The Hull Freight Study its implications for road haulage
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by John Darker, AMBIM LTHOUGH most professional allege operators are fully precupied with cash-flow problems own-account transport matters face implacable pressures contain or reduce costs, some ought should be directed to tenating problems in the next w years.
With road expenditures being it in every country affected by a high price of energy, the obility of lorries and coaches ill reflect, in large measure, the a increase in the number of tas on the road.
Some clues as to the official inking on the pattern of freight ovements in Britain in the next :cade may be deduced from a :cent paper presented by Mr aphen Stares, of Wilbur Smith id Associates, at the PTRC limner conference at Warwick nivers:ty. His lecture 'borethe nocuous title "Collecting data a freight and lorry movements" at it reflects, significantly, the :sponse of government.
The study undertaken by Willi' Smith and Associates in Hull as on behalf of the Transport ad Road Research Laboratory. he firm was also involved with te Hertfordshire Lorry Study.
'ypical operations
The object of the Hull exercise as to collect data which would ;present a typical day's operaon of goods vehicles in the tudy area and prepare this data r input to the TRRL computer rods model. "The model," said Ir Stares, "is designed to assess te impact of restriction on goods elvicie movements and will be le main tool used by TRRL in leir research programme using va Hull data."
TRRL Initially hoped that their might study programme would ield information on "pure 'eight" movements which could iter be translated into goods chicle movements. In practice and this does not in the least urprise me — it was found to be xtremely difficult to collect ccurate origin and deatination aformation for individual goods aovements. As an alternative, it as decided 'to collect data on vehicle movements from which goods flows could be abstracted.
At Hull, the freight vehicles studied Were of at least 15cwt carrying capacity whereas for Hertfordshire only 'hgv of over 3 tons ulw were considered. There were two mein surveys : one a Premises Survey to collect data on vehicles based inside the study area, and What was termed a cordon survey ito collect information from vehicles based outside Hull. In addition there was a postal survey, connected with the sampling base of the premises enquiry, and a manual check on goods vehicle movements picked up in the interviews.
It may sound odd for a consultant to admit publicly that "as much redundant data were collected as possible" under the heading of Vehicle Description, but the reason for this was to provide corroborative detail to offset vagueness in the replies to questions.
The survey teams checking on vehicles noted the number of axles — collected separately for the vehicle and trailer, if any. They noted that vehicles could be classified by either unladen weight, gross vehicle weight or by carrying capacity and that the lioence. value provided a useful check on unladen weight. (Although the vehicle census at road halts involved the police, the interviewers did not examine licence discs unless invited by drivers to do so. Throughout the exercise the greatest care was taken to keep on good terms with those being questioned.) There were dimensional checks of vehicles showing length, height and width and body types were specified in 14 categories, viz (i) platform ; (ii) sided (no roof) ; (iii) box body or van ; (iv) container or demountable 'body; (v) tanker ; (vi) cement mixer ; (vii) livestock transporter ; (viii) car or car body transporter ; (ix) boat carrier ; (x) low loader ; (xi) demountable open skip ; (ail) special axle vehicle ; (xiii) tractive unit only ; .(xiv) other.
It was found that the first three groups accounted for 80 per cent of all vehicles while the second two groups accounted for a further 10 per cent. Special features noted included the following: (i) articulated/drawbar trailer ; (ii) insulated/refrigerated; (iii) vehicle markings ; (iv) mechanical equipment ; (v) motive power.
Where they came from
Amongst the information sought in the questionnaire on the vehicle journey was the address of each premises where goods had 'been collected or unloaded during the day ; the type of business—this was coded from an index ; arrival and departure times ; loading and unloading information — on or off street, commodity, weight ; whether the call was urgent, regular or at a specified time; how the goods were packed on the vehicle.
All this information was collected in a log book or on a log Sheet. This was relatively easy for the premises survey since the information from the first to the last stop could be collected in sequence — presumably from documentation. But there were snags in the cordon survey where enquiries were at a midpoint through the journey.
