A1 Leeming to Barton five-year post-opening project evaluation (POPE)
A summary of our evaluation of this major road project against its objectives five years after opening.
For more details of our evaluation methods, please refer to the Major Enhancements evaluation approach.
For information on limitations, contextual factors and data constraints that may affect project performance assessment in POPES, see our POPE factsheet.
Glossary of terms used in POPE evaluations.
Evaluation summary
Five years after opening, the A1 Leeming to Barton project successfully added capacity and reduced congestion along this strategically important route. The project had improved safety by reducing the frequency of collisions and the severity of accidents. Our analysis also showed that measures implemented to manage landscape and biodiversity impacts were continuing to establish and improve. Our evaluation identified issues with some surface water drainage features, which are now being addressed through a new drainage renewals programme. This should support the delivery of long-term drainage benefits.
Data quality issues had affected some of our analysis meaning we were unable to quantity some of the benefits including for journeys times and value for money. However, overall, the analysis suggested that the project had a positive impact on customer journeys.
Overview of objectives
The project was developed to meet a number of specific objectives. The table below assesses the extent to which these objectives have been achieved based on the evidence collected through our evaluation.
Overall, the evidence shows the project has achieved its core objectives and continues to deliver positive outcomes for road users.
| Objective | Result |
|---|---|
| Reduced the current level of accidents | The number of personal injury collisions had reduced along with the collision rate and severity of those collisions. |
| Reduced congestion | The extra capacity and the new local access road had reduced congestion. |
| Enhanced journey times | Data limitations meant we were unable to quantify journey time improvements, but our analysis indicated the project had a positive impact on customer journeys. |
| Minimise the impact of the project on the environment | The impacts of the project had broadly been minimised as expected. However, there is a risk that drainage benefits will not be achieved if improvements to the maintenance regime are not implemented. |
Project outcomes compared to forecasts
Appraisal forecasts set out the impacts anticipated during project development. The table below compares these forecasts with observed outcomes to assess the extent to which expectations have been met.
Our evaluation has been affected by the availability of the underlying appraisal information and baseline traffic data. Some of the appraisal information related to the original larger A1 Dishforth to Barton project, making attribution and quantification of some of the project benefits difficult.
The project has broadly achieved its intended outcomes, however there are some differences between:
- what was expected at appraisal
- what has been observed five years after opening
The tables below compares forecast and observed outcomes across each evaluation theme.
Customer journeys
| Sub-area | Outcome vs forecast | Key notes |
|---|---|---|
| Traffic growth | Mixed outcomes | Comparisons were limited due to the availability of data. Forecasts may have overestimated growth along the A1. Traffic had shifted from the local roads to the A1 although not to the extent forecast. |
| Journey times and journey time reliability | Unable to evaluate | Congestion had reduced but it was not possible to quantify journey time and reliability changes. |
Safety
| Sub-area | Outcome vs forecast | Key notes |
|---|---|---|
| Safety | In line with forecast | Fewer collisions and casualties. |
Environment
| Sub-area | Outcome vs forecast | Key notes |
|---|---|---|
| Noise | Broadly in line with forecast | Mitigation had been provided and where traffic data was available, changes were consistent with those predicted. |
| Air quality | Broadly in line with forecast | Where traffic data was available, changes were consistent with those predicted. |
| Greenhouse gases | Better than forecast | Based on the limited traffic data available, emissions were likely to be lower than predicted. |
| Landscape | In line with forecast | As expected, new landscape plots were on track to deliver design year outcomes. |
| Townscape | In line with forecast | As expected, new planting was on track to deliver design year outcomes. |
| Heritage of historic resource | In line with forecast | Archaeological investigations were undertaken and mitigation for the setting of listed buildings provided. |
| Biodiversity | In line with forecast | As expected, new mitigation was on track to deliver design year outcomes. |
| Water environment | Worse than forecast | New drainage mitigation was overgrown and there is a risk that design year outcomes won’t be met if maintenance is not improved. |
Value for money
| Sub-area | Outcome vs forecast | Key notes |
|---|---|---|
| Value for money | Unable to evaluate | We have been unable to quantify the benefits so unable to confirm the high value for money predicted. The evidence however does suggest there was a positive impact on road users. |
Why do some outcomes differ from the original forecasts?
Evaluation compares what actually happened with what was expected during appraisal. Differences between forecast and observed outcomes are influenced by a combination of factors.
The age and the decision to split the project into two phases and subsequently the decisions to pause and then restart the project contributed to missing appraisal information and gaps in the baseline traffic data. These issues meant we were unable to quantify journey time and journey time reliability benefits and this also affected our ability evaluate value for money accurately.
Continuing to maximise benefits
The project has achieved many of its intended outcomes. Our evaluation did identify issues with the drainage systems. A new drainage renewals programme has since been implemented which should ensure long term drainage benefits are met.
Project overview
The A1 is a strategic route in England linking London with the Midlands and the Northeast. The A1 Leeming to Barton project is a 12-mile section in North Yorkshire running from junction 51 in the south through the Scotch Corner junction with the A66 and finishing at junction 56 Barton in the north.
The project was originally part of a larger improvement covering the A1 from Dishforth to Barton. A government decision was taken to deliver the improvement in two phases, Phase one Dishforth to Leeming followed by Phase two Leeming to Barton. Phase one opened in 2012, but Phase two was paused following a Government Spending Review. Phase two re-entered the roads programme and construction started in 2014 with the project opening in 2018.
The project involved:
- upgrade of the original dual two-lane carriageway to a dual three lane motorway between Leeming and Barton junctions
- new grade separated junction at junction 52 Catterick and capacity enhancements at junction 53 Scotch Corner
- a new local access road to run parallel to the A1 to meet demand for local and non-motorway traffic
Location map
Why the project was needed
Prior to the upgrade, this section of the A1 regularly suffered from congestion due to high volumes of HGVs and slow moving local and farm traffic. Substandard junctions also led to safety concerns.
The project was designed to increase capacity along the road by adding a lane in each direction and improving the junctions along the route. A new local access road was also created running parallel to the A1 to enable both local and strategic traffic to complete their journeys without affecting each other.
