Save a fortune with Forth bridge rethink

SO THE Scottish Government is having difficulty in financing their proposed Forth Replacement Crossing (News, April 5).

Part of the problem is that for 4km of new road and 2.7km of bridge, they need 2.3bn at 2016 prices, ie 343m/km. This extreme cost per km is probably due to the Forth proposal being "iconic" and "unique", crossing both the Rosyth and Grangemouth navigation channels.

A simpler, cheaper and more functional crossing, similar to the Second Severn Crossing, could start at the Dunfermline spur off the M90, thread between Rosyth dockyard and the site of special scientific interest (SSSI) avoiding both, ending at the M9, Junction 2. This would reduce costs by just under 1bn.

This crossing would reduce the adverse environmental impact, with less land used, no SSSI bisected, no listed buildings demolished, no need to dig up the Queensferry Road, and much improved public transport provided when the new M9 lanes become bus lanes after the old bridge is reopened.

The savings are due to simplifying the bridge and reducing the total distance to approximately 5km, including 3km of approach roads. The 5.1km bridge structure of the Second Severn Crossing would cost 700m (4% annual inflation assumed) at 2016 prices. Similarly I have allocated 300m for the end junctions, 350m for building a third lane each way between Junction 2 and the Edinburgh bypass (costs taken from the M1 widening), and 125m for refurbishing the old bridge to carry cars and buses. Despite these pessimistic estimates the total cost would only be 375m more than the 1,100m the UK government is offering, that is 825m less than the Scottish Government's unique and iconic symbol.

The Scottish Government does not suffer from a lack of funds, but a lack of imagination.

Ross Carruthers FICE, Perth