HEAVY MOTOR TRAFFIC.

26th December 1918, Page 8

26th December 1918

Page 8

Page 9

Page 8, 26th December 1918 — HEAVY MOTOR TRAFFIC.

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An Analysis and Criticism of the Recommendations of the Local Government Board's Committee as Regards Commercial Vehicles and Motor -Omnibuses.

General Principles.

IN OUR LAST ISSUE we informed our readers briefly as to the character of the main recommendations put forward by the Departmental Committee appointed to consider the Laws and Regulations relating to the Construction and Use of Heavy Motor Cars. Before dealing with the items in more detail, it is advisable to try to indicate the general consensus of opinion of the Committee on fundamental matters.

It is stated that the evidence given has clearly proved both the past and the inevitable future development of heavy mechanical transport, which has now been recognized as an essential factor in the commercial and induatrial life of the nation. Such being the case, the natural gro-wth, of the movement must not be checked or cramped in any way. Also, it has been proved that it is quite possible to construct and maintain roads capable of carrying heavy motor traffic efficiently at a cost which, equitably adjusted, would not be unreasonable.

The next point is that, as the traffic grows it becomes less and less local in character, and; therefore, the roads must be treated less and less from a purely local standpoint. The Committee was not required to make recommendations on the subject of the finance of road reconstruction, buta appears to indicate its adherence to the principle of the classification of roads and the provision of assistance, by direct grants from the Exchequer, in aid of the maintenance of the more important thoroughfares. We thus have a proper realization of the position which heavy motor traffic must be permitted to occupy and, broadly speaking, of the fact that roads must be made for the traffic and the traffic must not be cramped in order to be suitable to antiquated roads. Thus, we start on a thoroughly satisfactory basis. If on examination any of the recommendationsof the Committee appear to run counter to the general principles explained, we have strong grounds upon which to base our protests before these recommendations become law.

We must, however, remember that a free acknowledgment that our existence is justified does not amount to a general permit to make nuisances of ourselves. Damage to roads by heavy motor traffic is attributed variously to great weight, bad distribution of weight, small wheels, the effect of propulsive effort, the use of steel tyres on cambered roads, the action of solid rubber tyres in contact with the road surface, the pinching effect between twin tyres, the hardness of rubber tyres when worn, the consequences of impact and speed, and some disregard for the existing regulations. in the case of the motor omnibus, special causes of damage are stated to be, the constant passage of vehicles of identical construction ; the frequency of stopping and starting, often at fixed points ; the character of the load and the springing of the vehicles.

Regulation of Bus Traffic.

The Committee considers that, where cases of thoroughly serious road damage can be proved, the offender is generally the motorbus, the'reasons being roughly those stated above. It is realized that regulation of all heavy motor traffic by local authorities would be very difficult to apply in practice. On the other hand, motor omnibuses are already subject to c28 control as public service vehicles, requiring to be licensed as such. Further' they generally ply along s Thus, the Committee comes to the conclusion that a control.on the lines laid down in the Local Government (Emergency Provisions) Act of 1916 ought to be continued and made a permanent portion of the law. This Act provides that new routes shall only be established with the consent of the highway authority or, if that consent is unreasonably refused, with the consent of the Local GOvernment Board.

The Committee has not considered the question from the point of vieF of whether, or no, local authorities ought to make a mileage contribution by motor omnibus traffic a condition of the granting of the licence. Its attitude is dictated rather by the feeling that the motor omnibus service is local in character and calculated to do particular injury to certain roads owned by specified authorities, and, therefore, that some control is feasible and reasonable.

It is, however, felt that a multiplicity of licensing authorities is undesirable. There should be a wider local unit of administration corresponding to the wider radius of action of the motorbus. A more uniform system of licensing is required and the right of appeal to the Local Government Board is necessary. In the event of the Board consenting to the establishment of a service, it is clearly undesirable 'that the licensing authority should be able to negative the decision by withholding licences from properly constructed vehicles. The Committee considers that the use of deeper tyres and longer springs on buses, even at the expense of the additional weight entailed, would be beneficial to the roads. It does not make a definite recommendation on this subject, but it advises that the overhang behind the rear axle of a bus should be limited by law to seven-twenty-fourths of the over-all length of the vehicle.

Dimensions of Goods-carrying Vehicles.

This limitation of overhang is proposed also to apply to all heavy motorcars. A further new proposal is that the maximum over-all length of a heavy motorcar shall not exceed 26 ft. We agree that the regulation with regard to overhang is perfectlyreasonable and is, in fact, desirable from almost every point of view, but we fail to see much point in prescribing a limit of over-all length. Apparently, the Committee also considered the question of imposing regulations which would have had the effect of prescribing the minimum wheelbase in terms of over-all length. We are glad that this proposition has been abandoned. Very strong arguments are required to justify any laying down of dimensions, or interference with the freedom of designers. Unless great care is taken, natural development may be impeded and much harm done by restrictions of this class.

Vehicle Weights and Aide .Weights.

We freely admit the necessity of some limitation of laden weights and axle weights; or, at least, of the latter. In this respect we consider that the Committee might have done better, but most certainly might bare done worse. It is not suggested that the present limitations of axle weights should be altered, but it is proposed that unladen weight shall be increased, that of the vehicle itself from five. to six tons and that of the vehicle and trailer together, from six-and-a-half to eight tons, the ughladen weight to include all the parts ordinarily in use when the. car is working, but not to include water, fuel, accumulators used for propulsion,

There is more reason in giving powers for checking laden weights and axle weights. Hardened offenders must certainly be brought to book and the evasion of examination must not he made too easy. The danger of giving wider powers in this respect is that these powers may be frequently abused, by petty-minded local authorities. Consequently, all this section of the report will need very careful examination with a view to the possible recommendation of a more simple alternative procedure.

