Sir, Lorries may result in congestion on the A34 but no amount of rail investment will divert that traffic on to the railways.

There is already a container train every hour from the docks at Southampton (and probably room for more).

Most of the lorries are on internal UK journeys where the economics are heavily stacked against rail. The problem is not capacity, it is cost. Building capacity would probably make the situation worse.

In an ideal world, lorries would be properly charged for their environmental damage, and the economics might start to shift some of the lorry traffic onto rail. But the bulk would remain on the roads. No government is going to change the economics sufficiently to eliminate congestion on the A34 by that means.

If we want railways to contribute to easing congestion on the A34, the only practical means is by diverting local traffic on to the railway.

It is the heavy local traffic that causes the junctions to seize up. The local traffic is also fairly concentrated on certain corridors to and from Oxford, and so it's reasonably easy to give those motorists a viable choice.

Introducing a fast Bicester-Oxford rail service would be quite an expensive gamble. But it's a far more realistic objective than diverting the lorry traffic.

The county ought to be advocating such a service, and not allow themselves to be distracted by grandiose station-rebuilding schemes, or through running to Bedford. Bicester in 15 minutes should be the objective.

Richard Mann, Oxford