Guest post: If we all choose the fastest mode of travel in a city, the whole city gets slower – and more congested

The more people choose the fastest route by car, the more congested a city becomes. Alexander Popov | Unsplash, FAL

Rafael Prieto Curiel, UCL and Juan Pablo Orjuela, University of Oxford

People in cities often choose how to travel based on how long it will take. In recent years, navigation apps such as Google Maps and CityMapper have enabled people to decide between various modes of transport by seeing which one most quickly gets them where they want to go.

Cities of course have long dedicated a disproportionate amount of space to cars. Although in some parts of the global north – and in certain demographics – car use is declining, elsewhere it has, unsurprisingly, increased.

In a recent study, we modelled what would happen to average travelling times in a city if people were given only one other option – using the car or using another mode of transport – and if they acted only in their own interest (getting to their destination as fast as possible).

We wanted to see what would happen if everyone acted selfishly. How would that compare, we wondered, with a theoretical case in which people chose their mode to minimise travel times for society as a whole and not only for themselves.

City spaces

Using mathematical modelling, we found that if all travellers behave selfishly, and if we have a system that not only makes it relatively inexpensive to use a car, but also allows congestion to affect non-car users (cyclists, public transport users, pedestrians etc), collectively we all end up taking longer to get where we need to go – whether we’re driving a car or not.

City streets are often designed to make travelling by car faster and more efficient. And despite there being, for instance, an increasing amount of cycling infrastructure worldwide and higher satisfaction among people who commute by bike, it is still very common to see narrow, disconnected cycling lanes which result in congestion induced by private cars affecting cycling travel times too.

Mixed-use lanes – those that are used by both private cars and public buses, as opposed to dedicated bus lanes – have the same effect: car congestion affects bus users too. Without proper infrastructure, there are therefore no incentives to use public transport or active transport options, such as cycling and walking.

And even when there is a cycling path network or dedicated bus lanes, if these cross over or otherwise intermittently share space with the general road system, this also slows everybody down. It makes the system as a whole less efficient.

Similarly, free parking for private vehicles also results in longer travelling times for everyone – including non-car users – because they negate the benefits, for individuals, of not using a car if others still do.

We found that selfish behaviour with such inadequate infrastructure results naturally in more cars, more congestion, and longer travel times. If using a car remains the easier and quicker option (on an individual level), people will keep using cars and cities will remain congested. By trying individually to win, we all lose.

Competing priorities

One alternative is to design more collaborative transport networks in which we all accept some personal delay to achieve a distribution that is better for society. We could, for example, include not only personal cost in some of the apps we use, but societal costs also. What if Google Maps told you not only where congestion is in real-time and what would be the quickest transport mode to choose for you as an individual, but which transport mode would offer the best results for your neighbourhood, your family, your colleagues, or your city?

Research has shown how difficult it is, however, to shift commuter behaviour. It also highlights the public opposition there has been to alternative measures such as limiting maximum speeds in order to lower traffic injuries, despite such measures saving lives.

Given this, it could prove difficult to convince some car users to sacrifice personal efficiency for the greater good. But we could start by at least making these trade-offs explicit.

A giant spaghetti junction in Los Angeles.
Our cities are designed with car travel in mind. Denys Nevozhai | Unsplash, FAL

Motorised private transport has a wide variety of impacts that threaten a city’s sustainability, not least the wellbeing and health of its citizens. It contributes to air pollution and climate change through vehicle emissions and results in traffic injuries and nurtures sedentary lifestyles.

To encourage people to use more sustainable alternatives to car transport, cities need strong policies that steer people away from using their cars. So far, these have included low-traffic neighbourhoods and congestion charges that try to make car drivers pay for the congestion they are causing.

Elsewhere, systems have been implemented that attract people to transport modes, such as safe lanes for cycling, that typically have better environmental and social outcomes. These systems emphasise individualistic attitudes but target societal costs to those most responsible for them.

Ideally, we should create policies that help us act in the interest of our community. In the meantime, policies that push people away from their private cars could bring us closer to what would be optimal for the collective even if we are all acting in our own interests.

