Complex sentence: For passengers who cannot use stairs, platform 3 may be reached across the causeway from the car park, a stairlift goes from the road-level footbridge to platforms 4 and 5.
Split into simpler sentences: For passengers who cannot use stairs, platform 3 may be reached across the causeway from the car park. A stairlift goes from the road-level footbridge to platforms 4 and 5.