Memorandum by PACTS (RP 28)
ROAD PRICING
1. The Parliamentary Advisory Council for
Transport Safety (PACTS) welcomes the opportunity to respond to
this inquiry. PACTS is an associate parliamentary group and registered
charity advising and informing Members of Parliament on road,
rail and air safety issues. It brings together technical expertise
from the public, private, academic and professional sectors to
promote research-based solutions to transport safety problems.
Its charitable objective is to promote transport safety legislation
to protect human life. This memorandum will therefore consider
the safety implications of road pricing, particularly relating
to the first three of the Committee's questions:
— Should road pricing be introduced
for certain sections of the road network in the short term?
— If road pricing is introduced, what
factors should determine which roads are priced and what technology
should be used?
— How "hi-tech" does road
pricing need to be?
2. Innovative schemes for road pricing,
applied at a national level, have significant scope for reducing
congestion and changing patterns of road use. While there may
be positive road safety implications in the longer term if road
pricing leads to a modal shift from motorised traffic to other
transport modes that cause less risk, road pricing is not in itself
a road safety proposal. Road pricing may also be of benefit in
that it may allow the negative externalities of motoring (including
safety, health and environmental implications) to be reflected
by the costs of motoring in a far more direct and immediate fashion
than at present. However, these two aims of roads pricing may
lead to different practical considerations, and a balance between
them may need to be struck. In short, the objective of road pricing
must be determined before a scheme can be designed.
3. PACTS has no opposition to road pricing
in principle, but it must be implemented in a manner that does
not increase road risk, particularly to vulnerable road users.
This will require careful consideration and appropriate modelling
of all possible impacts of road user charging.
4. The relationship between congestion and
crash risk is a complex one, and reducing congestion can have
variable effects on casualty reduction. Although a connection
between traffic growth and an increase in road casualties is often
assumed, recent research commissioned by the Department for Transport
found:
Despite this presumption . . . is the reality
of the situation was that, with the exception of motorway sites,
accident rates during periods of recurrent congestion are lower
than those in uncongested conditions. (Brownfield et al 2004:
5)
The study found that while for motorway sites
the accident rate in congested conditions was nearly twice the
rate in uncongested conditions, in urban and "peri-urban"
sites the accident rate in congested conditions was less than
half the rate in uncongested conditions. Rate was calculated by
road length rather than "per vehicle kilometre", which
suggests that crash rates per vehicle are significantly lower
in congested conditions, as traffic flows are higher in congested
conditions. For vulnerable road users, congested conditions lower
crash risk even further. Crash risk for cyclists and pedestrians
are dramatically lower in congested conditions: in urban sites
the accident rate for pedestrians in congested conditions was
a quarter of the rate for uncongested conditions; this falls to
a seventh in peri-urban sites (Brownfield et al 2004: 6).
5. TRL modelling of motorway tolling has also
indicated that motorway tolling could increase crashes due to
the diversion of traffic from motorways (which tend to have good
collision records) to alternative untolled roads (which may be
less safe and less appropriate for high vehicle flows). A study
based on motorways in Kent suggested that a toll of 2.5p per mile
(at 1994 prices) would produce a 10% diversion level (Gower et
al 1998). A linked study suggested that "a 10% diversion
of motorway traffic from the motorways in Kent would increase
the number of injury accidents in the entire county by about 3½%"
(Broughton and Gower 1998: 7). The cost of these crashes represents
29% of the revenue that would be raised from the tolls, considerably
undermining the tolls' effectiveness. If these conclusions were
to apply nationally, it would be an extremely unwelcome result.
6. However, depending on the nature of the
scheme, road user charging does not necessarily lead to an increase
in casualties—as the experience of congestion charging in
London has demonstrated. Casualties in the congestion charge zone
fell at a quicker rate than elsewhere in London after the charge
was introduced, and the sharp reductions in road casualties across
London does not suggest that crashes have been displaced as drivers
alter their routes (TfL 2004: 94). Further analysis into the long-term
effects of congestion charging in London on road casualties would
be welcome.
7. The potential negative safety implications
of road pricing is recognised in the DfT Feasibility Study
of Road Pricing in the UK, published in July 2004:
The impact of re-routing, if it were to occur,
could in certain places and at certain times result in an increase
in accident levels. This is due to the increased number of vehicles
using smaller roads, not built for a high level demand, which
could lead to higher accident rates. However, a well-informed
charging structure could minimise the incentives to re-route.
(DfT 2004a: 143)
This is an important consideration and needs
to be integral to the design of road pricing schemes.
