California VC 21658 – Unsafe Lane Weaving and Straddling

Overview of VC 21658

Under California Vehicle Code 21658, it is unlawful for a driver operating a vehicle on a highway or roadway divided into two or more lanes of traffic traveling in the same direction to:

1. Fail to drive within a single lane,
2. Change lanes without reasonable safety or prudence, or
3. Disobey official signs and traffic control devices that direct the flow of traffic.

In simpler terms, VC 21658 prohibits a driver from weaving between lanes or straddling lane dividers in a manner that endangers others on the road.

Prosecution Under VC 21658

Official Signs and Traffic Devices

The California Department of Transportation (DOT) is responsible for the placement of official signs and traffic devices on highways and roadways. Local authorities may also install stop signs or signals within city and county limits, provided they meet DOT standards.

These signs are used to:

• Indicate speed limits and traffic flow,
• Control intersections and crosswalks,
• Regulate lane use and restrictions,
• Warn of school zones, railroad crossings, or construction areas, and
• Manage pedestrian and bicycle safety.

Failure to follow these posted devices can contribute to a violation of VC 21658.

Definition of a Vehicle Under VC 21658

A “vehicle” is defined as any device that enables a person or property to be moved or drawn on a highway. This includes:

• Motor vehicles,
• Motorhomes and trailers,
• Travel trailers and campers,
• Trucks, vans, and passenger cars, and
• Emergency or recreational vehicles.

However, motorized wheelchairs, motorized tricycles, or other mobility devices used by individuals with physical disabilities are not considered vehicles under this section.

Speeding and Unsafe Speed Assessment

Speeding often accompanies a VC 21658 violation. According to California Vehicle Code 22350, unsafe speed determinations are based on engineering standards and radar detection operated by certified officers.

Speeding fines typically include:

• 1–15 MPH over the limit: $238 fine
• 16–25 MPH over the limit: $367 fine
• 25+ MPH over the limit: $490 fine

All officers operating radar guns must undergo 24 hours of POST-certified training and be certified by the California Highway Patrol.

Radar Gun Accuracy and Calibration

To ensure accuracy in issuing citations:

• Officers must complete 54 hours of classroom and field training in radar use.
• Devices must be recalibrated every three years by a state-approved facility.
• At the start and end of each shift, officers are required to perform self-tests on radar and lidar devices to verify accuracy.

If the radar or lidar device was not properly calibrated or the officer was not properly trained, this may be grounds to challenge a VC 21658 citation.

Is VC 21658 a Moving Violation?

Yes. VC 21658 is classified as a moving violation under California law, meaning it can result in points on your driving record and affect your insurance rates. However, some cases may qualify for traffic school to keep the infraction off your record.

Sentencing and Penalties for VC 21658

A violation of California Vehicle Code 21658 can be charged as either an infraction or a misdemeanor, depending on the circumstances.

Infraction Penalties

• Fines up to $1,000
• Eligibility for traffic school to remove points from your driving record

Misdemeanor Penalties

• Up to 6 months in county jail
• Fines up to $1,000
• Possible probation and community service

Examples of VC 21658 Violations

1. A driver is traveling behind a slow-moving car preparing to turn left and decides to straddle the centerline to prevent another car from passing.
2. A driver weaves between lanes on the freeway without signaling or checking blind spots.
3. A driver drifts across lanes while distracted, such as texting or eating while driving.

In each example, the act of unsafe lane movement constitutes a violation, even if no collision occurs.

Defenses to VC 21658 Violations

A skilled Los Angeles traffic defense attorney can challenge a VC 21658 charge using several legal defenses, including:

1. Necessity or Emergency – The driver swerved or changed lanes to avoid an imminent collision, a road hazard, or mechanical failure.
2. Officer Error – The police officer misjudged the driver’s movement or speed.
3. Improper Equipment Calibration – The radar or lidar device used to record speed or lane position was not properly maintained or certified.
4. Lack of Evidence – There is insufficient proof that the driver violated the lane-keeping rules under VC 21658.

Hire a Los Angeles Traffic Defense Lawyer

If you’ve been cited for unsafe lane weaving or lane straddling under California Vehicle Code 21658, you should contact an experienced defense attorney immediately.

Attorney Seppi Esfandi, principal of Esfandi Law Group, has successfully defended countless drivers against traffic and criminal violations across Los Angeles County. His team will carefully review your case, challenge improper evidence, and work to keep your driving record clean.

Call Esfandi Law Group today for a free consultation at (310) 274-6529 and learn how we can help fight your citation.