The door zone
The door zone is the strip of road beside a parked vehicle that a door could swing into when opened. A cyclist who rides inside it may be struck by a door, or may swerve into traffic to avoid one. Being hit by a door can lead to serious injury, and even a near miss can throw a rider off balance, which is why leaving space from parked cars is such a commonly repeated piece of advice.
The width of the zone depends on the vehicle and how far the door opens, and it is often wider than people expect once the door has fully swung out. In general, riding a door’s width or somewhat more away from the side of a parked car is the idea. Because roads and vehicles vary, use your own judgement, and check any guidance from your local authority.
Why this is easy to get wrong
Many roads put the cyclist in a squeeze. Parked cars on one side and moving traffic on the other can make the safer position feel exposed, particularly when drivers behind seem impatient. It is natural to want to tuck in close to parked cars to give others room. But riding in the zone trades one risk for another, and the trade is rarely a good one.
Another issue is that you often cannot tell whether a door is about to open. The driver may not look behind them, a passenger may step out on the road side, or a person may exit a taxi or delivery vehicle without checking.
Scanning for clues
Look at each parked car as you approach and ask whether anyone is inside. Useful clues include:
- Brake lights or reverse lights illuminated.
- A running engine, exhaust smoke, or a recently parked vehicle.
- A figure in the driver’s seat, or movement within.
- A vehicle that has just pulled up, particularly taxis and delivery vans.
- People standing near the kerb, who may be about to get in.
- A shift in the vehicle’s suspension that suggests someone is moving inside.
Look through the rear windows when you can, and keep scanning as you pass, not only as you approach. Be ready to slow down: speed gives you less time to react.
Positioning
If there is room, ride far enough from the parked cars to avoid the opening door. This may mean riding closer to the middle of the lane than feels comfortable at first. A few points apply:
- Move out early and smoothly. Look behind, signal if appropriate, and move gradually rather than swerving at the last moment. Looking behind without drifting is covered in shoulder check.
- Hold a steady line. Weaving in and out of gaps between parked cars sends mixed signals to drivers behind. In many cases it is more predictable to stay out in a consistent line, and the reasoning behind this is described in predictable riding.
- Avoid the gutter squeeze. Riding right next to parked cars may seem to give following drivers more room, but it can invite close passing and leaves you without an escape.
- Use the space you’ve taken with confidence. Positioning is communication. A rider who is clearly and calmly out of the door zone tells drivers where they will be.
Where the road is narrow, vehicles behind may need to wait for a safe point to pass. Taking a sensible position is not rude; it is about safety. At the same time, be courteous: if it is safe and practical to let traffic by at a wider spot, many riders choose to do so. Road positioning more generally is covered in road positioning.
When there is not enough room
Some streets are tight. If there is no room to ride outside the door zone and traffic is heavy, consider these options:
- Slow down so that you have more time to react, and ride as far from the cars as is practical.
- Watch for gaps where you can stop or move out.
- Choose another route when you can, such as a quieter street, as discussed in route planning.
- If it feels too risky, get off and walk for a short stretch, where that is permitted.
None of these removes the risk completely, so treat them as ways to reduce it.
Tips for the passing moment
- Cover your brakes with your fingers as you pass cars you cannot see into.
- Keep your head up and eyes moving between the cars ahead, the mirrors and the traffic behind.
- Look at the mirrors of parked cars, if you can see them, for signs of someone inside.
- Be wary of vehicles that might pull out. A parked car with an indicator on or wheels turned may be about to move. Anticipating other road users is a skill in itself, described in anticipating road users.
- Keep your speed modest where you cannot see inside vehicles.
Rules differ
Road rules about where cyclists should ride, how drivers should pass, and who has priority differ by country and sometimes by town. Check your local rules. Wherever you ride, a helmet, good lights if visibility is poor, and a calm, consistent approach all help.
Practise the positioning on a quiet street with few cars first. Building the habit of looking, deciding early and holding a clear line makes busy streets feel more manageable over time.