Rafael Prieto Curiel, Postdoctoral Research Fellow, the Bartlett Centre for Advanced Spatial Analysis, UCL and Juan Pablo Orjuela, Senior Research Associate and Executive Education Programme Director, University of Oxford

This article is republished from The Conversation under a Creative Commons licence. Read the original article.

Further reading: more from The Knowledge Exchange Blog on urban transportation

Future proofing Scotland’s road network

How can we ensure Scotland’s roads are fit for the future? That was the challenging question facing a panel of experts at this year’s Traffex Scotland exhibition. The exhibition – held for the first time at the SEC in Glasgow – attracted a large number of contractors, consultants, manufacturers and suppliers involved in the design, management and maintenance of Scotland’s roads and bridges.

Future-proofing the roads network was one of several seminars at the exhibition covering highway maintenance and development. The speakers on the panel were: Eddie Ross and Andy Thomson from BEAR Scotland (which maintains Scotland’s roads), Mark Arndt from Amey (a leading supplier of consulting and infrastructure support services both in the UK and internationally) and Evan Ferguson from Scotland Transerv (which manages and maintains more than 600 kilometres of trunk road and motorway network across South West Scotland).

The panel highlighted the challenges facing road maintenance engineers in assessing the current state of Scotland’s road network, and agreed that one of the key factors driving successful future development was to gain an understanding of the travel habits of the future. Gathering and sharing data will form the backbone of this understanding, enabling traffic managers to model, monitor and control the effects of travel as well as reducing congestion.

But the basics of road maintenance will always apply. Scotland has a diverse road network, and while trunk roads in the north of the country are often single carriage, requiring considerable improvements, elsewhere the challenges relate to capacity. Maintaining those roads, developing them for the future and ensuring minimum disruption to travellers and the economy are all exercising the minds of traffic engineers.

The climate and the weather are also important drivers of change. The panel wholeheartedly agreed that water is the road engineer’s enemy, and the increasingly wet weather experienced by Scotland can often lead to disruption for travellers.

The Scottish Government’s recent consultation on its National Transport Strategy highlighted extreme weather events, such as 2018’s “Beast from the East”, which cost the UK economy at least £1 billion per day as gridlocked roads, along with no trains and no buses meant many workers were unable to access employment.

The Traffex panel welcomed the National Transport Strategy as a good first step in future-proofing Scotland’s roads network. It highlights the need to enhance the resilience of the transport network, to enable new transport projects and policies to deal effectively with the predicted changes in climate and to adapt existing networks to allow for increased rainfall and extreme temperatures.

The panel also discussed some of the technological advances that are set to revolutionise travel patterns in the coming years. One notable development is the emergence of autonomous vehicles (AVs).

AVs need roads without impediments, and therefore need clear and well-maintained road surfaces, as well as road markings that are kept at high standards. At the same time, the ways in which AVs use roads may be different from conventional traffic, and this will have significant effects on the resilience of road surfaces.

Electric vehicles also herald profound changes to our roads, with implications for road pricing and infrastructure.

With only 20 minutes to cover the future of Scotland’s roads, the panel had their work cut out. But they ended, as they began, by stressing the need to understand the travel habits of the future. There was widespread agreement that the travelling public will be open to innovations such as AVs and electric vehicles, but will also expect improvements in connectivity options, including cycling and public transport.

Our road engineers will have a vital role to play in maintaining the roads network, while being flexible and open to new developments to keep Scotland moving.


Idox Transport delivers bespoke, cost-effective solutions to support strategic and localised transport control. Innovative services and solutions enable complete management across all forms of transport, supporting the safe and efficient movement of people and vehicles – whatever the end goal. To find out more, please contact the Transport team at transport@idoxgroup.com

Do planners dream of electric streets?

The last few years have seen a phenomenal growth in demand for electric vehicles in the UK.  Nearly 50,000 electric and plug in hybrid vehicles were registered between July and September 2017 a considerable achievement, when only 5 years ago it was less than 1,000.

Overall, there are now around 120,000 battery-powered cars on Britain’s roads, and this is expected to grow to 10m by 2035.  From the modest Nissan Leaf, to the futuristic Tesla, the choice of electric vehicles is expanding, and various car manufacturers have announced ambitious plans to develop even more electric vehicles to suit a range of tastes and budgets.

