New roads increased traffic and greenhouse gases, damaged wildlife and designated environmental sites and did not produce the economic benefits proponents used to justify their construction, analysis of data from England's highways authority has found.
The research, by consultants Transport for Quality of Life Community Interest Company (TfLQ) for the Campaign to Protect Rural England (CPRE), examined official data from Highways England for 86 completed road schemes.
The effects of schemes were measured using Highways England’s Post Opening Project Evaluation (POPE) data one to five years after they opened. Roads completed between 13 and 20 years ago were also scrutinised to assess long-term impacts. These were: the A34 Newbury bypass; M65 Blackburn Southern bypass; and dual-carriage ways on the A46 between Newark and Lincoln and A120 between Stansted and Braintree dualling.
The analysis found that traffic increased more on new roads than background traffic in the surrounding area. Roads completed eight to 20 years ago experienced a 47% increase in traffic, and more than doubled on the M65 Blackburn Southern bypass.
All new schemes put pressure on adjoining roads, and reductions in journey times were found to be negligible. During peak time, the median time saved was 90 seconds, while journeys were 60 seconds shorter during off-peak periods.
More than half of the road schemes analysed harmed protected landscapes and designated sites, including national parks, areas of outstanding natural beauty, ancient woodland and historic places.
The new roads also increased greenhouse gas emissions, the research found. Fifty-four road schemes opened between 2002 and 2010 and cumulative emissions from them reached 8 MtCO2 in 2015.
TfLQ said its estimates for emissions were conservative due to the complexity of comparing what would have happened to traffic levels without the scheme.
Biodiversity was damaged in a large number of cases analysed. This was due to various factors, including route choices, failure to identify or implement mitigation measures, lack of maintenance or vandalism. For example, lapwings overwintered in an area that was destroyed by the construction of the M40 J15 Longbridge roundabout. No mitigation was planned for the loss of habitat, and money requested by the local authority to contribute to the cost of new habitat did not materialise. Lapwings have now been wiped out in the area, the research found.
The great crested newt population near the A6 Alvaston improvement scheme declined from around 300 to less than ten. The population of the protected species was underestimated, resulting in replacement ponds being too small. The new ponds were also badly designed and dried out several times, the report states.
The government has pledged to increase annual spending on the strategic road network from £1bn in 2016 to £3bn by 2020/21. Highways England is expected to publish a consultation this month on potential schemes.
Ralph Smyth, head of infrastructure and legal at the CPRE, said: ‘This landmark research shows that any benefits from road building are far smaller than thought but the harm much worse.’
Instead of giving three times more funding to the road building programme, the government should invest in a strategy that puts quality of life ahead of the car, he said. This should include reopening old rail lines, harnessing new technology to make more efficient use of road space and promoting new housing on brownfield sites closer to jobs and services.
‘Building ever bigger roads should be the last resort, not the default choice,’ he added.
Steve Gooding, director of motoring organisation the RAC Foundation, said: ‘This report highlights some home truths. We are a congested island with a growing population and expanding economy. Few of us battle daily congestion on the roads and railways through choice but necessity; because we need to get to work, get the children to school or get to the shops.’
These essential journeys could be made shorter and easier if land use planning and transport are better aligned, closely linking housing, business and retail development, he said.
He added that the Highways England programme is mainly about adding capacity to already congested stretches of road, rather than contemplating entirely new roads.
‘Where new routes are on the table, for example the badly needed new Lower Thames Crossing, we would expect their designers to take on board the lessons from this report,’ he added.