Suburban Roads Research Articles

Delay Doppler characteristics of multipath propagation at 910 MHz in a suburban mobile radio environment

Statistical descriptions of the time delays and Doppler shifts associated with multipath propagation in a suburban mobile radio environment obtained from bandpass impulse response measurements are presented. The measuring equipment which has <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.1 \mu</tex> s resolution in time delay and a data output bandwidth of less than 5 kHz is also described. For the first time small scale statistics of the multipath propagation for vehicle travel distances on the order of 30 m along streets are presented in the following forms: 1) average power-delay profiles made up of over 200 individual profiles, 2) cumulative distributions of signal amplitude at fixed delays, and 3) radio frequency Doppler spectra at fixed delays. Delay spreads for typical suburban streets are on the order of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.25 \mu</tex> s. Extreme cases have paths with significant amplitudes at excess delays of 5 to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7 \mu</tex> s and the square root of the second central moment delay spreads up to about <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2 \mu</tex> s. Often the signal at fixed delays has a Rayleigh distributed amplitude but large departures from the Rayleigh distribution also occur. RF Doppler spectra at fixed delays indicate that some of the multipath is from one relatively discrete scattering center while at other delays several scattering centers distributed widely in angle are involved. The observed RF Doppler spectra are consistent with the cumulative amplitude distributions at the same delays.

Study of the traffic flow control on the paris A6-B6-C6 freeway complex

The problems raised by the overall traffic control of a freeway complex consisting of 3 freeways and 3 “routes nationales” forming a finely meshed network south of Paris have been studied. The optimization criterion selected is the minimization of the total time spent in the system, including the waiting time at the entrances. The controls utilized include traffic signals at suburban road intersections and various freeway entrances, arrowing of routes by means of variable signposts placed at the various branching points in the network, special devices for assignment of lanes, speed recommendation signs and special warning signs. The inputs of the system are: traffic flow, lane use rate, speed and length-of-queue measurements. Regularly spaced detectors allow an automatic surveillance of the network; this detector surveillance is completed by television monitors. The various data are transmitted to central control stations which are interconnected with a “general supervisor” and operate in real time. Each central control station has a computer; the “general supervisor” has, in addition, synthesis vizualisation equipment, as well as manual control devices. The study has sorted out two successive steps of operation; the first one will be to choose control sequences from a preestablished catalogue by means of a comparison between the real traffic situation and situation types; in the second step, the control sequence to apply at a given moment will be selected by an optimization program working in real time.

The Development of Suburban Road Passenger Transport in Leeds, 1840–95

The Development of Suburban Road Passenger Transport in Leeds, 1840–95

Evaluation of the cervical spine in whiplash injuries.

In contradistinction to the crippling and fatal injuries associated with speeding vehicles on our Nation's highways, there is being seen with increasing frequency a more subtle though at times distressing injury in accidents involving vehicles traveling at slower speeds on our urban and suburban roads. These “whiplash injuries” have received considerable attention in the literature, with discussions of their mechanisms (4, 6, 7), physiology (9), treatment (8, 9), follow-up, and medicolegal implications (2, 3). One hundred and seven cases have been reviewed. In our experience, the patient, in most instances the driver of an automobile, reports that he was slowing down or waiting for a traffic light to change when another vehicle struck his car from the rear. He will usually state that his head snapped backward forcibly and was then jerked forward with equal violence. Seletz (9) has described the injury as due to an acute flexion or a severe hyperextension of the cervical spine. Nagle (7) believes that it can occur as a result of striking any object “head on” as well as of being struck from behind. Personal communication with several radiologists indicates a great divergence of views concerning the number of roentgenograms and the projections to be used, as well as roentgen criteria employed, in arriving at a diagnosis of whiplash injury. The attempt made at Meadowbrook Hospital (Hempstead, New York) to standardize roentgen exposures in such cases, and to assess the findings which will contribute to a diagnosis of whiplash injury, forms the basis of this paper. Method Patients considered as having been subjected to the type of trauma described above were examined radiographically by a “whiplash series,” which included the following projections: 1. An anteroposterior view of the cervical spine (supine, Bucky technic at 40 in.) (Fig. 6, A) 2. An open-mouth view of the odontoid (as above) (Fig. 7) 3. A lateral view of the cervical spine, with chin relaxed (at 72 in., standing) (Fig. 2, B) 4. A lateral view in maximum flexion (72 in., standing) (Fig. 2, A) 5. A lateral view in maximum extension (72 in., standing) (Fig. 2, C) 6. A 45° right oblique view (72 in., standing) (Fig. 5, A) 7. A 45° left oblique view (as above) Fifty adult patients, 25 men and 25 women, all of whom had previously sustained a whiplash injury, were compared to 35 normal adults (25 men and 10 women). The paucity of volunteers in this latter group is a reflection of current fear of ionizing radiations. In the normal group, no history of trauma or symptomatology referable to the cervical spine could be elicited. In all instances a low-dose roentgen technic was employed; fast screens, high-speed films, use of cones, filters, and gonadal shielding kept the total roentgen exposure low.

