• Experts Gather at This Week's Public Works, Roads and Transport Congress, and Discuss, Among Other Subjects.
Page 44
Page 47
If you've noticed an error in this article please click here to report it so we can fix it.
Road Design and Transport Control
THIS week's programme of the Public Works, Roads and Transport Congress, at Olympia, London, has been full. It began on Monday with the opening of the congress and exhibition by Mr. Attlee, the Prime Minister, with Mr. Aneurin Bevan, Minister of Health, in the chair. Then the conference proper was opened by the reading of two papers, one of the authors being Mr. A. J Lyddon, C.B.E., M.Inst.C.E., former chief engineer to the Ministry of Transport. He dealt with "The Highway Engineer and Road Safety," and spoke under the auspices of the Royal Society for the Prevention of Accidents.
The programme included discussions of 22 subjects of importance to municipal and public-works engineers. Four of the papers of interest to readers of "The Commercial Motor" are reviewed here. The vehicle exhibits were described in last week's•issue.
How Highway Engineers Can Aid Safety NAIL LYDDON said that he had been asked by the Royal 0/1 Society for the Prevention of Accidents to suggest the extent to which highway engineers could limit the chances of failure of human beings to observe precautions as road users. His answer was that segregation should be the keynote in modern road design. It could be in relation to destination, classes, direction, grade separation or time. More cycle tracks and pavements would be a help towards road safety. The provision of dual carriageways to increase traffic capacity would make a great contribution to road safety.
Quoting other authorities, he said dual carriageways should be built where an existing road carried 400 vehicles at the peak hour, but would often be justified on roads carrying lighter traffic. Where space did not permit building dual roads, safety could be increased by erecting refuges and introducing one-way streets. • Segregation at different levels meant the use of fly-overs or under-passes. This was expensive and used much space, and should be a long-term matter. Time-segregation meant traffic signals.
The general principles of safe design needed constant application. It was to be hoped that at no distant date there would be a category of motor (one-purpose) roads, in addition to the existing classes.
Front America it was reported that the motor road offered a big advantage in reducing collisions between vehicles. The elimination of cross-traffic and the provision of the central divisions to form dual carriageways added greatly to the safety of driving. On two comparable highways in Connecticut, each 37 miles long, the fatality rate of collisions between vehicles was almost four times greater on the all-purpose road than on the alternative motor road.
The standard of design adopted for the improvement and maintenance of any highway system should be developed with safety as the primary factor. Every attention must be given to methods of protecting the pedestrian, because we were all at some times pedestrians.
Many contributions to safety could be made in the execution of highway maintenance. There was no great' degree of permanence in a highway.
Road junction Designers Must Be Bold THE object of his paper, said Mr. G. T. Bennett, 0.B.E., B.SC., M.I.C.E., M.I.Mun.E., county surveyor. Oxfordshire, was to suggest that there was need for research, chiefly by experiment under practical conditions, to determine the safest designs for road junctions of the more simple general types.
He declared that no adequate research had yet been carried out and designs put forward represented opinion based on general observation and experience. He had doubts as to the sufficiency of existing designs.
After showing how the right-hand turn was responsible for 90 per cent, of junction accidents between two vehicles, he said that the right turn could not be eliminated by the introduction of roundabouts or even more ambitious types of junctions, such as clover leaves. The problem, then, was to improve the safety of the right-hand turn, rather than to eliminate it.
Was it possible, he asked, to design a junction so that the sudden right turn could not be used and the gradual veer to the right was enforced on drivers? Obviously this could be done by making the junction into a vee, or if it were already so, by avoiding the usual _alteration to a square entry. The disadvantage would then be that there would be no check on the speed of minor-road traffic entering the major road, which check was the understood reason for the existing " square " design. This check could be simply provided by its insertion in the minor road itself just before the junction was reached. Symmetry Must, however, be achieved and the result was a "baffle" design with two-way traffic on each side of an elongated half-moon shape, with the flat side away from the minor road.
The adoption of this simple principle would appear to meet the requirements of slowing down speed at entry into the major road and at the same time giving minimum angles between meeting and intersecting lines of traffic.
