Common Mistakes Drivers Make During Field Sobriety Tests

Field sobriety tests are commonly used during DUI investigations to help police officers determine whether a driver may be impaired by alcohol or drugs. These roadside tests may appear simple, but many drivers make mistakes during the process without realizing it.

Stress, confusion, medical conditions, and poor roadside conditions can all affect performance during a DUI stop.

Many people also ask, Are Field Sobriety Tests Accurate, especially when sober drivers sometimes struggle with the tests. While these evaluations are widely used in DUI investigations, they are not perfect and can be influenced by several outside factors.

Understanding the most common mistakes drivers make during field sobriety tests can help individuals better understand how DUI investigations work and why roadside testing results are sometimes challenged in court.

What Are Field Sobriety Tests?

Field sobriety tests are physical and mental exercises used by law enforcement officers during DUI stops. The purpose of these tests is to evaluate a driver’s:

• Balance

• Coordination

• Ability to follow instructions

• Divided attention skills

Police officers often use these tests after observing signs of impaired driving, such as:

• Swerving

• Speeding

• Running traffic signals

• Delayed reactions

• Erratic driving behavior

The National Highway Traffic Safety Administration (NHTSA) recognizes three standardized field sobriety tests commonly used during DUI investigations.

Walk-and-Turn Test

The driver must walk heel-to-toe in a straight line, turn around, and return the same way while following detailed instructions.

One-Leg Stand Test

The driver must stand on one leg and count aloud for a specified period.

Horizontal Gaze Nystagmus Test

The officer checks the driver’s eyes for involuntary jerking movements while the driver follows an object with their eyes.

Although these tests are designed to help identify impairment, they do not directly measure Blood Alcohol Concentration (BAC). Instead, they rely heavily on officer observation and interpretation.

Not Listening Carefully to Instructions

One of the most common mistakes drivers make during field sobriety tests is failing to listen carefully to the officer’s instructions.

During a DUI stop, many drivers feel nervous, overwhelmed, or distracted by:

• Flashing police lights

• Passing traffic

• Anxiety about the situation

• Loud roadside environments

Because of this stress, drivers may misunderstand directions or forget specific steps during the test.

For example, during the walk-and-turn test, officers often give multiple instructions at once,

including:

• Where to place feet

• When to start walking

• How many steps to take

• How to turn properly

Missing even one instruction may be viewed as a sign of impairment.

Starting the Test Too Early

Another common mistake is beginning the test before the officer says to start.

Officers usually explain and demonstrate the test first. However, anxious drivers sometimes start walking or balancing too early. This is especially common during the walk-and-turn test.

Starting early may count against the driver because officers often interpret it as:

• Inability to follow directions

• Lack of focus

• Impaired judgment

Even sober individuals may accidentally make this mistake due to nervousness.

Talking Too Much During the DUI Stop

Many drivers become extremely nervous during roadside investigations and begin talking excessively.

Drivers may:

• Apologize repeatedly

• Volunteer unnecessary information

• Admit to drinking

• Try to explain their behavior

While remaining polite is important, excessive talking can unintentionally provide officers with additional evidence during a DUI investigation.

Statements made during the stop may later appear in:

• Police reports

• Court testimony

• DUI evidence

Staying calm and speaking carefully is generally recommended during any law enforcement interaction.

Losing Balance Because of Anxiety

Field sobriety tests often take place under stressful conditions. Even sober drivers can struggle with balance and coordination during roadside testing.

Common environmental factors include:

• Flashing emergency lights

• Heavy traffic

• Uneven pavement

• Cold weather

• Wind

• Late-night fatigue

Anxiety itself can also affect physical coordination. Some drivers shake, stumble, or lose

focus simply because they are nervous.

This is one reason field sobriety tests remain controversial in some DUI cases.

Wearing Improper Footwear

Footwear can significantly affect performance during roadside sobriety tests.

High heels, work boots, sandals, slippery shoes, or uncomfortable footwear may make balancing difficult during:

• The one-leg stand test

• The walk-and-turn test

Drivers who are not dressed for physical activity may struggle even when fully sober.

Some officers allow drivers to remove certain shoes before testing, but not always. Poor footwear conditions can sometimes become part of a DUI defense argument later in court.

