that if one flies over London at a time of dense traffic, expecting that little or no road-surface will be seen from the air but only vehicle tops, the reverse is more true ! So that road space and speed are available, as well as the will to use them. It follows then that there is something wrong with the arrangement and with the use of the streets as administered. As to the arrangement there is no doubt, historically, that the streets were laid out, their name-plates fixed up, their absurdly sharp corners made, the road rules and customs instituted, all from the horse-drawn standpoint. A horsed cart can turn round on its tracks in any road, a car in almost none. The cart can round the right-angled pavement corner as we know it without the near wheels quitting the gutter. A car must take a much wider sweep-generally on a circle of some 40 feet diameter or more (except taxi-cabs, which require 25 feet circle). The horse recovered while resting at a traffic stop, the car continues to burn petrol at five-sixths of its working rate. The horse could not be stopped rapidly from what were to it high speeds like 12-15 m.p.h. The cart did not come from long distances, hence its driver as a rule knew the road names and the short cuts on his beat, or in the exception he moved slowly enough to be able from his exposed seat to ask his way without stopping-and more useful still, to be taught road manners by the caustic tongues of his neighbours. All this is gone and the car has come; but no technical provision is made to utilise its qualities or minimise its faults, and but little administrative effort until this year when we got a few round-abouts. These are an improvement all too tardily adopted. They have been suggested in the Press and personally for many years, but it appears that till time removed an obstructionist who had a brief authority, we were compelled to stand still.

To-day 'round-abouts' are much discussed again. You approach the round-about intending to cross it in the direction of some road on the far side-you are told to go round by the left until the circuit brings you to the road you want. There you quit the round-about tangentially, having lost time only to the extent of the slightly longer distance covered. That is the theory. In practice the roads are not tangential, they are per

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pendicular to the circle; the circle is not round, and you enter or leave it only after negotiating the curve of the sharp-angled pavement corner. It is to be observed that the size of the circle must be greater the more traffic there is, otherwise the round-about fails. The reason for this is that the incoming traffic must be able to infiltrate itself into the line of circulating vehicles. Should these be close-packed nose to tail you cannot get in till a constable stops the circulation to create a gap for you. When this happens the round-about fails. It will occur oftener if the roads which debouch into the round-about are not trumpet-mouthed; in other words, if they prevent the tangential entry and exit-and that is the position at present. The reason why road pavements are not flared or trumpet-mouthed both for the roundabouts and at every road confluence is simple. It is the will of many pedestrians-that is to say, the voters-to retain a convenience they had in the day of the horsed-cart. The pedestrian who declares himself the enemy of all concessions to the motor forgets that even though he never enters a car or 'bus he is one of the most important motor users in the State. His daily work, the raw materials for it, the input and output of the industries from which he draws his means of livelihood, the delivery of his food and his utensils, all depend on motor-cars. By reading his letters to the Press I have formed the impression that he is either self-deluded or selfishly blind to the point which demands awakening. If pavement corners are flared it is clear that the pedestrian must either cross a rather wider roadway at the flared part or proceed down the side street for the two or three yards necessary to give him a crossing of the old width. This is a concession asked from the pedestrian; it must be made voluntarily for self-interest—just as the paying of taxes is a concession made voluntarily for the same

reason.

The insufficiently flared pavement corners are a legacy of the horsed traffic days. The larger turning circle of the car causes need for change. Suppose a goods motorvan to-day proceeding along the extreme left of a street. It cannot be steered off into a side road on its left without swinging outwards towards the crown of the street it is in, or of the side road it is entering. Since it

may do one or other or both, there is a threat to the traffic in both; therefore the nearby drivers must go canny and the flow suffers. The van-driver extends his right hand to signal that he is quitting the kerb to turn; the signal passes from hand to hand, and the procession, all too slow already, goes slower. Why? Simply because of the acuteness of the pavement corner. If you think of it, the mere fact that a motor-van on the left is going to take itself out of the procession toward the left should cause all behind it to move up one—i.e. a small improvement of the flow instead of a small retardation.

One retardation may be small, but the sum of these constantly recurrent deductions from the very limited average speed reduces our actual travel to the despicable 6 or 7 m.p.h. of some big thoroughfares. Let us remember that if this speed could but be doubled the visible number of vehicles on the road would be halved, for the same amount of transport. In fact, a jamb would be changed to a free flow. Halving the number of vehicles on the road at once doubles the spaces between them and allows of easy infiltration of traffic from side streets -so this apparently trivial matter of flaring the pavement corners becomes not a trivial matter at all, but a dominant one. Luckily, it is not seriously expensive, the real gainer when it comes will be the ratepayer, i.e. the pedestrian.

