ROBERT EVANS suggesting a heavy increase in train capacity on the Brighton line’s Balcombe Viaduct (Letters, August 5) overlooks the urgent need to have four tracks between Three Bridges and Brighton in order to separate the overloaded fast and stopping train services.

Kent has a high- speed railway across the county. Sussex will be left behind if there is no coastway high-speed railway to the Channel Tunnel. Similarly the Brighton line needs to cut down rising congestion as the Southern England population trebles.

As far as the Victorian Balcombe Viaduct is concerned, increasing train capacity using Electrostar trains twice as heavy as the old slam-door trains probably would considerably reduce its life.

John Stanaway Lorna Road, Hove