Performing Tests on Uneven Surfaces

Field sobriety tests are not always conducted under ideal conditions. Officers may ask

drivers to perform tests on:

• Gravel roads

• Wet pavement

• Sloped shoulders

• Uneven sidewalks

• Poorly lit areas

These conditions can make balancing difficult for anyone.

Uneven surfaces may affect:

• Walking stability

• Turning ability

• Coordination

• Confidence during testing

Roadside conditions are important because improper testing environments may reduce the reliability of the results.

Failing to Mention Medical Conditions

Many drivers forget to tell officers about medical conditions or injuries that may affect test performance.

Several health issues can interfere with balance, coordination, or eye movement, including:

• Back injuries

• Knee pain

• Inner ear disorders

• Neurological conditions

• Arthritis

• Vertigo

• Anxiety disorders

For example, someone with a previous leg injury may struggle with the one-leg stand test even without alcohol impairment.

Drivers who fail to mention these conditions may later face difficulty explaining poor performance during court proceedings.

Assuming the Tests Are Easy

Some drivers underestimate how difficult standardized field sobriety tests can be.

These tests are designed to challenge a person’s ability to:

• Follow instructions

• Divide attention

• Maintain balance

• Concentrate under pressure

Even healthy and sober individuals may have trouble performing perfectly.

For example, the walk-and-turn test requires drivers to:

• Listen carefully

• Count steps

• Balance heel-to-toe

• Turn correctly

• Avoid using arms for balance

Trying to complete all these tasks under stress can be challenging.

Trying to Rush Through the Test

Drivers often attempt to finish the tests quickly because they feel uncomfortable or embarrassed.

Rushing can lead to:

• Missed instructions

• Incorrect turns

• Loss of balance

• Counting mistakes

• Poor coordination

Field sobriety tests require controlled and deliberate movements. Moving too quickly may create the appearance of impairment even when alcohol is not involved.

Remaining calm and focused is important during roadside testing.

Arguing With the Officer

Another common mistake is becoming argumentative or confrontational during the DUI investigation.

Drivers may become frustrated because they believe the stop is unfair or because they are nervous about the situation. However, arguing with officers can:

• Escalate the encounter

• Increase tension

• Make communication more difficult

Remaining respectful and cooperative is usually the safest approach during any traffic stop.

Common Police Errors During Field Sobriety Tests

Drivers are not the only ones who make mistakes during field sobriety testing. Police officers can also make errors that affect test reliability.

Common officer mistakes may include:

• Giving unclear instructions

• Failing to demonstrate the tests properly

• Conducting tests on unsafe surfaces

• Improperly scoring the tests

• Ignoring medical conditions

• Rushing evaluations

Because field sobriety tests depend heavily on officer observation, proper training and standardized procedures are extremely important.

Can You Refuse a Field Sobriety Test in Colorado?

In Colorado, field sobriety tests are generally voluntary. Drivers are not usually legally required to perform roadside balance and coordination tests.

However, refusing field sobriety tests does not automatically prevent arrest. Officers may still rely on:

• Driving behavior

• Physical observations

• Statements made during the stop

• Other evidence

It is important to understand that field sobriety tests differ from evidentiary breath or blood tests required under Colorado’s Express Consent Law after a DUI arrest.

How DUI Lawyers Challenge Field Sobriety Test Results

DUI defense attorneys often challenge field sobriety test results because these tests can be subjective and influenced by many outside factors.

Attorneys may review:

• Officer body camera footage

• Roadside conditions

• Medical limitations

• Officer training records

• Test administration procedures

A DUI lawyer may argue that poor test conditions or physical limitations affected the driver’s performance rather than alcohol impairment.

Final Thoughts

Field sobriety tests are a common part of DUI investigations, but many drivers unintentionally make mistakes during roadside testing. Nervousness, poor weather, medical conditions, uneven surfaces, and confusion can all affect performance, even for sober individuals.

Understanding the most common mistakes drivers make during field sobriety tests can help people better understand how DUI investigations work and why these tests are sometimes challenged in court. Because field sobriety testing is not always perfect, drivers facing DUI allegations should understand their legal rights and consider seeking professional legal guidance when necessary.