siktlinje

Siktlinje, meaning line of sight, is a concept used in road design, urban planning, and safety assessments to describe the unobstructed visual path between an observer and a target of interest along a route or at a location. The siktlinje represents what a road user can see from a given vantage point, typically with regard to other vehicles, pedestrians, traffic signs, or potential hazards.

In practice, siktlinje is applied in contexts such as road and intersection design, driveway visibility, pedestrian crossings, railway crossings, municipal streetscapes, and site planning around buildings or vegetation. It helps determine whether important cues, such as oncoming traffic or a stop line, are visible early enough to respond safely. The concept is paired with the related notion of sight distance, which quantifies the distance a user can see clearly in order to perceive and react to hazards.

Assessment and measurement of siktlinje depend on several factors. The observer’s eye height, the height of the target, the geometry of the site (straight or curved alignments), and the presence of obstacles all influence visibility. The required siktlinje is not fixed; it is typically defined in national or regional standards and is linked to design speeds, stopping distances, reaction times, and safety criteria. Weather, lighting, and glare can temporarily reduce effective sight lines.

Common issues that reduce siktlinje include tall vegetation, parked vehicles, architectural features, terrain changes, and misaligned sightlines at intersections. Remedies include trimming or removing obstructions, regrading, adjusting landscaping, relocating signs, and redesigning curves or approaches to restore adequate visibility.