Less traffic

  • Research reveals that exposure, in terms of total vehicle travel, is a risk factor to those both inside and outside the vehicles. 
  • Road safety policies must, therefore, do more than tackle dangerous driving and include actions for traffic reduction, including road pricing, planning for compact neighbourhoods, improved public transport and infrastructure changes such as low-traffic neighbourhoods.
  • In other words, to eliminate road danger we need to reduce the principal cause of that danger at source: the number of vehicles on our streets and roads.
  • The benefits are wide-ranging not just for road safety but also air quality; carbon emissions; more active lifestyles; and healthy, attractive streets.

New research by Todd Litman, from the Victoria Transport Policy Institute in Canada, concludes that all motor traffic exposes people to danger. This means that road safety policies must do more than tackle dangerous driving and include actions for traffic reduction, such as road pricing. In doing so, Vision Zero is not just about solving road danger, but also our air quality, climate change and inactivity crises.

Litman analyses traffic statistics and research to reveal that exposure, in terms of total vehicle travel, is a risk factor to those both inside and outside the vehicles. 

For example, when fuel prices rose between 2004-13 in the United States, people drove less and deaths went down. Then when fuel prices decreased after 2014 and traffic levels rose again, so did deaths. He quotes research that shows “each 1% increase in per capita Vehicle Miles Travelled (VMT) is associated with a 0.55% increase in traffic deaths (Yeo, Park and Jang (2015)).

The findings also apply in a European context. A study by University of Lancaster in 2015 found that the London Congestion Charge not only resulted in “meaningful” reductions of traffic volumes, but also “substantial” and “significant” reductions in accidents and fatalities – both in the charged area and in adjacent areas.

It’s also worth remembering that the vast majority of serious and fatal collisions on roads involve motor vehicles. In London, TfL research has shown that of the 779 serious or fatal pedestrian casualties in 2014, 753 (96.7%) were the result of a collision with a motor vehicle and 26 (3.3%) from collision with a pedal cycle. 

Persistent growth of car traffic

Reducing car usage is one of the hardest goals to achieve. It is also contrary to the aims of governments that view motor vehicle usage through the narrow prism of rapid economic and GDP growth. In the UK we still see substantial funding for new roads, freezes on fuel duty alongside limited funding for public transport and active travel and a planning system that promotes car-based development. 

Governments conveniently overlook the problems that a reliance on motor vehicles brings, including increased obesity and reduced activity, the cost of road casualties, the deaths and illness caused by poor air quality and even a reduction in community life

Long-term trends in the UK show just how difficult it has been to halt the growth in car usage. Since 1949, the DfT finds that the only significant blips in the growth in vehicle usage have been the oil crisis of the early 1970s, the recession of the early 1990s and economic crash from 2007.

Road Traffic Estimates: Great Britain 2018, Department for Transport

It is time to reverse this growth and there are a number of strategies that government, at all levels, can implement right now.  

There is a great summary of the impact of various different measures in a April 2022 report by the Lund University Centre for Sustainability Studies and published in Case Studies on Transport Policy. The study study ranks the 12 most effective measures that European cities have introduced in recent decades, based on real-world data on innovations ranging from the “carrot” of bike and walk-to-work schemes to the “stick” of removing free parking. The most effective measures, according to the review, are introducing a congestion charge, which reduces urban car levels by anywhere from 12% to 33%, and creating car-free streets and separated bike lanes, which has been found to lower car use in city centres by up to 20%. The report is summarised in a blog in The Conversation.

Road user charging

The London Congestion Charge, introduced in Central London in 2003, was initially successful, with a 18% reduction in traffic during charging hours in 2003 compared to 2002. This scale of reduction was maintained the following year.

Traffic entering the western extension of the London Congestion Charge, that operated between 2007 and 2010, during charging hours was down 14% in 2007. These reductions were maintained into 2008. The research from Transport for London is available here.

In Stockholm, traffic to and from the inner-city cordon was reduced by 20% when the congestion charge was introduced in 2007. Vehicle miles travelled decreased by 14% after its variable pricing system was introduced in 2016 and traffic congestion fell by 5%. More here.

Singapore‘s first cordon scheme was established in 1975 and the current Electronic Road Pricing (ERP) System was introduced in 1998. Despite strong population growth, the ERP has reduced traffic in the inner city by 24%.

But the time has come for a more advanced system of road user charging that properly reflects the level of vehicle usage and the real cost of car journeys.

In London, the potential to investigate new schemes is envisaged in Proposal 21 of the adopted Mayor’s Transport Strategy. “The Mayor, through TfL, will investigate proposals for the next generation of road user charging systems”.