Where a large number of stops had been made during the interview day the Information collected was summarised to show the type of establishments visited, the number of stops made, and the total weight and nature of the commodity loaded in each area. All this was allocated to a set of " synthesised " zone stops. The zone or area could include the entire town centre or perhaps a housing estate where as many as 30 different drops had been made.
The interviewers for the premises survey were all women and they were sent to selected addrestes to obtain descriptions of vehicles operated and to complete log books describing the movements of a sample of the vehicles for a typical day. At Hull 25 per cent of all vehicles based in the study area were checked.
The selection of premises ultilised the data collected in the postal survey and related to the category of firm. There were 35 categories and seven employment groups — based on numbers of employees — and five vehicle fleet sizes. The sample size chosen from each category favoured the larger firms and the larger vehicle operators over the smaller firms.
In deciding how many vehicles in each fleet to survey it was decided that a maximum of 30 vehicles would be adequate from any one firm but the sample was drawn at random from a list of all vehicles on the strength so that the " easiest " vehicles were not selected by the firm's management. .
The descriptions of vehicles were usually obtained from the transport manager or his equivalent. The difficulties in obtaining vehicle logs sometimes involved interviews with lorry drivers and Where it was found difficult to locate the relevant drivers the log 'books were given out to them for completion as part of their day's duty. In small firms the transport manager would often interview the driver and complete the log books.
People co-operated
An astonishingly high level of co-operation was 'afforded to the survey team by firms in Hull. Out of 320 firms, only 21 refused an interview and it was estimated that they operated about five per cent of the sample of vehicles examined.
Co-operation from drivers was, described as "mainly good — if the firm co-operated, So did they." In fact, the clear and official-looking log book is* thought to have materially helped to induce co-operation since it bore the insignia of the unions and the main road trans port associations (U R T U, TGWU, ETA and RHA). The General and Municipal Workers' Union was not approached since they had no drivers affected by the study but a minor bloomer was madeaby the survey organisers in omitting the National Union of Railwaymen from the list of organisations approached. NUR drivers are employed by NCL, Freightliners and the British'Transport Docks Board, and the latter body's drivers refused to co-operate.
In the cordon survey, interviewing locations were set up on the roads crossing the boundary of the study area. Interviewing occupied 16 hours per day and captured 95 per cent of all commercial traffic. Data was needed on trips to the Hull study area, in the city and from the city. It was decided to interview outbound drivers because, in a pilot survey, it was found that 20 per cent of drivers " inbound " did not know Which stops they would be making in the study area until after their first call.
How drivers talked
The pilot study had revealed something of the drivers' psychology. They liked to talk about where they were going first but could then be led back to say how they arrived in Hull earlier in the day (or on a previous day). So the order of questions was : What load are you carrying ? Where is your next stop ? Where is your load going to ? When did you arrive in Hull ? What was your load ? Where was, your last stop before Hull? Where did that load come from ? What stops did you make in ?
The survey team thought that lorry drivers might try to dodge interview stations by using alternative routes. To check this, a number of vehicle counts were made before and during the survey on adjacent roads but no significant diversions of goods vehicles were found. Perhaps not surprisingly, many private cars appeared to divert, though they were not subject to interviewing Only externally based vehicles were needed for interviewing at the roadside checks but it was not possible to tell the vehicle base as a vehicle approached the interview station. "Rather than letting internally based vehicles through after just one question, several questions were asked so that word did not get around transport cafes that a simple .answer to the first question would permit a quick passage through the interview station."
Immense efforts were made by the consultants to ensure that the statistical picture revealed by the Hull survey was valid. They found that under-reporting was much more prevalent with small vehicles ; most of the heavy vehicle journeys were revealed. What everyone concerned with goods vehicle operation will want to know must await the processing of this information by TRRL's computer goods model.