Transport For London's Mark Evers talks to Peter White about why their physical assisted guidance keeps being withdrawn. Now it's reinstated again, will they be able to keep it that way? And our reporter Johnny Cassidy looks at the world of the binged TV box set. Why isn't audio description available on every episode when a box set is placed on an on-demand TV service? Channel 4 took some time to make audio description available via its All 4 service for every episode of its new hit show "It's A Sin" (produced by the Red Production Company). PRODUCER: Mike Young