Complex sentence: The Tyne and Wear Metro prohibits all photography without written permission from Nexus, the operators of the system, as of 2015 this is the only system in the UK where such a policy is in place.
Split into simpler sentences: The Tyne and Wear Metro prohibits all photography without written permission from Nexus, the operators of the system. As of 2015, this is the only system in the UK where such a policy is in place.