How to Challenge Radar, LiDAR, and Pacing Speeding Tickets in Wisconsin Courts

Getting pulled over for speeding can be a frustrating experience, especially when you believe you were driving safely. In Wisconsin, law enforcement officers rely heavily on technology like radar and LiDAR (laser), as well as traditional methods like pacing, to catch drivers violating the speed limit. However, these tools are not flawless. Machines can malfunction, weather can distort readings, and human error can lead to inaccurate pacing.

If you want to protect your driving record and keep your insurance rates low, you need to understand the scientific and procedural rules that police must follow under Wisconsin law. You do not have to accept the ticket simply because a machine generated a number. Through our US Lawyer Directory, you can find a local Wisconsin traffic attorney who knows how to dissect these cases and defend your rights in court.

Step-by-Step Process to Fight Speeding Devices in Wisconsin

Whether you are fighting a ticket in Milwaukee, Madison, or Green Bay, the process requires carefully obtaining evidence and understanding the strict standards set by Wisconsin case law and administrative rules. Here is how the process generally unfolds.

Step 1: Plead Not Guilty and Request Discovery

The first step is to enter a 'Not Guilty' plea by the date listed on your Wisconsin Uniform Traffic Citation under Wis. Stat. § 345.11. Once you plead not guilty, your case will be scheduled for a pre-trial conference. This is your opportunity to request 'discovery.' Discovery is the legal process of demanding the evidence the prosecutor has against you. You will need this evidence to see exactly how your speed was measured and what devices were used.

Step 2: Challenge Radar Calibration Logs

If the officer used radar, Wisconsin law requires strict adherence to testing protocols. The landmark precedent State v. Hanson, 85 Wis. 2d 233 (WI Supreme Court 1978) established that for radar evidence to be admissible, the device must have been tested for accuracy both immediately before and immediately after the officer's shift. You or your lawyer should demand the tuning fork test logs and the calibration records for that specific radar unit. If the officer failed to test the device properly, the speed reading might be thrown out of court.

Step 3: Dispute LiDAR (Laser) Weather Interference

LiDAR uses a focused beam of light to measure speed. While highly accurate, it is incredibly sensitive to environmental conditions. Heavy snow, rain, or even thick fog-which are common in Wisconsin winters-can refract the laser beam and produce a false reading. If you were pulled over during a storm in Eau Claire or Wausau, you can argue that weather interference compromised the device. Additionally, the officer must aim the laser at a reflective part of your vehicle (like the license plate); if they aimed at a curved windshield or through traffic, the reading could be invalid.

Step 4: Question Officer Pacing Techniques

Pacing is a technique where the officer follows your vehicle to match your speed using their own patrol car's speedometer. Under Wis. Stat. § 346.57, which governs speed restrictions, speeding must be proven with credible evidence. For pacing to be accurate, the officer must maintain an equal distance behind you for a significant stretch of road (usually at least two-tenths of a mile). If the officer paced you on a winding road, in heavy traffic, or while closing the gap to pull you over, their speed reading is likely inaccurate. You can also subpoena the calibration records for the patrol car's speedometer to prove it was not properly maintained.

How Much Does it Cost in Wisconsin?

Fighting a ticket involves evaluating the costs of the fine versus the cost of defense. Here is a general breakdown:

How Long Does the Process Take?

The timeline for a speeding ticket case depends on the court. Municipal courts, such as the Milwaukee Municipal Court, Milwaukee or the Madison Municipal Court, Madison, typically schedule an initial appearance within 30 to 45 days of the ticket. The pre-trial conference usually happens a month later. If you decide to take the case to a full trial to challenge the radar or LiDAR evidence, the entire process can take 3 to 6 months to resolve.

Frequently Asked Questions (FAQ)