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A traffic engineer emphasizes the common interest of public transport and traffic engineering, examines the practical problems and explains how computer techniques can help
BECAUSE traffic demands are related to broader questions of transport and because schemes of improvement-take time to prepare and must be compatible with one another, an especially important aspect of the traffic engineer's work is transport planning. In this, the engineer's work is complementary to the work of the public transport operator, providing information on the present situation, estimating future passenger demands, exploring the factors which affect people's choice of transport, planning new roads and assessing the way in which alternative transport systems may be used. These views were put forward by Mr. G. Brian Parker, MA, IVISE, DipTE, DipTP, MICE, AMInstHE, when he presented a paper "People must go: a traffic engineer's approach to road passenger transport" to the annual conference of the Scottish Road Passenger Transport Association at Aviemore on Wednesday. Mr. Parker is an associate of R. Travers Morgan and Partners, Northern Ireland.
Mr. Parker opened by stressing that although the development of traffic management techniques should have caused a greater unity of interest between bus operators and road engineers, a wide gulf remained between civil engineers and transport operators. Only little by little, said Mr. Parker, could traffic engineering aid public transport operation, as only little by little could this new discipline effectively aid the traffic and transpcirt problem as a whole.
Outlining the basis of traffic engineering and its development, the speaker said that studies 20 years ago in the USA emphasized that the development of roads alone would not solve the problems of the larger urban areas, and this led to the concept of the "transportation study" which explored the balanced development of roads, public transport services and parking policies.
As an example of the way in which this concept had been further widened, Mr. Parker fisted the main objectives of the Belfast Transportation Study which R. Travers Morgan and Partners have been carrying out for Bei
fast Corporation and the Ministry of Development. These included examination of the transport implications of alternative land use plans; assessment of present and future traffic movement and public transport demands; assessment of the relationship between demands and the resources available, and the means by which other transport systems might meet the demands; the definition of a road plan, and the road improvement and construction priorities; the provision of guidance to bus operators on the development of services to meet future demands; advice on traffic management measures; determination of parking policies; and the aiding of an appraisal of the proposed urban motorway ring road.
To be able to plan sensibly even for the immediate future one needed to take a reasonably long view of likely future changes in passenger transport demands. In the Belfast study, for example, a "plan period" of 20 years was taken. The total demand for personal travel by car and bus in the Belfast area was expected to increase by some 76 per cent between 1966 and 1986, the number of cars owned increasing by 192 per cent. The demand for public transport was likely to decrease by 13 per cent whereas the demand for private transport was likely to rise to about 2.5 times the 1966 level.
The car can be accommodated
The benefits resulting from meeting this demand appeared to compare favourably with the cost involved. Added Mr. Parker significantly: "Thus it is by no means valid to assume, out of hand, that it is impossible or undesirable to satisfy future demands for the use of private vehicles in cities of moderate size. This is not to say that it is not desirable from the traffic engineer's viewpoint, as well the public transport operator's, to reduce demands for road space if this can be done without dissatisfaction to the travelling public as a whole."
While 65 per cent of private transport passengers and 60 per cent of public trans-, port passengers in the Belfast area 'travelled to work in the peak hour of 8-9 a.m., less than half of all the trips to work between 7 a.m. and 10 a.m. were in the peak hour itself. Thus the scope for reducing peak demands by staggering working hours was limited.
Buses: convenience before cost
A fundamental question was whether future demands for the use of private vehicles could be converted to demands for public transport. The Belfast survey showed that people did not generally consider bus and car to be competitive modes but rather served different purposes. Over half the respondents who had a choice (e,g, car owners with reasonable access to bus services) gave speed as the principal factor; one-sixth gave comfort, and only 1 in 13 gave cost.
Figures given by car owners questioned showed that they under-rated their total car running costs per mile by about half; the costs of using public transport were more immediately apparent to the public. Even so, when asked for their opinions, people criticized service twice as frequently as they criticized fares, and nearly all the favourable opinions of public transport (some 40 per cent of the total) were about the good service provided, while only a small proportion selected cheapness as a major factor. it seemed that the use of tokens and season tickets might lower passengers' perception of the costs involved in using buses and put the choice between the use of buses and cars on a more equitable basis, in so far as it was related to cost.
The motivation study in Belfast suggested that more emphasis should be placed on good service than on keeping fares down and that in future, when more bus patrons would come from households owning a car, the provision of a fast and reliable service would be more profitable to public transport operators than reducing service frequency to avoid raising fares.
The possibility of providing fast and reliable service was closely related to traffic management and traffic speeds in general, Traffic congestion meant low speeds for buses as well as for other vehicles. Commented Mr. Parker, using the phrase selected for the title Of his paper: "Convenient though it Would be for governments and public transport operators, if demands did not Change it seems that people must go, in increasing numbers. If changes are not made to cities to match changing demands people will go, elsewhere."
