

One way a Fairfax reckless driving lawyer may consider establishing distance starts with the distance between the client and the officer upon first visual observation.


Q: Officer, when you initially observed Mr. Smith’s pick-up truck, about how many feet separated you?

The bottom line for this part is to get the law enforcement officer to testify to a number. That number needs to establish how far the driver was from the patrol officer when the officer started the visual estimation.

Distance: Between Officer and Defendant at End of Estimate

The next step is to establish the distance between the driver and officer when the visual estimation was completed. Example:

Q: I take it you had a clear view of my client the whole time, correct?

A: yes

Q: So it wasn’t too far for you given your vision officer, right?

A: no

Q: About how far would you say, officer, was Mr. Smith from you when you concluded your visual estimation?

It is not uncommon for the officer to respond with a variation of “I don’t know.” But if he just testified in response to the prior question about initial distance of observation, it should be no problem to testify to the approximate distance when the observation was complete.

Q: Trooper, you observed Mr. Smith on I-66 Eastbound correct?

Q: How far was my client from you when you first observed him?

A: Hmm, probably around 300 feet I’d say.

Q: When you achieved your visual estimate, how far would you say you were from Mr. Smith?

A: Maybe about 150 feet.

Distance is now established. 300-150= 150 feet.

Going back to the formula: S x T = D

[Reminder: S = rate of travel (speed); T = time observed; D = distance observed]

Hypothetical Example from Our Fairfax Reckless Driving Lawyer:

  • Officer testifies he observed vehicle for between 3 and 4 seconds.
  • We will use 3.5 seconds
  • Thus, T = 3.5
  • Now we have: S x 3.5 = 150

How to take the above formula and solve for S, speed.

Distance (in feet) divided by time (in seconds) equals feet per second.

Thus, 150 feet divided by 3.5 seconds = 42.85 feet per second (fps).

Feet per second must be converted to miles per hour, though, or else everyone (including the judge) will be extremely confused.

1 mph is equal to 1.466 feet per second.

To complete the equation, we divide the feet per second by the 1.466 divisor (1 mph) to arrive at miles per hour.

In the example above, 42.85 feet per second divided by 1.466 feet per second (1 mph) = 29.2 MPH.

To Drive the Point Home: Clear up any Confusion

Q: Trooper Billy Bob, you do know that Mr. Smith, my client, was traveling just 29 mph?

A: No way! He was doing 45!

Q: Maybe I made a miscalculation, I apologize if so, let me re-check my math!

[plug in numbers again but don’t take more than a few seconds or risk looking foolish].

Q: Correct me if I’m wrong, but a few moments ago didn’t you testify under oath that Mr. Smith traveled about 125 feet in the 3.5 seconds you observed his vehicle?

A: Well, yes that is true, I did say that…but it was just an estimate!

Q: Just an estimate, I understand. Isn’t your visual estimate also just an estimate?

A: I guess so

Q: Thank you, Trooper…so Mr. Smith was driving 42.85 feet per second, which is actually just 29.2 MPH.

Note: the officer may comment about the accuracy of the calculation. This should be anticipated.

Q: Wouldn’t you agree, 60 miles per hour is the same as 1 mile per minute?

A: Yes of course.

Q: And you are also aware that there are 5,280 feet in 1 mile, right?

Q: So this means 60 mph is equal to 88 feet per second, does that make sense?

A: I’m not sure, I don’t have a calculator.

Q: No worries, I couldn’t do this kind of math in my head before I practiced, so let me ask you if you would agree with this: there are 60 seconds in 1 minute, right?

Q: and that means in order to find feet per second, only requires dividing feet in a mile (5,280) by 60. And 5280 / 60 is 88 feet per second…do you agree or would you like to see this on a calculator?


Q: if someone traveled at 42 feet per second, it would mean that’s less than 60 mph right?

A: Yes, if what you say is accurate

Q: It is. But it was your testimony that I’m using to get the numbers here, you testified truthfully I assume didn’t you?

A: Yes! But I gave you my estimation.

Q: So my client, according to your testimony, was “speeding” 29.2 mph. Right?

A: No way, I don’t think. He was going faster, I saw it. I was there.

Q: You don’t lie in court, I am quite sure. Am I right?

A: Yes, of course, I never lie in court.

Q: Good, I didn’t think so. If you weren’t lying – and I do believe you – your initial visual estimate on (date of offense) was probably not 100% accurate.

A: Well, I’m no liar, so I guess maybe so.


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Brenton D. Vincenzes is a lifelong Fairfax County resident and Fairfax Criminal Defense Lawyer. He is a member of the Virginia Association of Criminal Defense Lawyers, National College of DUI Defense, NORML, and has been awarded the following in 2014-15: Top 100 Trial Lawyer (National Trial Lawyers) Top 40 Under 40 Trial Lawyer (National Trial Lawyers) Nationally Ranked Top 10 Under 40 Defense Attorney (National Academy of Criminal Defense Attorneys) 10 Best in Client Satisfaction for Criminal Defense (American Institute of Criminal Law Attorneys) Nationally Ranked Top 1% Attorney Award Recipient (National Association of Distinguished Counsel) As a local leader, Mr. Vincenzes mentors troubled youths, volunteers his time to serve at his church, takes select pro bono clients, and strives to improve the community. Mr. Vincenzes represents men, women, and juveniles through zealous and diligent advocacy, strategic planning, and skilled trial work preparation. Mr. Vincenzes' areas of criminal law practice are broad, and include most felonies and misdemeanors such as: reckless driving, DUI & DWI, drug offenses, assault and battery, domestic violence, assault on an officer, destruction of property, alcohol offenses, firearm offenses, larceny, shoplifting, embezzlement, fraud, and other theft offenses, and moving traffic violations among others. His private legal services are available in most Northern Virginia jurisdictions, including Fairfax County, Arlington County, Prince William County, Loudoun County, Stafford County, Alexandria, Manassas, Leesburg, South Riding, and other cities and towns.



  1. I got a speeding ticket a couple weeks ago and I’m trying to fight it in court. I think it’s funny that speeding falls under criminal law. Although I was only going 5 over the speed limit, the cop still gave me a ticket. I know it’s beneficial to know the law and knowing the visual estimate formula will help me for sure in court. Thanks!

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