VI.3Rail traffic

VI.3.1 Protected interest and typical glare situations

The observer is the train driver. The viewing direction follows the track; the driver must reliably recognise the line and the aspects of semaphore and light signals. A reflection can dazzle the driver like a road user (Ch. VI.2) and can additionally outshine a signal if it comes from the same direction as the signal.

Situations in which disturbing glare can occur:

• lines running parallel or at an angle to a system, with a low sun in the direction of travel,
• signals that appear in front of a PV area as seen by the train driver,
• level crossings, where road traffic is affected as well,
• stations and stops with signals close to roof or façade systems.

VI.3.2 Guidelines at a glance

The sources evaluated contain no requirements of railway infrastructure companies. RVS 05.06.11 only regulates information and advertising signs near level crossings (section 4.6, p. 12), not PV systems.

VI.3.3 Position paper of the Federal Highway Authority (by analogy)

The position paper applies to federal trunk roads (ch. 1, p. 3) and does not mention railways. Its criteria describe the glare of a vehicle driver looking in the direction of travel and can therefore be transferred to train drivers by analogy:

• relevant field of view ±30° around the main viewing direction, central visual area ±10° (ch. 3, p. 5),
• exclusion criteria luminance ≤ 30,000 cd/m², vertical size ≤ 0.30° outside ±10°, sun overlap at sun elevation ≤ 5° (ch. 3, p. 6),
• calculation for the whole year at a resolution of at most 5 min, module-typical reflection with beam spread (ch. 4, pp. 6–7).

Details are given in Ch. VI.2, section VI.2.3. The justification of sun overlap via the sun visor in the vehicle does not transfer if the train has no comparable visor.

VI.3.4 OVE R 11-3, section 6.2.2 (Austria)

In rail vehicle traffic, glare is not permitted (section 6.2.2, p. 12):

• at signals (semaphore and light signals) for rail traffic,
• at level crossings according to ÖBB-DV V2.

The recognisability of signal aspects at stations and stops must not be affected either by incident light from reflections or by reflecting surfaces behind the signals. In case of doubt, an assessment by a railway engineering expert is required. The guideline has been formally withdrawn but in Austria is unofficially often still applied for orientation (Ch. VI.1).

VI.3.5 Settings in PV-GlareCheck

Note on application. The following settings are conceivable interpretations and examples of application, not a binding implementation. Whether and how a guideline is transferred to railways and correctly applied in the individual case must be verified independently by the user.

VI.3.5.1 Editor

Height reference. The app takes the Ground level from the elevation data (Ch. 6). On embankments, bridges and in cuttings, the terrain differs from the top of rail; jumps in GL between neighbouring points in "Points and heights" indicate this. There, "Calculate GL automatically" can be switched off and the height of the top of rail entered manually.

VI.3.5.2 Possible filter combinations

When the position paper is applied by analogy, one possible filter combination is the same as for road traffic (VI.2.6.2): "Outside field of view" on, "Luminance" ≥ 30,000 cd/m², "Vertical glare source" ≤ 0.3° with "UNLESS" "Distance to gaze axis <" 10° (horizontal), "Sun overlap" with "+ low sun ≤" 5°, geometric filters on. For signals and level crossings, OVE R 11-3 gives no threshold but states that glare there is not permitted. Further filters can be added at the user's discretion where they are professionally justified.

VI.3.5.3 Evaluation quantities

The evaluation quantities correspond to those for road traffic (VI.2.6.3). For signals, "Min. gaze axis distance" is decisive: it shows how close a reflection lies to the viewing direction towards the signal.

VI.3.6 Notes

• Moving observer: each observation point is stationary; the time during which a passing train driver sees a reflection is not reported directly (Ch. VI.2, section VI.2.7.8).
• Vehicle: cab windows, sun protection and window tinting are not modelled.
• Overhead lines and masts act as obstacles only if they are entered.
• Signals: whether a reflection impairs a signal aspect depends on the position, luminance and size of the source relative to the signal. The app provides direction and intensity; it does not assess whether a signal aspect is impaired.

VI.3.7 Sources

• OVE: OVE Guideline R 11-3 "Blendung durch Photovoltaikanlagen", edition 2016-11-01 (withdrawn 2024-12-01), section 6.2.2.
• Fernstraßen-Bundesamt: Eckpunktepapier Photovoltaik – Blendwirkungen und Blendgutachten, as of November 2025.
• Österreichische Forschungsgesellschaft Straße – Schiene – Verkehr (FSV): RVS 05.06.11 Visuelle Störwirkungen, edition 01.12.2011, section 4.6.

See also

• Ch. VI.2 Road traffic
• Ch. 9 Observation points
• Ch. 10.1 Obstacles
• Ch. V.6 Is the reflection within the field of view?
• Ch. V.8 Filters