Tag 'source = estimate; extrapolate; survey; video'

• 4: railway:signal:speed_limit:height
• 4: railway:signal:speed_limit
• 4: railway:signal:speed_limit:form
• 4: railway
• 4: railway:signal:speed_limit:speed
• 4: source
• 4: video
• 4: operator
• 4: railway:signal:direction
• 4: railway:signal:position
• 2: description