The needs and fashions of the future were uncertain but this must not be an argument for doing nothing or doing only that which was most expedient. Plans must be laid which answered the problems of the future as we saw them today and yet which offered reasonable scope for answering the problems of the future as we would see them tomorrow. He had in mind, in particular, the scope for reserved bus-ways. In the Belfast area the average width of all the main roads was 31ft. Few were more than 40ft wide and the network did not lend itself to closing roads or the operation of one-way streets; there was at present no reasonable scope for reserved lanes or routes for buses.
Buses lose most
Although improvement of roads was seen as a great threat to buses because it made car travel easier, the speaker pointed out that buses benefited too. He quoted a Smeed report to show how low-speed bus traffic could be the hardest hit by congestion.
There was a great potential, for public transport planning, in being able to assess how passengers might distribute themselves over a new system of bus services, but it was almost impossible to interpret the inter-action of the different demands of different passengers. For this reason R. Travers Morgan and Partners had given particular attention to a computer programme called Napro, written by IBM Germany, and designed to assess how passengers distributed themselves to the various routes and services making up a public transport system. This had been developed in connection with the Belfast study, and a similar technique, called Transitnet, was being developed by Freeman Fox, Wilbur Smith and Associates.
After explaining the information necessary in order to use the Napro technique, Mr. Parker explained that the output from the computer programme was in two parts. The first listed the stops and routes to aid checking, while the second gave:— routes taken by passengers between selected origins and destinations; analyses of riding distances, travel times, numbers of transfers; details of the way each service was used (passengers boarding and alighting); total volumes of passengers on each section of bus routes; and a graphical print-out of the utilization of services. Some of the results obtained from testing a network representing the existing Belfast transport system are shown in Tables 1 and 2 and a diagram.
There appeared to be scope for using the technique to reduce the number of transfers which passengers needed to make, while information on the distribution of riding ices of passengers was helpful in assess lenges in fare structure. Development of Japro technique marked an attempt by engineers to be in a better position to lublic transport planning.
nsportation planning, said Mr. Parker, lished the strategy to be adopted in 'sting travel problems, while traffic gement fulfilled the tactical role. Traffic gement tried to achieve the best use of ng streets and involved the expenditure latively small sums; but unless the pros were compatible with a defined :gic plan they were not in the least likely to l acceptable.
rv priorities
a many conflicting interests in the opera 9 street system, in a democratic sysof local government, led to slow pro, but needless congestion and inefficien:ffecting public transport more than anyelse—occurred because of the lack of -tance given by most cities to traffic 'gement as a distinct discipline. The first rement in cities of more than 250,000 lation was for a traffic department which antrated on traffic management to the sion of all else.
. Parker then gave examples of the traffic eer's aims in promoting traffic flow.
lile a comparison of bus and car maxicapacities showed one bus to be the alent of 15 cars, this figure was not The Napro technique showed an ayefigure of 32 people per bus; Road arch Laboratory studies had provided Js equivalents, but when vehicle size taken into account the number of pas;rs served by public transport per car unit about 10, or some six times the figure d by private transport per car unit. If ; increased in size, and their occupancy led, the "value" of buses compared to would fall to rather less than 6 to 1—still ipressive ratio.
ad passenger transport in the future, as today, would be satisfied in all but the smallest towns by a mixture of public and private transport. The changes ahead must not lead to the segregation of the interests of public transport operators and traffic engineers. The benefits of investment in road transport fully justified a positive approach to the future.
In the discussion, the delay in implementing results of transport studies was referred to by several speakers, notably Mr. E. R. L. Fitzpayne (Glasgow), Mr. R. Cox (Edinburgh) and Mr. T. L. Beagley (MoT). Mr. Fitzpayne was disturbed that after spending nearly E4rn on the Greater Glasgow Transportation Study, more dynamic action on public transport had not been taken. And in the study, most of the bus proposals were for short shuttle services from railway stations, which experience suggested were not popular.
Mr. Beagiey, referring to a comment by Mr. Parker that the only real solution to urban road problems was road pricing, said this was theoretically attractive but administratively complex and certainly some years away. He thought area traffic control, as in Glasgow, had much to offer in cutting bus journey times; he revealed that a Road Research Laboratory project would enable buses to activate a longer green or shorter red at traffic lights. He urged Ministry and operator cooperation on research.
Mr. A. F. Neal (Mol) thought today's high-capacity buses were not necessarily the best solution, and recommended a vehicle of just over 60 passenger capacity. Mr. Cox said Edinburgh had asked the MoT for a grant under the 1968 Act for a bus study, which he felt very valuable, but had been turned down flat. As to season tickets reducing passenger price perception, 8 per cent of Edinburgh's bus revenue now came from these, and this was being encouraged. Both he and Mr. L. Smith (Leicester) said average passenger capacities were of little value in comparisons; it was the road space usage of a full bus at peak periods that mattered. Mr. Smith revealed that Leicester's latest plan would discourage peak-hour car commuters by having central car parks closed at those times.
At the a.g.m. of the SR PTA the executive committee was re-elected and Mr. T. Marsden elected to it. Cllr. C. B. M. Filsell (Edinburgh) was elected vice-president and Mr. N. R. Southerland elected president.