Mr. Bennett gave examples of how staggering of crossroads could be avoided, and how, where they already were staggered, suitable modification could be arranged. All the evidence, however, pointed to the need for easing the difficulties of the right-hand turn at junctions, Practical tests were the only answer to contentions made either one way or the other, and he hoped that a case had been made out for such tests.
If existing designs were suspect at all, they could be improved only by breaking pne or more of the principles on which they were based. There should be courage in making experiments in the interests of road safety, so serious was the accident position generally. Over 40 per cent, of accidents occurred at junctions, and if 80 per cent. of these were caused by vehicles turning to the right, any reduction in accidents of this type might have a measurable effect on tlib national accident position.
Selecting Locations, for Future Roads IN a paper entitled "Road Location and Design," with Special Reference to Motor Roads," Mr. E. C. Boyce, B.Sc., A.M.I.C.E., M.I.Mun.E., county surveyor, Gloucestershire, considered both principles and practice as applied to this subject.
The first consideration, he said, was the avoidance of urban development and built-up areas. Regard must be had not only to what existed but to potential building development that might take place in the future.
There should be as little interference as possible with the efficient operation of farmaioldings through which any new route must pass.
The cost of any scheme must be a paramount consideration in design and construction of a new road, It was difficult to define where engineering ended and economics began,
Points of entry and exit should be limited and there should be no crossings level with existing roads. Where a new road crossed an old one it must either pass over or under it, depending upon relative levels. At major intersections connections could be provided in a variety of ways, including the donble-deck roundabout or the clover leaf-, an alternative was a three-level fly-over
In the locations stage the ultimate general form of construction of the new route must be borne in mind. There was no evidence to show.that roads being designed at the
present time, or the principles enunciated by the Government on which such designs should be based, have been related to the performance of the vehicles that would use them.
Considering the question of the future types of motor vehicle, in relation to roads, he said that with regard to commercial vehicles there was no doubt that, but for restrictions imposed by law, vehicles in this class could comfortably sustain a speed of 50 m.p.h. for long periods.
Virtues of Centralized Municipal Transport S° QOMEWHAT more closely related to the road transport industry was the paper, "The Advantages of Centralizing Municipal Transport (Non-passenger)," by Mr. A. Connor, Finst.P.C., transport manager and director of public .cleansing, Derby.
The present-day insistence so rightly placed on planned ecortomy, he said, was leading more and more to the realization that only by the centralization of a local authority's transport could full benefit be derived from the advantages inherent in the use of mechanical transport.
.During the first 18 months of the operation of a central department in his own town it was found possible to reduce the size of the fleet by four vehicles and increase the percentage of the effective time worked by the remainder from an average of 92.4 per cent. to one of 98.4 per cent.
A 'first consideration, upon centralization, was to adopt a planned replacement of obsolete or worn-out vehicles, and standardize on the fewest possible makes and types.
The officer in charge of a central department would place great reliance on accurate costs and comparisons in enabling him to assess the merits of alternative makes and types.
On the repair and maintenance side, there were obvious advantages of centralization in the employment of skilled mechanics, coachbuilders and painters, autn-electricians, tyremen and welders. All repairs and overhauls could be undertaken in the department in order of priority.
One large well-appointed garage enabled all vehicles to be kept under one roof, except in the larger cities and was conducive to better supervision.
Mr. Connor suggested that the public cleansing department was the one best suited to be combined with that of a central transport department. The director of public cleansing was the largest user.
• The• speaker went on to describe in some detail the features and layout of the garage and workshops of Derby Corporation. The garage was 225 ft. long by 105 ft. wide, giving an area of 2,625 sq. yds., with a minimum height clearance of 17 ft. There was an impervious floor surface with drainage channels and a floor area completelyfree from supporting stanchions. Heating was by steam unit heaters suspended from the roof.
The equipment of the workshops was such as to bring all repair work within 'atieir scope. There were 34 skilled tradesmen and assistants. Vehicle strength was 152, there being 27 cars, 9 ambulances, 34 vans, 49 general-purpose lorries, 21 refuse collectors and 12 special types.