Good visibility in intersections is crucial for correct decisions about speed, positioning and right of way. By understanding the concepts of stopping sight and clear zones, you can better assess risk and avoid misjudgments.
Concepts
| Concept | Explanation | Practical significance |
|---|---|---|
| Stopping sight | Sight distance needed to stop safely | Stop if you cannot see far enough ahead |
| Clear sight | The area you must be able to see into to assess crossing traffic | Move your gaze and position to open up visibility |
Practical method at intersections with limited visibility
- Reduce speed early and move your gaze toward conflict points
- Make a clear rolling observation stop before the sight line
- Creep forward in small steps to increase clear sight without hindering others
- Confirm with gaze and shoulder check before driving in
For systematic positioning and position, see Positioning and driving technique. For assessment of speed and margins, see Speed and distance.
Typical sight obstructions
| Obstruction | Consequence | Action |
|---|---|---|
| Parked cars, snow or vegetation | Hides crossing traffic | Creep forward, increase observation angle |
| Hill crest before intersection | Reduced stopping sight | Reduce speed earlier |
| Sharp angles in T-intersections | Narrow zone for clear sight | Angle the car slightly to open up visibility |
Common errors and solutions
| Error | Consequence | Correct practice |
|---|---|---|
| Driving in without confirmed clear sight | Side collision | Creep forward step by step and confirm with gaze |
| Stopping too far behind sight line | Unnecessarily long waiting time | Roll forward to effective observation point |
| Too high speed toward intersection | Too late decision | Reduce speed early, use low gear/engine braking |
Stopping sight and speed
The stopping sight must always be at least as long as your calculated stopping distance. See detailed formulas in Reaction time and braking distance.
| Speed | Typical reaction distance (1.0 s) | Approximate braking distance on dry surface | Recommended assessment |
|---|---|---|---|
| 30 km/h | 8 m | 6–9 m | Require clear visibility before entering |
| 50 km/h | 14 m | 20–25 m | Reduce speed early when obstructed |
| 70 km/h | 19 m | 40–50 m | Plan to stop before sight line |
When sight lines are limited by weather, darkness or obstructions, adjust light use and speed choices. See Use of lights and signals.