Further, it is worth considering what happens if our goods-van has to take some side road on its right. After signalling it must not only cross the path of all vehicles travelling in the same sense, but subsequently the path of all those coming towards it. Latterly the police on point duty have tried to encourage a driver who proposes to take a right-hand turn to edge his way previously towards the crown of his road, when he must stop till a pause of the traffic facing him occurs or is made by the man of law. The sooner the constable is advised of this intention the better he can assist it. In Prague, for instance, provision is made for this. Every motor-car carries outside, on the dashboard or windscreen, a dial over which moves an arrow that the driver is obliged to operate. The arrow must point left, right, or straight, according to the course desired; and it has proved very useful both to the constable on point duty and to

approaching drivers, who can shape their course accordingly. It is the traffic itself that blocks the traffic, and, therefore, it is most important that the traffic shall everywhere and always help the traffic when it can, and this assistance will be much facilitated by knowing what it is that each item of traffic desires to do; every one agrees that a punctilious observance of road courtesy would help much, but can this be assisted administratively? I think so.

Consider, first, the potentiality of speed that is wasted in London. Every street has what may be called a speed ability or speed characteristic which varies according to the hour, the day of the week, and sometimes according to the season. Piccadilly in June, for example, is good for 25 m.p.h. at three o'clock in the morning; but only for 5 m.p.h. at three in the afternoon. In fact, the speed potentiality varies throughout the day, and could be summarised by a curve showing its speed value for any hour. I will speak of Piccadilly and its circus as a type-though the argument extends to any congested line; for Bishopsgate or the Clerkenwell road will have different speed curves-and they too will vary with the seasons-but differently. There is no insuperable difficulty about keeping the curves correct if they are useful, and they are, or may be made, extremely useful in my view.

I will recall that the telephone service some time ago warned all subscribers that the hour of heaviest duty was 11 a.m., and that those who wanted to get through quickly should avoid that hour if possible. The same principle can be employed for the streets-if only we have this traffic survey-and if in addition all streets are thoroughly well marked with name plates low down on both corners and opposite to every road junction.

The difficulty in London, and no doubt in other towns, is to bring into use the roads which an aerial survey shows to be free. For the service of the eleven million persons of Greater London, thousands of vehicles, every morning of the year, are on one side of the town with orders to go to the other side. Their owners have no interest in the precise course taken provided it be the shortest in time. The driver shares this indifference, with a qualification. He knows the way via the main thoroughfares, and he knows that their state of Vol. 247.-No. 490.

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congestion is admitted in his time allowance. He knows that it is extremely hard to get good information as to an alternative route, whether before or during a journey ; while it is quite easy to sit and wait at the traffic blockages. He knows that he cannot ask his way from other drivers while he proceeds, and that it is arduous to turn back. He knows, as we all know, that once he has lost his bearings, the chance pedestrian consulted is mostly 'a stranger in these parts myself,' and that when at last redirected, the constable or other kindly adviser invariably sends him back, either into the well-known and well-congested thoroughfare he is striving to avoid, or into another with the added detriment of being unfamiliar.

To consult the map of London is moreover to thousands of people extremely difficult-it must (compared with rural maps) be a very large-scale map, say twelve times the size. Almost all maps published, except the 'six-inch ordnance,' are so adjusted and simplified as to be great offenders, by guiding people into the main arteries, and the lesser-scale maps are to my knowledge misleading in the very streets, the small streets, that should be brought into common use; while, finally, he who takes a gambling shot at a side road that looks helpful will, all too often, be forced away from his objective or be landed in unexpected places.

To

London has reached the paradoxical state where a widening of, say, Piccadilly, though inordinately expensive will not relieve its congestion, because this will increase its attractiveness as a thoroughfare pari passu. augment the size of the exits will also fail, since exits are also entrances. It would seem that there is but one key to the lock, one class of activity which can reopen the door, and that is to help all those who don't want to go to Piccadilly not to go there-and I repeat that I am merely using Piccadilly as a type place for all analogous tangled knots.

To turn the key we need a statistic not hitherto envisaged: a statistic of traffic intention. Officials have counted cars as they pass and noted their direction, east and west and the rest; but this is a half measure ignoring that many, perhaps most, of the drivers neither wanted to be where they were nor preferred the direction or