M4 forecasts flawed, expert tells AMs

M4 forecasts flawed, expert tells AMs

M4 forecasts flawed, expert tells AMs

First published in News

FORECASTS for growth in traffic on the M4 are too high, a transport expert told AMs yesterday.

Prof Phil Goodwin, professor of transport at the University of the West of England, criticised work on the M4 consultation saying it was simply not credible to presume traffic would continue to grow forever unchallenged.

He said elaborate coloured graphs in a report on the project would amount to “colouring in” if forecasts are unreliable.

The transport professor was speaking at an inquiry by the Assembly’s environment and sustainability committee, which is looking into plans for the M4 Relief Road.

The consultation paper for the M4 Relief Road says that by 2035 the motorway around Newport will be heavily congested, and argues a new motorway could help to significantly reduce such problems.

One graph suggests that forecast trips in Newport and South East Wales will grow continuously from now until 2030.

“I think the growth forecasts are wrong, I think they are too high,” Prof Goodwin argued.

“We will not see traffic growth rates in the next ten or 50 years’ analogous to traffic growth rates we saw during the 1980s. I think that is a transition which took place not recently, but in the mid-1990s.”

Prof Goodwin said: “(The appraisal) is completely dependent on the confidence you place in the Department for Transport regional trip rate forecast and on the implication that traffic growth in future will follow this track for the next quarter of a century and a beyond.

“Actually, the levelling off of traffic growth started ten years before the recession. It’s simply not credible to presume a single future of continued uninterrupted traffic growth forever”

He said the world had changed and that “planning now has to be robust for any levels of traffic growth – or none at all, or even a decline – on low traffic roads, not only continued uninterrupted fast growth into the future.”

Prof Goodwin argued that “policies and projects which are geared to recognising or achieving lower road traffic growth, and are more robust to grievous forecasting errors, are likely to perform very much better than implied in the rather elaborate coloured pictures in the report.”

The West Country-based expert said he had “great pleasure” in looking at the coloured graphs in the report, “but if the forecasts are unreliable (they) are basically just colouring in.”

He held out that it was a possibility the forecast could come to pass, but said if it did the planned expansion of road capacity being considered is not nearly enough to improve traffic conditions.

Comments (9)

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11:46am Thu 3 Apr 14

davidcp says...

Never mind growth, it's too full NOW!
Never mind growth, it's too full NOW! davidcp
  • Score: 10

12:16pm Thu 3 Apr 14

throwy1 says...

About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?
About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail? throwy1
  • Score: 5

12:52pm Thu 3 Apr 14

StaceyJ1986 says...

throwy1 wrote:
About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?
Are you aware that nearly all towns and rural areas in the UK DO NOT have rail access. You are making yourself sound very stupid here as if you have 1 small shop in a village that will require about 2 articulated lorries a week to keep stocked up. Are you suggesting that we clog up the roads more with small vans (we all know how most of them drive)
[quote][p][bold]throwy1[/bold] wrote: About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?[/p][/quote]Are you aware that nearly all towns and rural areas in the UK DO NOT have rail access. You are making yourself sound very stupid here as if you have 1 small shop in a village that will require about 2 articulated lorries a week to keep stocked up. Are you suggesting that we clog up the roads more with small vans (we all know how most of them drive) StaceyJ1986
  • Score: 1

1:12pm Thu 3 Apr 14

Sometimes says...