In April 2019, the Centre for London produced a report Green Light: Next Generation Road User Charging, which recommended that London should continue to lead the way in making the most of new technology and develop a simpler, smarter and fairer system of road user charging. In these proposals, drivers would be charged on a per-mile basis based on distanced travelled, vehicle emissions, local levels of congestion and pollution, and availability of public transport alternatives.

In New York there are plans for a charge to be levied through an electronic tolling system from 2021 for vehicles that enter Manhattan below 60th Street. More here.

Workplace Parking Levies

While many local authorities have considered them, Nottingham City Council is the first to establish a levy on workplace parking spaces. The levy, introduced in 2012, is an annual charge of £417 per parking place for employers with 11 or more spaces (as of 2018-19).

It costs around £500,000 a year to run but raises £9 million a year, which is used to fund improvements to public transport in the city to further reduce car dependency. The city has used the money to bid for other sources of match funding for the city. The Department for Transport (DfT), for example, matched £221 million of local funding with £432 million for the extension of the city’s tram network.

In terms of impact, public transport usage is now among the highest of any city in the UK (more here). Nottingham was also the only Core City in England to see congestion fall on A-roads in the morning rush hour from 2012, when the levy was introduced.

Workplace Parking Levies are currently being considered by a number of London boroughs including Hounslow, Merton, Brent and Camden.

Creating car-free areas

Oslo is currently in process of creating an (almost) car-free city centre. The key components of this movement are the removal of car parking spaces, increasing road tolls, closing streets to traffic, creating bicycle lanes and encouraging delivery by cargo bikes.

Spain too is moving ahead with significant restrictions on vehicle usage across its cities. Leading the way is Madrid, which is using a combination of bans on through-traffic and stringent restrictions on more polluting vehicles to restrict access to parts of the city centre.

Low-traffic neighbourhoods

Neighbourhoods can also reduce traffic volumes by restricting access for motor vehicles.

The TfL-funded Salisbury Row Streets for People scheme introduced a series of road closures, public realm improvements and greening in East Walworth in 2011 which led to significant reduction of motor traffic and increase in walking and cycling. This included a 58% reduction in vehicles travelling over 20mph; 71% overall reduction in traffic; and an increase in peak morning pedestrian numbers across all the streets of 83%.

Impact of the Salisbury Row Streets for People Project (Implemented 2009)

Low-traffic Neighbourhoods (LTNs) are residential areas where modal filters (bollards, planters or bus gates) are introduced to remove through traffic but allow people to access homes, albeit on slightly longer routes.

As of May 2019, Waltham Forest Council has created three large LTNs in Walthamstow Village, Blackhorse Village and Leyton Town Centre. Details about these projects is available from the Enjoy Waltham Forest website and here.

In Waltham Forest there have been considerable traffic reductions on streets within the neighbourhoods – some streets have seen 90%+ reductions in motor traffic and 56% on average. On the surrounding roads there have been increases, but they have not taken all the displaced traffic. More here.

Early research into the impact of the Walthamstow Village scheme found a positive story in relation to casualties, with an average of five slight collisions per annum before the scheme went in and no collisions recorded in the 11 months following its implementation.

Research from the Active Travel Academy at the University of Westminster (@Active_ATA) into LTNs that were introduced in London in 2020 (see map below) found that, “numbers of injuries inside LTNs halved relative to the rest of London”; there was “substantial reductions in pedestrian injury risk”; and there was “no evidence of changes in injury numbers or risk at boundary roads”.

The research shows that the potential impact of LTNs for pedestrians appears particularly strong with large decline in casualties on roads inside LTNs “Pedestrians saw a particularly steep decline both in absolute and relative injury risk”

The research can be found in full here.

London Living Streets and London Cycling Campaign have produced a number of guides about Low Traffic Neighbourhoods, available here.


The easiest way to reduce the danger of large vehicles is to cut their numbers on streets, for example by:

  • replacing freight deliveries by motor vehicles with cargo bikes (read about London Bridge’s businesses switching to cargo bike here);
  • encouraging construction materials to be transported by rail or river where possible; and
  • developing construction vehicle holding areas that can help reduce the risk of lorries having to back out of sites or circle the area waiting to make a delivery (more on the Old Oak and Park Royal construction and logistics strategy to download here).

Behaviour change

In addition to these cost- and infrastructure-based initiatives, behaviour change can also reduce vehicle usage. Examples of this are:

  • personalised travel planning, such as in York, where incentives for using public transport, bicycling and walking and car-sharing produced a 16% reduction in car trips across households in three city-centre wards; and
  • travel planning, or a package of actions designed by a workplace, school or organisation to encourage sustainable travel options.
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