Is 20mph really plenty?

News stories are free to read. Click here for full access to all the features, articles and archive from only £8.99.

On top of Euro VI, PSVAR, staff shortages and long waits for new vehicles, there is another issue that is starting to become more and more apparent to both coach and bus service drivers, and the management of any operator that is involved in express or bus service work, and that is the 20mph speed limit that is currently springing up all over the UK.

A long-standing limit

Country to common misconceptions, the implementation of the 20mph speed limit is by no means new, having first been considered by the Department for Transport in 1990, based on experience of the cut speed limit internationally. In December of that year, the Department of Transport (DfT) issued circular Roads 4/90 which set out guidelines for the introduction of 20mph speed limits, with local authorities having to apply for consent from the Secretary of State to introduce a 20mph zone.

There is a difference between a 20mph limit and a 20mph zone, with a 20mph limit being shown by road signs, whilst a ‘20mph zone’ is designed to be ‘self-policing with traffic calming measures in addition to signage.

Tinsley in Sheffield was the first location in the UK to gain a 20mph speed limit, at the junction between Raby Street and Sheffield Road, whilst the first 20mph zones were in Kingston-upon-Thames and Norwich. A further 450 20mph speed limits were introduced between its inception in 1991 and 1999.


In September 2019, Transport for London (TfL) announced that proposals to lower speed limits on TfL roads across central London would go ahead, following a positive response to its public consultation earlier in that year. TfL went on to introduce 20mph speed limits on all its roads in the capital’s Congestion Charge Zone by early 2020 – mirroring the lower speed limits already in place on the majority of borough roads in the central London area.


Are you enjoying this feature? Why not subscribe to continue reading?

Subscribe for 6 issues/weeks from only £6Or login if you are already a subscriber

By subscribing you will benefit from:

  • Operator & Supplier Profiles
  • Face-to-Face Interviews
  • Lastest News
  • Test Drives and Reviews
  • Legal Updates
  • Route Focus
  • Industry Insider Opinions
  • Passenger Perspective
  • Vehicle Launches
  • and much more!

As is normal practice where these schemes have been implemented, 20mph signs and road markings were introduced, but in addition TfL recalibrated all speed cameras in central London and used mobile speed cameras to ensure that drivers were complying with the new safer speed limit.

There were nearly 2,000 responses to TfL’s public consultation, with half of respondents saying the plans would have a positive impact on walking and 31% saying that many more people would choose to walk. Almost two-thirds (59%) thought that the proposals would lead to more people cycling and four in 10 thought that the proposals would have a positive impact on public transport.

The move was a key part of the Mayor of London’s Vision Zero ambition to eliminate death and serious injury from London’s transport network, with Sadiq Khan, saying at the time: “Every single death on London’s streets is one too many so I’m really pleased that Londoners have backed our plans to introduce a 20mph speed limit on TfL roads within the Congestion Charge Zone and at Aldgate Gyratory. By also bringing forward plans to lower speed limits in other parts London, we will help protect more people walking and cycling across our city.”

There are more than 1,200 roads included in the 20mph scheme throughout Portsmouth. RICHARD SHARMAN


Portsmouth City Council was the first local authority in England to implement an extensive citywide 20 mph speed limit scheme. Introducing a citywide 20mph limit enabled Portsmouth to use terminal and repeater signs as opposed to expensive engineering calming features such as speed cushions and build outs.

This was achieved by splitting the city into six sectors of roughly equal size to implement the scheme, and the implementation included erecting gateway signs at the junctions of roads which were included in the scheme and roads that would remain 30mph. The scheme was completed in March 2008 and since then Portsmouth City Council has been working on the post scheme analysis which includes before and after speed analysis, and before and after KSI (Killed or Seriously Injured) data. This data has been used to produce a report by Atkins Consultancy on behalf of the Department for Transport which evaluates the implementation. One of the key findings from the report is that vehicular speeds which were high have dropped considerably whereas there hasn’t been much change where speeds were already low.

Portsmouth City Council said that, overall, the 20mph scheme in the city had been a success and the majority of residents believe the scheme had benefited the city, noting that there has been huge interest in the scheme from other local authorities across the country as well as organisations carrying out events regarding the scheme.