8. A "well-informed charging structure"
would be one that seeks to take into account crash risk and associated
costs as well as congestion and emissions. This could have positive
benefits for road safety as drivers are encouraged to use safer
routes. However, research suggests that a complex charging structure
could inhibit the effectiveness of road pricing schemes. A recent
report on pricing structures for road user charging concluded:
The clarity of the pricing signal is fundamental
to the success of congestion charging. The prime requirement is
that the logic of the charge structure, and the necessity of a
degree of complexity, is capable of being communicated and is
seen to reflect the objectives of the scheme. The logic should
be capable of being summed up in a relatively simple expression
such as "Charges will be highest when and where traffic is
expected to be busiest". (Bonsall et al 2004: iv-v).
Introducing variables beyond congestion, such
as road risk and environmental considerations, could lead to pricing
structures that are nearly impossible for ordinary drivers to
understand, and would therefore be ineffective in achieving behavioural
shift.
9. The Feasibility Study of Road Pricing
in the UK also raises the issue of a potentially negative
form of modal shift:
If motorcycles are exempted from road pricing
they could become more popular, which would have implications
on road safety. This is because motorcyclists have been found
to be eight times more likely than car drivers to be involved
in an injury accident, over 20 times more likely to be injured
themselves, and over 35 times more likely to be killed or seriously
injured (DfT 2004a: 143).
The study notes that in the London Congestion
Charge scheme an increase in the number of motorcycles has not
led to increases in casualties. However, this may not be representative:
motorcycle speeds within London are likely to be significantly
lower than outside the Capital, and in recent years an increase
in motorcycling nationally has led to a sharp increase in motorcyclist
deaths and serious injuries (DfT 2004b). PACTS therefore recommends
that motorcycles should not be exempt from road pricing.
10. Speed and casualty severity is another
important issue. The Feasibility Study of Road Pricing in the
UK notes: "the improved free flow of traffic could also lead
to an increase in the severity of accidents ie from shunts to
fatalities" (DfT 2004a: 144). The study suggests that a proportion
of revenue from road pricing could be devoted to speed management
measures to mitigate against this effect. This is a welcome suggestion.
It will also be important to integrate road pricing into existing
speed and traffic management systems as a whole.
11. "Hi-tech" versions of road
pricing could improve road safety through sharing a technology
platform with Intelligent Speed Adaptation (ISA). Both road pricing
and ISA have similar technological requirements: accurate vehicle
location technology and digital maps containing local road information.
As the Transport Committee has noted on a number of occasions,
ISA has a major potential for reducing road casualties and could
reduce fatal collisions by up to 59% (Transport Committee 2004;
Transport, Local Government and the Regions Committee 2002). Further
consideration into how road pricing could link to ISA and other
innovations such as Norwich Union's pay-as-you-drive insurance
would be desirable.
12. In conclusion, while road pricing may
be welcomed in principle, significant attention will need to be
given to the practicalities of road pricing scheme to ensure that
there is no deleterious effect on road safety. Based on the findings
of TRL research on motorway tolling, PACTS does not believe that
road pricing should be introduced on trunk roads in the short
term as an intermediate step to national road pricing. However,
urban area-based schemes such as London's congestion charge may
be more effective at introducing a form of road pricing without
compromising safety. In the longer-term, consideration needs to
be given to whether and how safety variables can be integrated
within pricing structures and to whether any negative safety implications
of road pricing can be mitigated through other measures. Integrating
Intelligent Speed Adaptation with road pricing technologies may
be one very positive method of achieving this.
REFERENCES AND
FURTHER READING
Bonsall, P, Shires, J, Matthews, B, Maule, J and
Beale, J 2004. Road User Charging—Pricing Structures.
Final report for the Department for Transport on PPAD 09/159/002.
The Institute for Transport Studies, University of Leeds: Leeds.
Broughton, J, and Gower, P 1998. The likely effects
of motorway tolling on accident risk—phase 2. TRL Report
TRL352. Transport Research Laboratory: Crowthorne, Berks.
Brownfield, J, Graham, A, Eveleigh, H, Ward, H, Robertson,
S, and Allsop, R. 2003. Road Safety Research Report No 44:
Congestion and accident risk. Department for Transport: London.
Gower, P, Shearn, S, and Mitchell, J. 1998. Motorway
tolling: Modelling the impact of diversion. TRL Report TRL349.
Transport Research Laboratory: Crowthorne, Berks.
Department for Transport. 2004a. Feasibility Study
of Road Pricing in the UK. DfT: London.
Department for Transport. 2004b. Tomorrow's Roads-safer
for everyone: The first three year review: The Government's road
safety strategy and casualty reduction targets for 2010. DfT:
London.
House of Commons Transport Committee. 2004. Cars
of the Future. Seventeenth Report of Session 2003-4, Volume
1. HC 319-I. House of Commons/TSO: London.
House of Commons Transport, Local Government and
the Regions Committee. 2002. Road Traffic Speed. Ninth Report
of Session 2001-2, Volume 1. HC 557-I. House of Commons/TSO: London.
Transport for London. 2004. Congestion charging—Central
London—Impacts Monitoring: Second Annual Report. TfL:
London.
PACTS
November 2004
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