It is pretty widely understood, apparently outside political circles, that if you build roads you get more traffic.
A report commissioned by the Campaign to Protect Rural England looked into the effects of major road projects and unsurprisingly found that yes, you do indeed get more traffic.
CPRE commissioned consultants Transport for Quality of Life Community Interest Company (TfLQ) to examines the impacts of road schemes on traffic, the environment, the economy, road safety and land use.
Source: The Impact of Road Projects in England – Campaign to Protect Rural England
This is particularly pertinent to us here in South Wales, with much discussion ongoing regarding the “Newport” problem. One rather controversial idea floating about is to spend nigh on a billion pounds building a motorway south of the current M4 motorway. However, the M4 relief road is just one of many expensive road projects that may turn out to be folly.
The executive summary is pretty damning in this report. In terms of traffic generation it found that:
Evidence from 13 road schemes (nine randomly selected from all available POPEs, across all English regions, and the four case study schemes) is consistent with the conclusion that road schemes generate traffic. Average increases over the short run (3-7 years; seven schemes) were +7%. Average increases over the long run (8-20 years; six schemes) were +47%.
However, it also goes on to talk about the environmental and economic impacts.
Evidence from the four case study schemes suggests that the impacts of road schemes on landscape and biodiversity are long-lasting.
It also noted the inevitable increase in carbon emissions. However, the kicker here is that any talk of “economic benefits” in connection with these new road schemes are on shaky ground.
Of 25 road schemes justified on the basis that they would benefit the local economy, only five had any evidence of any economic effects. Even for these five, the economic effects may have arisen from changes incidental to the road scheme, or involved development in an inappropriate location, or involved changes that were as likely to suck money out of the local area as to bring it in.
Of course the report goes on to recommend the usual less toxic interventions, such as investing in rail & active travel but this is not at all surprising. It’s an argument that many people have been making until they turn blue in the face, but as a society we persist in throwing millions, if not billions into new roads.
It’s hard not to get frustrated when, despite people seemingly aware of the right answer, vast amounts of money is spent willingly on the wrong one. We know why and we’ve talked about it at length in our Wants vs Needs post and no doubt on other occasions too. We suspect we will soon start to turn blue in the face…
The Welsh Government’s statement of case attempts to deny this:
2.3.2 New roads increase capacity, however it is not capacity that affects the demand for
travel, but the ease of travel provided. For instance where roads are un-congested,
adding additional capacity has very little effect on travel times or travel costs, so that
travel demands are barely affected.
2.3.4 There may be instances in which entirely new additional traffic arises from a switch
from public transport or in terms of new trips arising from the change in travel costs
on the road network. However, frequency changes do not arise for all trip purposes
and are generally small by nature. In particular trip frequency changes do not occur
for commuting trips, but may occur for instance for leisure/shopping trips, which are
likely to occur outside of the peak periods.
(From statement of case (part 2 and 3) document available here:
It sounds as though their traffic forecasts do not reflect reality, in which case their forecasts for CO2, NOx etc. etc. are going to be too low as well. I’m not sure what can be done at this stage, but surely worth writing to our AMs?
Yes, writing to your AM would be the first step.