§ Mr. Gresham Cookeasked the Minister of Transport and Civil Aviation why designs of bridges for the proposed St Albans—Dunchurch motorway include a centre pier, when experience abroad shows that its inclusion is not in the interests of road safety; and whether, since a common practice abroad is now to exclude such a pier, and no structural difficulties are involved, steps can be taken to avoid its use in this country.
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§ Mr. WatkinsonAll the bridges over the proposed St. Albans—Dunchurch motorway involve skew spans, which may be as great as 250 ft. To construct them as single span bridges would require a much greater constructional depth and would result in a considerable increase in cost; it would also double the steel requirements. The central piers will consist of circular columns 4 ft. 6 in. in diameter, 20 ft. apart, on the central reserve, and I am satisfied that they will not be a source of danger.