Tyres and Wheels.

The whole tenor of the report favours the use of rubber as against metal tyres. With this we are entirely in agreement and, on the whole, we think that the proposals of the Committee under this heading can only be beneficial. The main points are that it is proposed that no steel-tyred vehicle shall have a legal speed limit of over five miles an hoar, and also that a rubber-tyrecl vehicle drawing a rubber-tyrecl trailer shall be permitted to travel at eight miles in hour. The latter is a most important and advantageous alteration. The former is in our opinion good, simply because it means that rubber tyres will become practically universal. This we consider to be to the advantage of users and manufacturers, as well as of the public responsible for payments toward road maintenance. The protection afforded by a rubber tyre more than balances the cost of that tyre's maintenance, and, if the presence of the rubber tyre means a higher legal speed, greater economy in transport almost inevitably results from its use.

The Committee is all in favour of increases in wheel diameter, and we do not think it goes too far in this respect, particularly in view of the fact that oversea markets are becoming increasingly important and, in respect of these markets, reasonably large wheels are always essential.

We do not propose to go into details as to the proposals with reference to metal-tyred wheels, as we believe these will presently become practically obsolete. • The minimum wheel diameter in their case is to be 2 ft. 9 ins, for the lighter classes of vehicle,with a. graduated scale under which, for an axle weight between five and six tons, the minimum will be 3 ft. 6 ins., and, for an axle weight exceeding six tons, the minimum will be 4 ft. In the case of solid-rubbertyred vehicles the minimum diameter of any wheel will, if the Committee's recommendations are adopted, be 2. ft. 6 ins. inclusive of the tyres. Thus, we May look forward to the time when every five or six-ton steam lorry will be rubber-t3rred excepting, perhaps, sonic of those built before the new rules come into force. It is not suggested that any of the regulations should be retrospective so as to apply to existing vehicles, or to those in course of construction when the changes in the law are made.

Trailers.

The principal recommendation with regard to trailers has already been chronicled. It is that the legal speed limit of a rubber-tyred trailer behind a. rubber-typed vehicle shall be. increased from five to eight miles an hour. The Committee sees no objection to the practice of double licensing of tractors, both as heavy motorcars and as road locomotives. It does not consider that a heavy motorcar, running as such, should draw more than one trailer. It recommends that the aggregate axle weights of all the axles of a trailer should not exceed eight tons and that metal-tyred trailer wheels should not be of less than 2 ft. 6 ins, in diameter, the tyres to have round edges. The Committee does not favour the attachment of trailers behind passenger-carrying heavy motors, its refusal to adopt this proposal being based upon the belief that dangers would be introduced. No alteration in the law is suggested in respect of road trailers. We consider that further consideration should be given to some branches of this question. The prohibition of trailers behind passenger-carrying vehicles may -be reasonable if the trailer-is imperfectly controlled, but we question whether it would be justified if a, suitable system of trailer connection were employed. We are left in. some doubt as to the-, egal position of the device known as the "semi-trailer," and we see no encouragement whatever offered to any system in which the wheels of the trailing -vehicle are positively driven so as to assist in the propulsion of the combination. This is clearly a desirable -development which should be encouraged.

Speed.

No changes in the existing speed limits are suggested, excepting those already mentioned, having the effect of reducing the legal speed of the three-ton steel-tyred vehicle and increasing that of the rubbertyred vehicle with a rubber-tyred trailer.

Free Use of Roads and Bridges.

The Committee does not find that it is practicable to suggest that heavy motor vehicles should be con'strained to use only selected roads or to refrain from using roads unsuitably constructed for them. The only suggested exception is in the case of the motorbus service, already discussed. The classification of roads for the purpose of restricting traffic is regarded as impossible, and also as highly undesirable in its inevitable effect of hampering progress. The Committee advocates amendments in the law, providing more effective measures far the strengthening and improvement of bridges not fitted to stand heavy traffic, and for removing and preventing the imposition of unnecessary restrictions of the use of bridges.

Miscellaneous Points.

Evidence was taken on the subject of splashguards and of lifeguards. As regards the former there does not appear to be any device sufficiently practical, in. the Committee's opinion, to justify its general adoption As regards the latter, progress has not gone far enough to justify anything more than a general recommendation that something,in the way of a,lifeguard is desirable, and that steps should be taken towards improving and utilising such fittings.

It is considered that the question of legalizing the pedrail system should be dealt with when the opportunity arises. _Heavy motor vehicles should, be required to be fitted with mirrors enabling the drivers to see overtaking traffic, and thus to eliminate some degree of unintentional obstruction.

Finally, it is suggested that the design and conr struction of special types of vehicle, calculated to do less damage to the roads, should be encouraged by public funds, and that proper facilities should be given for trials and demohstrations of any type of vehicle, which, for,the time being, cannot ordinarily use the roads without committing a breach of the law..

This last is distinctly a desirable provision,-not only in itself, but as indicating an opinion that' the law,' even when amended, will not be permanently perfect,but will require frequent and free review and revision in order to prevent it from acting as. a, hindrance in the way of desirable progress..