asked the Parliamentary Secretary to the Ministry of War Transport whether he will give directions that derelict lines of railway shall either be reopened for traffic or dismantled, so that the rails can be put to some useful purpose in the war effort?

The Railway Executive Committee has already taken action to ensure that appropriate use is made of any tracks no longer required for traffic purposes.

Does the same thing apply to tramway lines in streets?

The old tramway tracks are being taken up as labour is available to do so, and also to replace the road surface afterwards.