The benefits of moving to electric are clear – as well as lower emissions, they are also cheaper to run costing less than half as much than petrol-powered equivalents.

Out with the old

This means that a future where electric cars are the norm is now on the near horizon.  Indeed, the UK recently committed to banning the sale of new petrol and diesel cars, including hybrid vehicles, by 2040.  The Scottish government have set an even more ambitious target pledging that by 2032 all new vehicles sold in Scotland will be electric. Norway, India and France have also set similar goals.

At the local level, Oxford is set to become the first city centre to ban all non-electric vehicles with certain streets becoming electric-only by 2020, and the world’s first ultra-low emissions zone (ULEZ) will come into operation in London next year.

Delivery of EV infrastructure through the planning system

As desirable as a low emission, electric-only city may be, the use of electric vehicles poses a number of challenges for town planning and urban design.

Ensuring that there is sufficient infrastructure in place to meet the increased demand for electric vehicle recharging will be a key issue. While there has been a significant growth in the number and geographic spread of EV connectors across the UK since 2011, many more will be required if predicted demand is to be met.

While motorway services and petrol stations will soon be required by law to install charge points for electric cars, simply replacing existing fuel pumps with EV chargers will not provide sufficient capacity, as at present, charging an electric car can take anywhere between 30 minutes to a couple of hours.  Additional charging stations will have to be incorporated into parking spots – either on the road, at home or in car parks.

The planning system is already taking some practical action to address this. Both planning policy and development management provide important delivery mechanisms.

At the national level, in England, the National Planning Policy Framework states that

developments should be located and designed where practical to… incorporate facilities for charging plug-in and other ultra-low emission vehicles”.

In Scotland, high level planning policy also recognises the importance of considering EV charging infrastructure in new developments, with supportive text included in both the Third National Planning Framework and the Scottish Planning Policy 2014. In addition, permitted development rights for off-road charge points came into force in 2014.

At the regional level, some policies require planning authorities to incorporate facilities for charging electric vehicles.  For example, The London Plan states:

developments in all parts of London must… ensure that 1 in 5 spaces provide an electrical charging point to encourage the uptake of electric vehicles”.

Several local authorities also use local plan policies to require electric vehicle provision, and others use their development control powers to require developers to provide electric vehicle charging points.

Some authorities have also taken opportunities to broker EV via non-planning routes, for example, the provision of public recharging point provision through grants.  One such example the On-Street Residential Chargepoint Scheme was set up in 2016, and provides up to 75% of the cost of procuring and installing chargepoints.

Challenges remain

While progress is being made, a number of challenges remain.

As well as increasing the overall number of available charging stations, planners will need to ensure that they are adequately distributed within a city so that there’s always one within reasonable driving range.  Specifying EV charging points on new developments runs the risk of a ‘scattergun’ approach, particularly where developments are concentrated in specific areas.  Local authorities would do well to adopt a strategic and planned approach to EV provision to ensure adequate coverage.  This will be particularly important in rural areas, as electric cars typically have a maximum range of around 150 miles. ’Range anxiety’ is an affliction suffered by many electric car drivers!

While various grants are available for electric car owners to install charging infrastructure at their homes, it is also not yet clear how home EV charging will work in densely populated areas without private parking, such as large blocks of flats. One potential solution may be the use of massive batteries kept in shipping container-style boxes, with up to 50 charging points attached.

The provision of on street EV charging facilities may present a design challenge in historic and/or conservation areas. In London, this has been dealt with by retrofitting existing street lamps with EV infrastructure, even including heritage lamps in Kensington and Chelsea.

There have also been concerns about the ability of the national grid to cope with millions of cars being plugged in to charge every evening.  Encouraging drivers to charge ‘smart’ at off-peak times may be the way forward.

Innovative solutions

Despite these challenges, there are promising signs of progress.  Some noteworthy examples include Elgin-based housebuilder Springfield Properties committing to installing cabling for electric car charging points in all new-build homes as standard, including its new 3,000-home development in Perth.  There are also plans to turn the A9 into an ‘electric highway’ and for a new ‘charging hub’ in the centre of Dundee – which will also be part-powered by the use of solar canopies.

