Plans to build Britain’s longest road tunnel – which have been in the works for 15 years without any progress – have cost £300 million so far. The Lower Thames Crossing, which was proposed to ease congestion on the Dartford Crossing, would connect Kent and Essex. It is expected to cost around £9bn for the whole 2.4-mile project, which would be built in Gravesend. Recently, it was revealed the development is the longest planning application on record with a whopping 359,866 pages spread over 2,838 separate documents. There are so many pages of plans, arguments, and comments that if every page o…