17. The Government calculates congestion by comparing
actual travel speeds with the 'free flow' speeds that would apply
at very low levels of traffic. It converts that comparison of
real and maximum speeds into the 'delay' encountered by the average
vehicle travelling one kilometre. The effect of the Plan is expressed
as a percentage reduction (or increase) in congestion, defined
in that way, for different types of road and area compared with
levels in 2000. The
Plan states that "in urban areas, the biggest concerns are
traffic congestion and the cost, convenience and reliability of
public transport" and that, on the strategic road network,
"about 7% of the network currently suffers heavy peak and
occasional non-peak congestion, and a further 13% suffers heavy
congestion on at least half the days in the year".
Table 1 shows the Government's estimates of the changes in road
traffic levels and congestion with and without the Plan.
(% CHANGE ON
||Inter-urban Trunk Roads
||Conurbations and Large Urban
Source: Transport 2010: The Background Analysis, p27.
Two different concerns were raised about the congestion measure:
(a) are the congestion targets appropriate and achievable;
(b) did the focus on congestion bias the Plan at the expense
of other objectives including social inclusion and safety?
18. The Automobile Association described the congestion targets
as desirable and achievable but modest.
The Freight Transport Association was reassured that there was
the "prospect of things actually improving rather than just
not getting worse".
However, it told the Sub-Committee that journey reliability was
the most important factor to its members and that levels of congestion
per se were not always a problem.
The Highways Agency told the Sub-Committee that it would target
congestion hot spots and that there would be significant improvements
in flows through particular parts of the network.
19. There is widespread dissatisfaction with the measure of congestion
currently adopted. The Government acknowledged in January 2000
that its congestion indicator needed further work and pledged
to investigate it further.
The Minister for Transport, Mr John Spellar, told the Sub-Committee's
inquiry into the Department's 2001 Annual Report that the congestion
measure was only "possibly reliable"
and that "whether it is satisfactory as to how the average
motorist or even, indeed, the average pedestrian perceives congestion
is more open to question".
In contrast, Mr Willy Rickett, Director General of Transport Strategy,
Roads, Local and Maritime Transport at the Department, told the
Sub-Committee during this inquiry that congestion, as defined,
was measurable, forecastable and "bears some relationship
to what road users say they think congestion is".
20. Travel time was suggested as the most useful indicator of
congestion because congestion is of significance to travellers
only as a result of its impact on travel time and costs.
Research by Professor Phil Goodwin for the Council for the Protection
of Rural England has shown that the Department's definition of
congestion had the effect of exaggerating very small expected
changes in the speed of travel, and argued that the Department's
own figures show that "for all classes of roads, the traveller's
experience of improvement or deterioration in average speeds from
any one year to the next will be invisibly small compared with
the normal unpredictable variations in the conditions of daily
Department notes that, although travel times on the trunk road
network will be on average only 0.6 seconds per kilometre faster
than today, they would rise by 1.7 seconds per kilometre without
the measures in the Plan.
21. The congestion measure is poorly understood and was considered
inappropriate. The Greater Manchester Passenger Transport Executive
believes that congestion is a "very difficult concept".
The Construction Products Association found the lack of clarity
on the congestion measure "alarming" and was concerned
that there are "no intermediate targets to allow progress
to be monitored".
The Freight Transport Association expressed concern about the
ability of the road network to recover from traffic incidents
that create ad-hoc delays. It suggested the use of an indicator
of network resilience, a measure of the time taken for the network
to resume normal conditions after any incident.
The Highways Agency is currently working on new measures to reduce
the time taken to clear major incidents on the strategic road
network. The Freight
Transport Association believed that the forecast 26 per cent increase
in traffic on the strategic road network would reduce the ability
of the network to recover from accidents.
22. The Plan has been built around an indicator of congestion
that is, by the Department's own admission, less than satisfactory.
