There’s a long-running stink about building a fourth Park-and-Ride facility on the edge of Exeter, this time near Alphington at the junction of the A30 and A377 roads.  Devon County Council has just withdrawn its second planning application, partly because of furious local objections but also because the goals originally claimed for the scheme seems to have evaporated.

That’s not entirely surprising.  Despite P&R as a “solution” to urban traffic congestion becoming something of a no-brainer in the popular psyche, its benefits are not always realisable and there are some serious downsides.  This post looks at the evidence.

Central government policy

Government policy on P&R schemes has fluctuated over time.  Initially left as a matter entirely for local authorities, central government up to 1997 recognised their role in reducing congestion but noted that there were potential disbenefits, particularly by encouraging additional car journeys.  From 1997, central government policy actively promoted P&R schemes, though with a much greater emphasis on them as part of a coordinated package of measures to achieve modal shift aligned to local circumstances.

Following the change of government in 2010 and the replacement of previous planning guidance with the National Planning Policy Framework, references to P&R schemes disappeared.  A sole reference in Planning Practice Guidance merely suggests that existing P&R schemes should form part of the evidence base for developing local transport plans [1].

Exeter commitments

The Devon Implementation Plan for the Devon & Torbay Local Transport Strategy 2011-2016 [2] envisages a new Park and Ride (P&R) facility to serve the Alphington Road corridor, for which a planning application has been submitted.  The Plan also envisages a P&R to the north of Exeter, though no detail is available.

The Plan assumes – though no evidence is cited in support – that P&R schemes provide benefits [3], specifically:

• Enabling increased demands for access to Exeter City Centre from surrounding areas, alongside improved inter-urban bus services and the rail-based Devon Metro.
• Reducing congestion
• Reducing air pollution.

The Plan states that there is strong public support for new P&R schemes.

The research evidence on P&R schemes

There is relatively little evidence about the effectiveness of P&R schemes.  A few studies were carried out in the 1990s, and these are still cited in more recent work.

There does appear to be a consensus among those who have undertaken studies that:

• There are downsides as well as upsides to P&R schemes
• Any P&R scheme should be developed as part of an overall package of strategic proposals, and not in isolation.
• There is sufficient evidence to cast doubt on the orthodoxy that P&R schemes lead to reductions in car use and the associate environmental benefits.

The most recent readily available review of the evidence on P&R schemes was published in 2008[4].  Drawing heavily on earlier work in the 1990s, the study identifies three broad policy goals for P&R schemes: transport, environmental and economic.

Transport

Do P&R schemes divert people from public transport, and with what consequences?

P&R schemes are targeted at intercepting car users from routes into city centres so removing cars and reducing traffic flow between the P&R and the centre.  But the incentives – eg fares [5], frequency, comfort – to use P&R can draw people away from existing public transport services, with consequences for their continuing viability.  Research shows significant numbers of P&R users are people have switched from other public transport in this way.  Reinforcing this from the other angle, Brighton does not have a P&R system and some councilors believe this accounts for the high use of buses from surrounding areas [6].

Do P&R schemes reduce congestion?

The evidence is weak, though interception rates between 17% and 25% have been reported for Oxford’s (well-established) P&R schemes.  Devon County Council has no information about interception rates at the existing P&R sites in Exeter, and so has no firm basis with which to justify further schemes.   It seems likely that P&R will only contribute to reducing congestion levels if backed up by other stronger methods, such as reducing city centre car parking (or charging punitively for it).  Otherwise the city centre space freed up by drivers diverting to P&R will fill up with other drivers.  Road pricing or congestion charges may also be needed.

Do P&R schemes lead to more car journeys?

There is evidence that people who might once have made their entire journey by public transport switched to driving from home to the P&R site, then continuing by P&R bus.  The perceived attractiveness of P&R can also lead people to undertake journeys they would not have done in the absence of P&R.

Environmental

Broadly, reducing emissions as a goal of P&R policy depends on reducing the number of car journeys (see above).  In addition, it is necessary for the additional buses introduced for P&R services to be low-emitting if the emissions savings from car journeys are not simply cancelled out by bus emissions.

Construction of P&R sites and localised emissions concentrations from cars using the P&R can also have adverse environmental effects.

Economic

There is a general consensus that P&R can bring economic benefits to city centres.  Local authorities often cite this as a justification for introducing the schemes.   However, there can be competition implications for surrounding centres.  If people divert to the city centre from other areas, this can be beneficial if it reduces demand for out-of-town shopping centres (which in turn leads to car mileage reductions); but it can also damage the viability of district centres and smaller surrounding towns/villages.  Again, there is insufficient evidence to draw clear conclusions.

There is no clear correlation between the introduction of P&R parking places and the number of reductions in city centre parking spaces.  Where city centre parking spaces are reduced there is potential to find a more economically buoyant use for the land.

An overall conclusion

It is difficult to improve on the following statement in a 1998 briefing from the Campaign to Protect Rural England [7].  Despite being nearly 20 years old, it has not been invalidated by subsequent evidence.

Ultimately, Park and Ride schemes are probably best viewed as an interim solution. They do not eliminate car dependency and once they reach saturation point, local authorities are left with the prospect of surrounding our towns and cities with an ever increasing number of car parks. In the end, the root causes of traffic growth have to be tackled. This requires the long term process of integrating land use planning with the need to reduce dependence on the car.

 

NOTES

[1]  See http://planningguidance.communities.gov.uk/blog/guidance/transport-evidence-bases-in-plan-making/transport-evidence-bases-in-plan-making-guidance/ para 006.

[2]  Both documents available at https://new.devon.gov.uk/roadsandtransport/traffic-information/transport-planning/devon-and-torbay-local-transport-plan-3-2011-2026/

[3]  See para 4.5.3 of the Implementation Plan

[4]  Role of Bus-Based Park and Ride in the UK: A Temporal and Evaluative Review: Stuart Meek, Stephen Ison and Marcus Enoch, Transport Reviews, Vol. 28, No. 6, 781–803, November 2008

[5] For example, a 7-day P&R-only megarider ticket in Exeter costs £10 whereas the general 7-day megarider costs £14.

[6]  Quoted on p191 of Urban Transport without the Hot Air, vol 1, Steve Melia, UIT Cambridge, 2015.

[7]  Park and Ride – Its role in local transport policy, CPRE, 1998.