Following too closely, or tailgating, under Vehicle Code 21703 is a frequent reason officers give for a traffic stop, and that stop sometimes turns into a DUI investigation. I am Joel Brand, and here is what the statute actually requires and how it factors into a DUI case.
The text of the law
Vehicle Code 21703. The driver of a motor vehicle shall not follow another vehicle more closely than is reasonable and prudent, having due regard for the speed of such vehicle and the traffic upon, and the condition of, the roadway.
What the statute requires
Section 21703 does not set a fixed following distance in feet or car lengths. Instead it uses a flexible standard: a driver may not follow "more closely than is reasonable and prudent," judged against the speed of traffic, the amount of traffic, and the condition of the roadway. What counts as too close on a wet, crowded freeway at 70 miles per hour is very different from what is reasonable on an empty surface street at 25. A violation is an infraction that adds one point to your record under the DMV point system.
"Reasonable and prudent" is inherently subjective
The entire statute turns on a judgment call. There is no bright-line distance that automatically violates it, which means whether you were following "more closely than is reasonable and prudent" is almost always a matter of opinion. Two officers watching the same gap could honestly disagree. That built-in subjectivity is the defining feature of these cases, and it is also their weakness as a foundation for anything else, because a violation that rests entirely on one officer's estimate of a following distance is rarely as solid as the citation makes it look.
The distance estimate is hard to make and easy to get wrong
An officer claiming a following-too-closely violation is usually estimating, by eye, the gap between two moving vehicles, often from behind or off to the side, sometimes at night. Judging distance and closing speed between two cars from that vantage point is genuinely difficult, and the estimate is frequently unreliable. Traffic conditions also change second to second: another car may have just cut in ahead, briefly shrinking the gap through no fault of the driver behind. Whether a true, sustained violation occurred, as opposed to a momentary and explainable closeness, is often very much in doubt.
Why it matters in a DUI
In a DUI, the following-too-closely observation is usually the officer's stated justification for the stop. If that observation does not actually amount to a violation, for instance because the gap was reasonable for the conditions or another driver created the situation, the basis for the stop is in question. And if the stop was unlawful, the evidence gathered afterward can be suppressed, which is exactly why this small infraction can matter to the whole case.
Challenging the stop
When tailgating is the basis for the stop, I look closely at what the officer actually claims to have seen, how the distance was estimated, and whether it meets the reasonable-and-prudent standard, comparing it to any dash-cam or body-cam video. Where the claimed violation does not hold up, I bring a motion to suppress under Penal Code 1538.5. Suppressing the stop can unravel the DUI, because everything the state has flows from that initial contact.
Following too closely is not impairment
It is worth separating the two ideas. Following another car too closely, even if it was genuinely too close, is not evidence that you were impaired by alcohol or drugs. Sober drivers tailgate constantly, out of impatience, distraction, or simple misjudgment of the gap. Distracted or aggressive driving and impaired driving are different problems with different proof. An officer who saw a short following distance cannot use that to fill gaps in the impairment case. I keep the tailgating allegation in its lane and require the prosecution to prove impairment independently through the chemistry and the field evidence.
When there was a rear-end collision
Following-too-closely citations often arise out of a rear-end collision, which adds a fault dimension on top of the traffic question. Even there, fault for the accident is separate from impairment, and the circumstances frequently complicate the simple picture: the lead car may have braked suddenly or had non-functioning brake lights, or a third vehicle may have forced the sequence. An accident-reconstruction analysis can tell a very different story than the responding officer's first impression. I keep crash fault and alcohol impairment from being conflated, because a driver can be at fault in a rear-end collision and still be entirely sober.
Points, fines, and the record
As a standalone infraction, following too closely carries a fine plus assessments and one point. On its own that is minor, but combined with a DUI it adds to your record and can be addressed as part of the overall resolution. Keeping the point off matters for insurance and for the DMV's negligent-operator thresholds, where accumulating too many points in a set window can trigger a separate license suspension.
How these cases resolve
On its own, a following-too-closely infraction is a minor part of a combined case. The realistic goals are to keep the point off your record, to dismiss the infraction where the distance estimate is unreliable or the conditions explain the gap, and to fold it into the overall resolution of the DUI so it carries no separate consequence. The far more valuable outcome is using a weak following-distance observation to attack the stop itself, because if the stop falls, the DUI often falls with it. As with every part of a DUI, how the tailgating count is handled depends on the strength of the rest of the case, which is why I look at all of it together.
How it fits the larger defense
The following-too-closely issue is one piece of attacking the lawfulness of the stop, the most powerful category of DUI defense. It works alongside challenges to the field sobriety testing and the chemical evidence, and it can reveal broader police mistakes at a DUI stop. See my top DUI defenses and the defenses guide.
Stopped for tailgating and arrested for DUI? Let's talk.
Whether that stop was justified may decide your case, and it is exactly what I review against the video. Use the free case analysis on this page, or call me directly at (888) 271-6644. I answer my own phone, 24/7.
Related traffic-stop charges: misdemeanor hit and run (VC 20002), failure to yield (VC 21801), stop sign violations (VC 22450).