It is not clear what purpose the congestion measure serves except
to multiply almost insignificant journey time savings into comforting
numbers that the traveller does not understand. The Plan has been
designed around the need to reduce congestion and pollution. If
the congestion measure used is inadequate then it is highly likely
that the projects designed and constructed to meet the congestion
target will reflect those inadequacies, and monitoring may be
misleading. A better indicator would lead to better policies and
better monitoring. The Department must re-examine the congestion
measure on which much of the Plan is based. The Plan must make
explicit the changes that it will make to journey times and the
day-to-day variability of journey times. This is the information
required by business and the travelling public. It is also imperative
that the Plan sets yearly or intermediate targets for travel conditions
so that progress towards the targets for 2010 can be assessed.
23. The 10 Year Plan sets out the pollution problems currently
faced by the United Kingdom. Carbon dioxide is the most significant
of the greenhouse gases causing climate change. Carbon dioxide
emissions from the transport sector currently represent a quarter
of the UK's total emissions and are forecast to increase by 2010
as traffic grows.
Emissions of the most noxious air pollutants from road traffic
should fall to a half of present levels by 2010 due to improved
vehicle technology. However, this trend may be reversed after
2010 as a result of traffic growth and some urban areas may still
fail to meet the air quality objectives over the intervening period.
Carbon dioxide emissions
24. Voluntary agreements with global motor manufacturers to reduce
emissions of carbon dioxide have already been negotiated prior
to the launch of the Plan. The Baseline 2010 scenario contains
these reductions and the legislated reductions in toxic exhaust
emissions for new cars in Europe. Voluntary agreements with world
motor manufacturers will, it is assumed, provide a saving of 4MtC
of carbon dioxide emissions over the period of the Plan. The Plan
is expected to produce a further reduction of 1.6MtC of carbon
dioxide. Table 2
shows the estimated contribution of different elements of the
Plan to that 1.6MtC.
||2010 Carbon Dioxide Savings (MtC) compared to Baseline
|Trunk Roads||Generates 0.1
|Plan as a whole||1.6
|Plan plus constant motoring costs||2.4
Source: Transport 2010: The Background Analysis; fig 16,
25. The Department states that decisions taken in the Plan reflect
savings in vehicle-hours as a result congestion reduction and
the cost-effectiveness of expenditure on different measures to
achieve the carbon dioxide objectives. How that happened in practice
is not clear. For example, the Plan states that the increase in
carbon dioxide emissions from the extra traffic generated on trunk
roads (0.1 MtC) is "very small compared to the overall reductions
from the Plan as a whole".
However, the extra emissions generated by improved trunk roads
are five times the emissions expected to be saved by increased
rail passenger use, and the same as all the savings brought about
by local transport improvements. Friends of the Earth was concerned
that the Plan assumes a fall in motoring costs of 20 per cent
over the Plan period. Were motoring costs to remain constant,
there would be a further 50 per cent reduction (0.8 MtC) in carbon
dioxide emissions (Table 2).
Transport 2010: The 10 Year Plan, p13. Back
Transport 2010: The 10 Year Plan. Back
Fourth Report of the Transport, Local Government and the Regions
Committee, The Attendance of Lord Birt at the Transport, Local
Government and the Regions Committee, HC(2001-02) 655-I. Back
Tackling Congestion and Pollution: The Government's first
report under the Road Traffic Reduction (National Targets) Act
1998, DETR, January 2000. Back
Transport 2010: The 10 Year Plan, p9. Back
Tackling Congestion and Pollution, p14. Back
The strategic road network means the trunk roads currently operated
by the Highways Agency. It comprises nearly all motorways and
the more important A roads. Back
Transport 2010: The 10 Year Plan, p50. Back
The Baseline scenario describes changes to transport trends over
the 10 year period without the measures included in the Plan. Back
Tackling Congestion and Pollution, p23. Back
HC (2001-2002) 373-III Q580. Back
Running to Stand Still, Council for the Protection of Rural
England, 2001. Back
Transport 2010: The 10 Year Plan, p24. Back
Million tonnes of carbon dioxide equivalent. Back
Transport 2010: The Background Analysis, p32. Back
Transport 2010: Background Analysis, p33. Back