EV technology is an area of fast-paced change and addressing the many challenges that it presents will require planners to adopt similarly innovative and forward-thinking solutions.  With advances being made on contactless under-road EV charging, it may not be long before electric streets charge our cars on the move.  We in the Information Service are excited to see what the future holds, and will be keeping abreast of the latest developments in both policy and practice.


The Knowledge Exchange provides information services to local authorities, public agencies, research consultancies and commercial organisations across the UK. Follow us on Twitter to see what developments in policy and practice are interesting our research team. 

Is 20 plenty? The evidence for lower speed limits

20mph

Image from Flickr user Edinburgh Greens via Creative Commons License

By Donna Gardiner

This week (18-25 May) it’s Walk to School Week – where parents and children are encouraged to leave the car at home and experience the benefits of walking to and from school.

The campaign is particularly important given recent evidence which suggests that the number of children who walk to school is falling. The most recent Department for Transport National Travel Survey found that only 42% of children walked to school regularly in 2013, compared to 47% in 1995/97. Indeed, Britain has one of the lowest levels of children walking or cycling to school in Europe.

A recent YouGov survey of 1,000 parents of five- to 11-year olds in Great Britain found that speeding traffic was the main reason that parents no longer let their children walk to school. In particular, 39% felt that school-run traffic was dangerous. Almost two-thirds reported that they would like to see car-free zones outside both primary and secondary schools, as well as 20 mph speed limits in surrounding areas.

20 mph limits and zones

The introduction of 20 mph speed limits and zones has received widespread interest of late, with a number of large schemes, such as the one planned in Edinburgh, capturing the headlines. The Edinburgh scheme is particularly notable for its scale. It covers over 80% of the city’s roads – effectively making 20 mph the default speed for all of its urban areas. Implementation is due to start in late 2015.

At the other end of the UK, the London Borough of Hackney has this week begun the rollout of its own 20 mph scheme, through which more than 99% of the borough’s roads will become subject to 20 mph limits by October 2015.

The Edinburgh and Hackney schemes join a host of others across the UK, including those in inner London, Liverpool, York, Bath, Bristol, Manchester, Newcastle, Brighton, Oxford and Glasgow.

Support for further implementation

Numerous campaign and road safety groups have called for the greater implementation of 20 mph zones and limits across the UK, including the Royal Society for the Prevention of Accidents (RoSPA), Sustrans, the Campaign for Better Transport, CTC – the national cycling charity, 20’s Plenty for Us, The Slower Speeds Initiative and the European Transport Safety Council (ETSC).

The UK Government have also shown support for the wider implementation of 20 mph zones and limits. In 2013, they published revised guidance to make it easier for local authorities to implement 20 mph limits and zones in their areas, and earlier this year, new guidance which further supports 20 mph limits was published by Transport Scotland.

There is also clear evidence of the public’s desire for lower speed limits. A recent YouGov survey found that the majority of respondents supported the introduction of 20 mph speed limits in residential streets (65% support or strongly support) and busy shopping areas and busy streets (72%). Improved road safety and children’s safety were the key reasons for this, along with other reasons – such as making our streets more pleasant to live in, encouraging more walking and cycling, reducing noise and improving the quality of life.

The YouGov survey echoes the findings of the British Social Attitudes Survey 2013, which found 68% of people to be in favour of 20 mile per hour speed limits in residential streets.

Talking of the Hackney scheme, Cllr Feryal Demirci, Cabinet Member for Neighbourhoods and Sustainability, Hackney Council neatly summarises the anticipated benefits of 20 mph zones:

“We strongly believe this 20 mph rollout will be better for everyone. It will mean a safer, calmer and more liveable neighbourhoods for all residents, leading to more walking, cycling and playing outside, which in turn will have a positive impact on health and the community.”

Evidence of the benefits

But does the evidence support these anticipated benefits?

