Traffic Volumes In 1980 Too Great For Roads

Press, Volume C, Issue 29665, 8 November 1961, Page 12

Traffic Volumes In 1980 Too Great For Roads

Christchurch’s roads would be inadequate to meet the expected growth of traffic volume up to 1980, said Miss N. Northcroft, the Regional Planner, yesterday when she presented the first major report in preparation of a master transportation plan to the Christchurch Regional Planning Authority. Miss Northcroft’s report set out the traffic volumes expected in 1980, when it was predicted that there would be a big increase in the number of vehicles, and discussed in general terms possible solutions.

Miss Northcroft said that immediate expense could be obviated by imposing parking and stopping restrictions, leaving the roads as they were; but made it clear that she believed that the sort of traffic conditions which must develop through congestion, wear and tear and delays would produce their own financial and social costs. When traffic increased beyond the volume of 20,000 vehicles a street a day, the roads would be full and the new route would have to be built anyway, she said.

When she produced a map showing tiie traffic volumes expected in about 20 years, Miss NorthcroPt said it represented a critical stage in the development of the master transportation plan. It marked the point of transition from presentation of the problems to be solved to consideration of the ways in which the problems might be solved.

Looking at the expected increase in motor-vehicle ownership, Miss Northcraft said that in 1959 there were 06,723 vehicles registered in Christchurch: in 20 years they were expected to increase by 129 per cent, to For the same period, oars were expected to increase by 136 per cent, from 53,117 to 125,600. Of the forecast period. Miss Northcroft said that, over all, the traffic calculated to be generated by all the different parts of the city would add up to the total traffic that could be expected in 1980, when the population had increased from 196,000 to 311,000 and those in employment from 70,000 to 114,000. However, some parts of Christchurch would develop ahead of others, and the traffic generation would accompany it.

Examining the main, assumption of the most direct and convenient route, Miss Northcnoft said it put a heavy volume of traffic on some streets when compared with others. The map showed that at Colombo street, just south of the railway line, the 1980 traffic would be 32,750 vehicles a day, while the two or three streets to the west carried between them only 11,000. Colombo street could not possibly carry 32,000 vehicles—today the figure was 13,000—but the answer was not immediately to suggest that it be widened or a motorway provided. First, another assignment of the area could be made to see to what extent some of the Colombo street traffic could be drawn off by re-.

routing, with reasonable convenience still, to other nearby streets.

"The real problem comes in deciding how best to meet the deficiency that has been revealed,” Miss Northcroft continued, and she mentioned Lincoln road and Waltham road, also just south of the railway line. Today these roads each carried about 10,000 vehicles but were expected in 1980 to carry 23.000. so it appeared that relief would have to be found. But they were streets which might be considered for the rerouting of some other traffic. Buflt-np Area Taking the built-up area as a whole, Miss Northcroft said the number of daily journeys of half a mile or more made by- motor-vehicles was 421,000 in 1959. By 1980 the number would have increased by 141 per cent to 1,015,000. Changes in the distribution of trips within the built-up area were also going to have some effect on the sort of pattern or roadtag network needed in the future. Although a substantial increase of 107 per cent, was expected in tiie number of trips in and out of the central business area, the proportional increase in the rest of the built-up area would be much greater. "This means that though by far the most dominant single generator of traffic in 1980 will be the city centre, we must expect and be prepared to meet a greater amount of suburban traffic than we have had so far,” she said.

The volumes of traffic on tile radial routes could be expected to be maintained over longer distances from the centre outward, so that not only would traffic volumes be higher, but they would persist over greater lengths of the roads. External traffic—that which moves in and out of Christchurch from outside—was

also expected to show a substantial increase of 164 percent., she said. In 1959. 20,000 vehicles moved in and out of Christchurch each day. In 1980 the figure was expected to be 69,000. Though that figure represented a large amount of traffic it wss only 7 per cent, of the mtilion-odd trips comprising the traffic within the built-up area.

Of all tiie traffic coming in from outside, nearly onethird was expected to be destined for the area within the belts, and the centre was expected, therefore to remain the largest single generator or attraction for outside traffic. In spite of that. 22,000 vehicles coming right Into the centre from all directions was not a very large number. Miss Northcroft said. That

was the sort of information that should be kept in mind when motorways were being considered. Motorways