Excavations of Ermine Street in Lincolnshire

The course of the Roman road from London to York, today known as Ermine Street, is well attested. Much of it underlies our comparable modern trunk road, the Great North Road (A1), but there are many deviations. To review the East Midland sector, the modern road covers approximately the Roman road from Huntingdon to the south-east gate of the walled town DVROBRIVAE at Water Newton. Here the modern road bears more to the west and leaves the Roman line. This passes through the ancient town as its main street, crosses the river Nene and continues in the same line until, at a point some three miles south-east of Stamford, it bears more westerly, running west-north-west through Burghley Park. It crosses the Great North Road on the western boundary of the park, where it was exposed in 1732 and seen by Stukeley (1883, ii, 269). From this point its course alters to north-west and, after crossing the river Welland, it underlies a suburban road in the western part of Stamford and crosses the Empingham (Oakham) road (A606). North of this it is seen as a boldly-upraised ridge crossing several fields diagonally until, some three-quarters of a mile south-east of Great Casterton, it joins once again the line of the Great North Road and runs parallel to and immediately adjoining the south side of the modern roadway.

A Comparison between Public Passenger Services in Paris and London

Résuméby Pierre Ruais.This article aims at comparing the public passenger services of London and Paris, with particular reference to their dissimilarities.Public transportation in the Paris area is the joint concern of the State and of a regional agency: the « Office Régional des Transports Parisiens ». This is apparently the first and only attempt at regional management in this field, in France.The entire surface and underground networks have been entrusted, by gradual process of law, to one single body: the « Régie Autonome des Transports Parisiens» (R.A.T.P.). Similarly all suburban road passenger services have been grouped in the « Association Professionnelle des Transports Routiers de la Région Parisienne », acting as the « opposite number » to the Office Régional.The area involved covers approximately 1,200 sq. km., within a 20 km. radius. « De jure », the State continues as the concession-granting authority, but the powers devolved upon the Office Régional are wide, and include determining the participation of the four «départements» (counties) and the municipalities in the budget of the R.A.T.P.The London Transport Executive's competency covers some 5,000 sq. km. within a 30 to 50 km. radius, and includes every type of transportation, with the exception of taxis, long-distance buses, and railways. It is a geographical unit of the British Transport Commission and is the successor of the London Passenger Transport Board, which itself replaced 170 individual operators.In London, public transportation is fully nationalised. In Paris there remains a sector of private enterprise, viz. suburban motor-bus services.In London, a monopoly granted to a single operator in in force. In Paris there are several, and there is no monopoly in the eyes of the law. Co-ordination between the Société Nationale des Chemins de Fer, the R.A.T.P. and the privately-owned bus lines is ensured by the Office Régional.In the Parisian system, financing is borne jointly by the local authorities and the State. In London, the several networks: Underground and bus lines on the one hand, railways on the other hand, mutually compensate their relative budgets in ratio of mileage, after balance of the income and outlay of each.In London, a special tribunal protects the passengers’ interest against that of the operator. In Paris, this task is the concern of the Office Régional.The British system lays managerial responsibility mainly on a small number of specialists. Paris has, even to a fault, respected the principle of representation of all the interests involved.This may lead, within the management, to differences of opinion between the operative side and the passengers and personnel. The British have given preference to laying the onus of protecting these to outside bodies: the Tribunal and a Wages Board respectively. Greater efficiency thus accrues to the management.The London « Pooling Scheme » was of value only as long as there were, as under the London Passenger Act of 1933, several joint operators, viz. the London Passenger Transport Board (buses and Underground) and the four railway companies serving the suburbs. It has become pointless since 1947, when, with full nationalisation, the British Transport Commission took over the total unified operation.In Paris, the networks being completely distinct, any such scheme would be supererogatory, in so far as season or other tickets valid for transfer between the several types of transportation, do not give rise, financially at least, to joint operation.The author does not feel that any transposition of the London regime to Paris would be beneficial. He admits however that remedy should be sought for the present financial situation, though the predominance of the concept of « public service » must ever remain in the forefront, in the case of passenger transportation.

Association News

The Phi Chi Fraternity will hold a luncheon Thursday, June 14, at the Statler Hotel. The assembly will be addressed by Eben J. Carey, professor of anatomy and dean of the Marquette University Medical School, Milwaukee. <h3>Banquet of Section on Gastro-Enterology and Proctology</h3> The annual banquet of the Section on Gastro-Enterology and Proctology will be held at the Hotel Cleveland at 6:30 p. m., Wednesday, June 13. <h3>Beware of Speed Traps</h3> A physician who has evidently had some unpleasant experiences desires that those who drive their own cars to the Cleveland session be warned to keep under speed limits in all suburban areas around the city of Cleveland. Officers patrolling suburban roads do not ride on motorcycles but drive Ford cars and are said to be vigilant in arresting those who drive at a speed in excess of the ordinary limits. <h3>MEDICAL BROADCASTS</h3><h3>National Broadcasting Company</h3> The American Medical Association