One of the most commonly cited benefit of lower speed limits is improved road safety, resulting from a reduction in the number and severity of collisions. There is widespread evidence that this is the case – for example, research published in the BMJ in 2009 concluded that 20 mph zones were effective measures for reducing road injuries and deaths. Specifically, their introduction was associated with a 41.9% reduction in road casualties, with the effect being greatest in younger children and for the category of killed or seriously injured casualties.

Similar findings have been reported elsewhere, for example, in a review of evidence reported to the London Road Safety Unit, in research by the DfT and by the SWOV Institute for Road Safety Research.

There is also evidence that lower speed limits may help to tackle health inequalities. This is because children and young adults are more at risk of road traffic accidents within poorer localities than in richer urban neighbourhoods. Indeed, in January 2014, Danny Dorling, Halford Mackinder Professor of Geography at the University of Oxford, went as far as to claim that implementing 20 mph speed limits was the main way in which local authorities could effectively improve the health of the local population and reduce health inequalities.

Similarly, research published in the Journal of Public Health in 2014 reported that targeting 20 mph zones in deprived areas may be beneficial. It also concluded that “20 mph zones and limits were effective means of improving public health via reduced accidents and injuries”.

Improved public health is another often cited benefit of lower speed limits. Evidence from Bristol and Edinburgh demonstrates that 20 mph zones do indeed encourage increased levels of physical activity, including walking and cycling, and there is also evidence that they improve resident quality of life, through increased opportunities for social interaction and less noise and air pollution.

The reduced levels of pollution also mean that lower speed limits can be better for the environment.

Finally, there is also some evidence that 20 mph zones may result in increased local economic activity – with improved walking environments having many potential benefits for local business. Research conducted by Living Streets in London also found that pedestrians tended to spend more than those arriving by car.

Driver concerns and attitudes

Despite the evidence in their favour, 20 mph zones are not always welcomed with open arms. There remain a number of concerns about the implementation of 20 mph zones, including fears that they may lead to increased levels of congestion, increased carbon emissions, suffer from a lack of enforcement, increase journey times, and increase emergency response times.

Most of these concerns have been countered by research evidence; however, attitudinal barriers remain. In an analysis of a YouGov survey of public attitudes towards 20 mph zones, Professor Alan Tapp of UWE Bristol, reports that a sizable minority of people (31%) claim that ‘If a 20 mph speed limit is introduced, I may not stick to it’. He also points out that 49% felt that ‘It is just too difficult to stay at 20 mph’ and almost a third of people (30%) thought that 20 mph is an example of a nanny state.

The way forward

So despite the progress that has been made, there is clearly still some way to go before 20 mph limits and zones become a fully accepted part of UK towns and cities. Implementing more 20 mph limits is only the start – it seems that there is also a need for local authorities to tackle the negative perceptions of 20 mph zones held by many drivers in order to ensure that 20 mph limits are adhered to in practice.

Sharing evidence of the positive benefits of 20 mph zones and demonstrating that many of the main concerns associated with them are ill-founded is likely to play an important part in encouraging more positive attitudes, changing driver behaviour, and in turn, make streets safer and more enjoyable for children and adults alike.


 

The Idox Information Service can give you access to further information on improving road safety. To find out more on how to become a member, contact us.

Further reading:

Addressing health inequalities: five practical approaches for local authorities (Perspectives in Public Health, 2014)

Reducing unintentional injuries on the roads among children and young people under 25 years (Public Health England, 2014)

Road safety and public health (The Royal Society for the Prevention of Accidents, 2014)

Achieving safety, sustainability and health goals in transport (Parliamentary Advisory Committee for Transport Safety (PACTS), 2014)

Unlimited aspiration for a calmer city (speed limits) (Local Transport Today, 2011)

Sign of the times (20 mph speed limits in Portsmouth) (Parking Review, 2010)

Review of 20 mph zone and limit implementation in England (Department for Transport, 2009)

A bumpy road ahead: recent bad weather highlights the state of UK roads

bike in flood

by James Carson

The storms which have continued to batter much of the UK since the end of 2013 have thrown into sharp focus the state of the country’s roads, something highlighted by an article in this month’s issue of The Surveyor. Continue reading