Of course this is only ONE experts opinion, perhaps they should try asking all the experts who use it every day and they may find they have a different opinion to this expert. Is this the same expert that suggested using the SDR as the alternative route or was that another expert? Again probably an expert who has never used the roads in question to get to their place of employment so they can then pay their taxes.
Of course this is only ONE experts opinion, perhaps they should try asking all the experts who use it every day and they may find they have a different opinion to this expert. Is this the same expert that suggested using the SDR as the alternative route or was that another expert? Again probably an expert who has never used the roads in question to get to their place of employment so they can then pay their taxes. Sometimes
  • Score: 4

1:41pm Thu 3 Apr 14

jerymp says...

throwy1 wrote:
About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?
You are right about the dangerous driving but obviously it would be impossible to deliver everything by rail.
As to the standard of driving responsible for most of the accidents and delays especially around Newport a far cheaper alternative would be greater police presence to enforce lane discipline and spacing.
It's amazing how the sight of a police car improves driving.
[quote][p][bold]throwy1[/bold] wrote: About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?[/p][/quote]You are right about the dangerous driving but obviously it would be impossible to deliver everything by rail. As to the standard of driving responsible for most of the accidents and delays especially around Newport a far cheaper alternative would be greater police presence to enforce lane discipline and spacing. It's amazing how the sight of a police car improves driving. jerymp
  • Score: 0

4:16pm Thu 3 Apr 14

keithbob says...

throwy1 wrote:
About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?
Being an ex trucker myself,stupid comments like this amaze me.ever seen a train travelling down a high street or to an industrial/retail park?.throwy.how do you think your bed, armchair or tv your watching was delivered.by helicopter?.the motorway was designed mainly for the purpose of taking heavy traffic off the A and B roads,then delivered to the retail parks,they were also restricted to 56 mph.while the white van man or cars who often break the speed limits are the worst danger!.
[quote][p][bold]throwy1[/bold] wrote: About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?[/p][/quote]Being an ex trucker myself,stupid comments like this amaze me.ever seen a train travelling down a high street or to an industrial/retail park?.throwy.how do you think your bed, armchair or tv your watching was delivered.by helicopter?.the motorway was designed mainly for the purpose of taking heavy traffic off the A and B roads,then delivered to the retail parks,they were also restricted to 56 mph.while the white van man or cars who often break the speed limits are the worst danger!. keithbob
  • Score: 2

6:43pm Thu 3 Apr 14

Bobevans says...

StaceyJ1986 wrote:
throwy1 wrote:
About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?
Are you aware that nearly all towns and rural areas in the UK DO NOT have rail access. You are making yourself sound very stupid here as if you have 1 small shop in a village that will require about 2 articulated lorries a week to keep stocked up. Are you suggesting that we clog up the roads more with small vans (we all know how most of them drive)
Rail is only really usefull for bulk point to point freight and there is not a lot of that
[quote][p][bold]StaceyJ1986[/bold] wrote: [quote][p][bold]throwy1[/bold] wrote: About 4 times a year I make a journey to the N.W. of England travelling in the very early hours. It is interesting to sere how many articulated lorries (18 wheelers) are using the motorway system, all being driven at about 56mph and about 5 foot if you are lucky between them. Firstly this is extremely dangerous driving and secondly why can't this freight be transported by Rail?[/p][/quote]Are you aware that nearly all towns and rural areas in the UK DO NOT have rail access. You are making yourself sound very stupid here as if you have 1 small shop in a village that will require about 2 articulated lorries a week to keep stocked up. Are you suggesting that we clog up the roads more with small vans (we all know how most of them drive)[/p][/quote]Rail is only really usefull for bulk point to point freight and there is not a lot of that Bobevans
  • Score: 2

6:45pm Thu 3 Apr 14

Bobevans says...

First the M4 around Newport is already congested. Second the UK population is increasing by at least 500,000 a year and currently we are in the midst of a recession. This suggest that the M$ will see significant traffic growth
First the M4 around Newport is already congested. Second the UK population is increasing by at least 500,000 a year and currently we are in the midst of a recession. This suggest that the M$ will see significant traffic growth Bobevans
  • Score: 2

7:09pm Thu 3 Apr 14

Limestonecowboy says...

We don't wamt more experts a new M4 is required just got on with it !
We don't wamt more experts a new M4 is required just got on with it ! Limestonecowboy
  • Score: 3

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