The Economics and Politics of Tolls on British Estuarial Crossings, with particular reference to the Humber Bridge.

The whole principle of levying tolls on certain highway links in the UK has become controversial in recent years. Many of the salient arguments assume particular relevance for the Humber Bridge because of its low traffic volumes and toll charges which are by far-the highest in the country. Nevertheless, it is instructive to begin this section with an overview of the toll issue as a whole.

One of the main government justifications for road investment is to provide benefits for commerce and industry. The underlying principle is thus maximization of user benefits, with the costs being borne by the exchequer. It is argued, however, that estuarial crossings provide exceptionally great benefits to users and at a far higher unit cost than other parts of the highway network. Consequently the direct beneficiaries are required to pay for these facilities. The 'user pays' principle, which is thus given precedence over that of maximizing user benefits, forms the basis for levying tolls on estuarial crossings.

The high capital construction costs are not in themselves necessarily controversial. What is disputed by road users and the freight lobby as exemplified by umbrella organizations such as the Confederation of British Industry (CBI), Freight Transport Association (FTA) and Road Haulage Association (RHA), is the precedence given to the 'user pays' principle on estuarial crossings.

Anomalies currently exist at two levels:

(i) Trunk roads are free of tolls, except where they cross certain estuaries, despite the rapid increase in the capital costs of road construction and maintenance over recent years.

(ii)Government policy is not consistent even with regard to estuarial crossings. As Figure 1 illustrates, there are eleven tolled crossings in Britain, but at least eleven others remain untolled. Several of these are located close to tolled facilities e.g. Clyde Tunnel near the Erskine Bridge and Blackwall Tunnel (and projected East Lnndon River Crossing) near the Dartford Tunnel. They are likely to divert a fair volume of traffic away from the tolled crossings, generating potential congestion at the former while simultaneously undermining toll revenue maximization on the latter. How this anomalous situation in both principle and practice arose is unclear but it is surely self-defeating in the cases just cited, quite apart from the obvious equity considerations involved.

Clearly, then, the status quo requires revision. Two broad alternatives for achieving a consistent policy exist. Either tolls should be abolished so that all trunk roads are toll free; or, if the principle of levying tolls is felt to be valid, the practice should be extended to - all estuarial crossings at the very least, and possibly also to additional categories of road.

Several other factors have relevance to the policy debate, and this analysis now moves to consider briefly the economic theory underlying tolls, and then the economic position of existing tolled estuarial crossings.