"I want to make it quite clear that I am not, at this moment, suggesting that motorways right into the heart of the city may be neither needed nor warranted,” she said. “However,. I am indicating that if motorways are to be built then they will have to be so located that they serve urban traffic as well as outside traffic.” Miss Northcroft said that far too much emphasis bad been given to the needs of through traffic vehicles which passed right through Christchurch without stopping—and a lot of nonsense talked about it. In 1959, of the 26,000 vehicles that came in and out of Christchurch each day from outside, only 700 of them, representing less than 3 per cent., passed through Christchurch without stopping somewhere within the built-up area, and in 1980 it was not expected that the proportion would be much different. Of the 69,000 vehicles coming in and out of Christchurch each day in 1980 fewer than 2000 would want to go right through. “Is this the sort of volume of traffic for which we should be thinking of building expensive by-passes?” she said. “Even if we are wrong about the number, we would have to be very wrong indeed before there can be any justification for thinking in terms of bypasses. The answer for through traffic is more likely to be found in the development of internal routes which, though designed primarily for urban traffic, will be reasonably convenient for through traffic and enable it. to pass across the town without necessarily going through the centre.” Carlton Mill Corner

To give a picture of the actual traffic conditions that could be expected to develop on the roads. Miss Northcroft spoke first of the “north belt,” embracing Carlton Mill road to Colombo-Man-chester street, but excluding Springfield road. By adding the traffic there was a total volume of 60.750 vehicles. Spread equally over the three routes, assuming that that could be done, there was a volume of about 20,000 vehicles apiece. “May I ask you to visualise what conditions would be like on Carlton Mill road. Papanui road, and the Cranford street route if each were to carry 20,000 vehicles a day, when it is realised that today Carlton Mill road carries a daily volume of 6000. Papanui road 13,000, and the Cranford street route at the belt 11,000,” she said. “I have no doubt that a traffic volume of 20,000 could be squeezed through on these roads, but at a cost in delays and wear and tear. There would be traffic jam condiditions, for already it is becoming increasingly difficult to get on to or across Papanui road from side streets. “What is the position going to be at Carlton Mill corner when we have something like 40,000 vehicles a day passing through the intersection, compared with 18,000 at the present time? I would suggest that tiiis is one of the part! where the traffic volumes shown on the map will develop before 1980, as the roads concerned tap the fast-growing areas to the north and north-west, so that in this sector it may be that time is running out" A similar sort of situation, only a little worse, could be found in the west and southwest. If Riecarton, Blenheim and Lincoln roads were added there was a total volume at the belts of just over 78.000. Divided equally, it produced a volume of 26,000. Blenheim road might be able to handle this, but the other two certainly could not. “And what ia the Moorhouse avenue-Lineoln road intersection going to be like?” she asked. Solutions Examining two possible solutions, Miss Northcroft said one was to leave the roads as they were, apply parking and stopping restrictions increasingly throughout most of their l«igth. and push the traffic through at an ever-decreasing speed and an ever-increasing state of congestion and frustration. The other was to build a new route in such a position that it would lift sufficient traffic off existing roads to reduce the traffic volumes to something like 10.000 vehicles, that wm, not unlike what they were today. “The second method will mean considerable initial expense and disturbance to property, but the disturbance will not be a growing and continuing one,” she said. “It will also provide, for those

using the new route, very good travelling condition# and, for the existing roads, conditions which wHJ be at

least as good as they are today.” The nearer traffic volumes approached the point at which there were prolonged delays, the more rapidly the situation deteriorated, so it was possible to be lulled into a sense of false security, Miss Northcroft said. Conditions might not seem good, but bearable, and then suddenly they became intolerable. The same standard of service was not required on all types of roads. At one extreme was the rural highspeed highway, at the other the busy city street of the central business district But if business of the town was to be carried on expeditiously and efficiently, she suggested that the standard of service on the main radial roads and cross-town routes should be of a fairly high order.

Miss Northcroft concluded by saying that some ideas for meeting the 1980 traffic situation were already on ■paper, and it would not be long before the first proposals would be submitted. "I can understand that most people are impatient to see the plans, but an appreciation of the situation is the first essential," she said. “Shocking"

'“The implications which arise are quite shocking and the master transportation plan is going to shock the community to the core,” said the chairman (Mr E. J. Bradshaw). “Our first task is to satisfy ourselves that we understand the basis on which the plan is being built, the problems that arise, and the necessity for the solutions which will be suggested."

It would be easy to say that the basis was on estimated figures which might prove wrong, said Mr Bradshaw, but the authority had seen enough of the work presented by its officers since its inception to have complete confidence in anything submitted. If anything, the figures were probably conservative.

Though it would be easy to take the line of least resistance and say that the reading equid be patched for a year or two, the authority would be failing in its duty if it took that line, Mr Bradshaw said. In major works, it took about 10 years to get a plan from paper to the stage of completion. “Fabulous" Cost

“The cost is going to be fabulous,” Mr Bradshaw said. “There will be some considerable assistance, I hope, from the National Roads Board, but whatever it is the cost to the citizens of the region will be very considerable.”

Early consideration should be given to the sharing of the cost—whether it should be met territorially or regionally— he said, and he suggested that a regional proportion would be the fairest way of meeting it. The authority's transport advisory committee will consider the report before a special meeting of the authority discusses it.