Column - July 2015
Increasing rail and water freight will cut road congestion
Getting more freight onto rail and water could significantly reduce road traffic and congestion, according to research commissioned by Campaign for Better Transport. 1 While the Government is committed to investing significant funds in the railways and in rail freight in particular it has played down the potential benefits of the transfer from lorries to sustainable methods by only looking at national averages across all strategic roads.
However, this new research also looked at specific routes which typically tend to be more congested because of more long-distance HGV traffic, particularly to ports. HGV traffic overall could fall by 21 per cent, and congestion could fall by 15-25 per cent were rail and water freight both to increase by 50 per cent on these routes.
Overall it is clear that there are a group of corridors which have double the average HGV flows and a higher than average propensity for transfer. A 50 per cent increase in rail alone could reduce HGV traffic on busier roads by 12 per cent and road congestion by 9-12 per cent.
This piece of research addresses a key issue for freight transport and road capacity: The key to understanding this issue is to separate out the national average picture across all road types from the impact on the most heavily used roads where congestion occurs. In addition, it is important to separate out the activity of the largest goods vehicles from those which are undertaking local deliveries and are less likely to be replaced by modes such as rail or water.
The Government statement, maintaining that increasing rail freight by 50 per cent would only be equivalent to a reduction of around 7 per cent in road freight, only looks at national averages and therefore needs to take into account the following to get a true picture of the potential to reduce road congestion:-
- that some parts of road network have more long distance HGV traffic which could be carried by rail
- National figures include small HGVs which do not compete with rail. It did not separate out the activity of the largest goods vehicles from those which are undertaking local deliveries and are less likely to be replaced by modes such as rail or water.
- that HGVs occupy considerably more road space than cars (have a high passenger car unit pcu value),also need longer braking distances and slower to manoeuvre and therefore cause more road congestion
- In congested conditions each single per cent increase in traffic causes several percentage increase in congestion. In fact, Department for Transport figures state that a modest decrease in traffic of around 2%, results in congestion falling by 10%. This is backed by the fact that DfT figures show that on congested parts of the network, congestion could be three to four times the percentage reduction in overall traffic levels, using a simple low congestion impact multiplier of 3-4.
- the average figures disguise the more significant impacts where HGVs are a higher proportion of traffic
- the impact of additional traffic in already congested conditions is far greater than a simple increase in pcu or vehicle kilometres suggest – it rises exponentially.
Some useful figures are contained in the report. The average haul for road was 94 kms, 195 kms for rail and 319 kms for coastal shipping. HGV traffic is 10.2 on the strategic network.
Growth is predicted for the strategic network where HGVs are a higher proportion of traffic so reducing them would have greater impact. This research demonstrates the potential of rail freight to relieve specific corridors where road schemes are planned.
Freight on Rail believes that the Government should take account in its forecasting and modelling and in its policy and spending the potential to shift HGV traffic to rail and water and the congestion, safety and pollution benefits of doing so.
1. Research - Potential reductions in congestion on the strategic road network from alternatives to HGV use. Metropolitan Transport Research Unit. April 2015
2. The National Networks Policy Statement contains the following statement:
"In general, the nature of some journeys on the Strategic Road Network means that there will tend to be less scope for the use of alternative transport modes…. If freight carried by rail was to increase by 50% (in terms of tonne kilometres) this would only be equivalent to a reduction of around 7% in goods carried by road."