A Car Door Opened Into Your Lane. Colorado Law Puts That on the Person Who Opened It.
Dooring occupies a strange position among bicycle crashes. It happens at effectively zero speed on the driver’s side, so it does not look serious to anyone who was not on the bike. Nothing was moving. There was no impact between vehicles. The car may not have a scratch on it.
The rider, meanwhile, went over the bars into pavement at fifteen miles an hour, or swerved left into a travel lane and got hit by whatever was coming. Fractured collarbones, broken wrists, facial injuries, road rash requiring debridement, and head injuries are the routine outcomes. It is one of the few crash types where the property damage tells you almost nothing about the human damage.
Colorado Has a Statute That Says This Directly
Some states leave dooring to general negligence principles. Colorado does not. C.R.S. 42-4-1207 provides that no person shall open the door of a motor vehicle on the side available to moving traffic unless and until it is reasonably safe to do so and can be done without interfering with the movement of other traffic, and that no person shall leave such a door open longer than necessary to load or unload passengers. A violation is a class B traffic infraction.
Three features of that language matter after a crash. The duty attaches to the person opening the door, whether that is the driver or a passenger. It is written as a precondition rather than a caution, meaning the door may not be opened until it is safe. And the second clause covers the door left standing open, which is the scenario in a surprising share of these collisions.
Negligence Per Se Is Powerful, Not Automatic
You will see it written that violating the statute makes the door opener automatically at fault. That overstates it in a way worth correcting, because it sets up false expectations.
What a safety statute violation does is establish the duty and the breach as a matter of law, which removes the argument about whether the conduct was unreasonable. That is a substantial advantage. It does not eliminate causation, and it does not eliminate comparative fault. A defendant can still argue that the rider was riding without lights at night, was traveling at an unreasonable speed for a corridor lined with parked cars, or was riding against traffic. Those arguments go to the rider’s percentage, and in Colorado a rider found 50 percent or more responsible recovers nothing.
So negligence per se moves you a long way down the field. It does not put the ball in the end zone. Understanding the difference is what keeps a strong case from being handled casually.
How the Rider’s Percentage Gets Argued
Because comparative fault does the real work in these cases, it is worth knowing how the allocation operates. Under C.R.S. 13-21-111, a rider’s recovery is reduced in proportion to their share of the fault, and recovery disappears entirely if that share reaches 50 percent.
So the defense strategy in a dooring case is rarely to deny the door opened unsafely. That is usually indefensible. The strategy is to build the rider’s percentage through a series of small assertions: no headlight or reflectors at dusk, speed that was reasonable on an open road but arguably not alongside parked cars, headphones, or a claim that the rider had time to stop. Each assertion is worth percentage points, and percentage points are worth money.
Answering them requires the same specificity used against them. What the lighting conditions actually were. What equipment the bicycle carried. What sight distance existed between the door and the point of impact, which is frequently a matter of a few feet and a fraction of a second.
The Door Zone Is a Real Design Problem
Wherever parallel parking sits alongside a bike lane, there is a strip of roughly three to four feet where an opening door will reach a rider. Many bike lanes in Colorado are striped partly or wholly inside that zone, which puts a cyclist following the paint exactly where the hazard is.
This produces a maddening argument. A rider positioned outside the door zone, further into the travel lane, gets accused of failing to ride as far right as practicable. A rider positioned inside the lane as striped gets doored. Colorado law permits cyclists to leave the right portion of the roadway to avoid hazards, including opening doors and other conditions that make riding at the edge unsafe, and it permits taking the lane where it is too narrow to share safely. A rider who moved left to stay clear of parked cars was doing something the law contemplates, not something reckless.
Our page on dooring accidents in Colorado covers how positioning disputes typically get resolved.
The Second Collision
The most severe dooring cases frequently involve two impacts. The rider strikes the door or swerves to avoid it, then goes into an adjacent travel lane and is struck by a passing vehicle. Occasionally the door is missed entirely and the entire injury comes from the second collision.
That sequence raises a genuine legal question about who is responsible for what. The door opener will argue that the passing motorist caused the injury. The passing motorist will argue they had no opportunity to react to a cyclist who appeared without warning. Colorado law allocates fault by percentage among all responsible parties, and the answer is usually that both bear some share.
The practical significance is about insurance. Two responsible parties means potentially two policies, which in a case with serious injuries can be the difference between a recovery that covers the harm and one that does not. This is also the scenario where a rider’s own uninsured and underinsured motorist coverage frequently becomes relevant, because cyclists are typically covered by their own auto policy while riding.
Evidence That Decides These Cases
The physical evidence is unusually informative. Where the door contacted the bicycle, and where the bicycle contacted the door, tells you a great deal about the geometry. The final resting position of the bike relative to the parked car establishes approximate speed and angle. Damage to the door edge, sometimes dismissed as trivial, is corroboration.
Photograph the parked vehicle in position before it is moved, including the open door if it is still open, and photograph the lane striping and the distance from the parked car to the lane line. Measure it if you can. In urban and downtown corridors, nearby business cameras frequently capture the entire sequence, and that footage is typically overwritten within days.
Identify the person who opened the door, not just the registered owner, because the passenger who opened a rear door on the traffic side is the one who breached the duty and coverage questions can turn on which it was. And get the names of witnesses, because dooring is often observed by people on the sidewalk who will otherwise simply walk away.
What to Do at the Scene and After
Call law enforcement even though the damage looks minor, because a report documents the statutory violation and creates a contemporaneous record. Accept medical evaluation rather than declining it, because adrenaline reliably masks fractures and head injuries in the first hour and a same-day record is what defeats the argument that the injuries came from somewhere else.
Preserve the bicycle and do not repair it, since the frame, wheel, and component damage are evidence. Keep the helmet even if it looks intact, because a cracked or compressed helmet is significant proof of a head impact. Photograph your injuries as they develop, since road rash and bruising often look worse on day three than at the scene. And do not give a recorded statement to the driver’s insurer before you have talked to a lawyer.
Whose Insurance Actually Pays
Coverage in dooring cases is less obvious than it looks, and it is worth sorting out early.
The parked vehicle’s auto liability policy is the usual first source, since the door is part of the vehicle and the person who opened it was occupying it. Where a passenger opened the door, that passenger may also have coverage under their own policy, which can matter when the vehicle’s limits are inadequate. If a second vehicle struck the rider after the initial contact, that driver’s policy is in play as well.
Your own auto policy is frequently relevant even though you were on a bicycle. Medical payments coverage typically follows you as a pedestrian or cyclist and pays treatment costs regardless of fault. Uninsured and underinsured motorist coverage generally responds when the at-fault party has no insurance or not enough, which comes up more often than people expect given how severe these injuries can be relative to the modest limits many drivers carry.
Talk to a Colorado Injury Lawyer
Rampart Injury Lawyers represents injured cyclists in Castle Rock, Douglas County, and along the I-25 corridor from Greenwood Village to Colorado Springs. Todd Travis and Jordan Travis handle bicycle cases where a carrier is treating a low speed crash as a low value claim despite fractures, surgery, and a head injury. If a car door put you on the pavement, contact our office for a free consultation with an attorney.
