The government publishes its latest economic case for HS2 on Tuesday, hoping to persuade people that building a high speed rail line through the UK is worthwhile, despite the spiralling costs.

In order to cover the HS2 story, BBC News has used a "hexacopter" for the first time which allows the filming of locations and angles that previously would not have been possible.

Transport correspondent Richard Westcott reports on what difference this kind of technology will make to news.