Reasons for 20mph

‘20’s Plenty for Us’ is a not-for-profit organisation with nearly 700 local groups campaigning to make urban areas better places to be. With no political leaning or backing, the group says it works with all administrations to assist the setting of 20mph speed limits as a norm. It campaigns for a speed limit of 20mph to be normal on residential streets and in town and village centres, unless full consideration of the needs of vulnerable road users allows a higher limit on particular streets.

Rod King MBE, the founder of 20’s Plenty for Us commented: “All over the world authorities are finding that 20mph limits deliver lower speeds, lower casualties and more pleasant places to live. Authorities with a population of 28 million people in the UK have already said that 20’s plenty where people live, play, work, learn and shop. The current 30mph national limit for England is clearly no longer fit-for-purpose. With 79,000 casualties on England’s 30mph roads in 2019 (26,500 being pedestrians and cyclists), it’s time for the UK government to set a national default 20mph urban/village limit with exceptions only where evidentially safe for vulnerable road users. The benefits would transform the safety and livability of our communities.”

Pedestrians cross the road outside Tooting Bec station in London; a 20mph speed limit is in force in many areas of the city and beyond. TfL

The Royal Society for the Prevention of Accidents (RoSPA) says that local authorities should take advantage of opportunities to introduce 20mph roads, and that they should be prioritised in places where they are most needed, for example in areas of social deprivation which have high populations, areas which consistently display collision problems or have other issues which a 20mph zone could alleviate, and in residential areas around locations which are common urban destinations, as well as on school routes. Speed limits can, and should, be supported by other measures to help drivers drive at safe speeds, and to enforce the limits for drivers who choose to ignore them, the Society says.

TfL released new data in February of this year that showed a significant reduction in the number of collisions since the implementation of 20mph speed limits on key roads in London.

Monitoring showed the number of collisions has reduced by 25% from 406 to 304, and collisions resulting in death or serious injury have reduced by 25% from 94 to 71, which TfL says demonstrates the impact of lowering speeds across the city. Since the 20mph speed limits were introduced, the number of reported collisions involving vulnerable road users has decreased by 36% from 453 to 290, while collisions involving pedestrians have decreased by 63% from 124 to 46.

Currently over half of London’s roads have a 20mph speed limit, of which almost 110km is on TfL’s road network. TfL is now working to lower speeds on 220km of its roads by 2024 in inner and outer London and plans to introduce a new 20mph speed limit on over 28km of roads in Camden, Islington, Hackney, Tower Hamlets and Haringey in March. It is also working with the Metropolitan Police to increase its capacity to take enforcement action against drivers and riders who exceed the speed limit. The ‘Met’ is on target to be able to take action on a million speeding offences by 2024.

In 2021/22, it enforced 476,685 speeding offences, an increase of 72% compared to the previous year.


The Welsh Government revised its documentation for the reasons behind the reduced limit last year, saying that introducing a 20mph default speed limit on residential roads and busy pedestrian streets across Wales will:

  • save lives and reduce the risk and severity of injuries from collisions between vehicles and vulnerable road users;
  • make streets safer for playing, walking and cycling;
  • encourage more people to make more sustainable travel choices;
  • makes Wales more attractive for our communities;
  • bring physical and mental health benefits;
  • reduce noise pollution, promote cleaner air and be better for the environment.

First Minister Mark Drakeford said: “Reducing speeds not only saves lives, it helps build safer communities for everyone, including motorists – better places to live our lives.

“It will help make our streets quieter, reducing noise pollution, and slower speeds will give more people the confidence to cycle and walk around their local areas and encourage children to play outdoors. Evidence from around the world is clear – reducing speed limits reduces collisions and saves lives.”

A candid view

So far we have learned that the 20mph limit has already been about in small pockets for many years and that everything about it is, according to those promoting it, positive. But like everything, it is not as clear cut as it may seem, and playing the devil’s advocate, to maintain a constant 20mph, without using cruise control, from a car drivers point of view does take a lot of concentration, and there are concerns from some parties that motorists will spend more time concentrating on their speedometers than the road ahead of them.

Much of the wording from press releases or official documents on this subject mention ‘self-policing’ in areas that are 20mph. General observations of the schemes have been that in Central London it is not often possible to get near that maximum speed due to the amount of traffic congestion. In other areas where the 20mph has been long standing, such as St Giles in Oxford, it is generally ignored, unless a marked police car is watching the traffic and looking for those breaking the limit; and when the police do watch, they are extremely busy pulling multiple motorists over and giving them a ticket.

The reality is that if these 20mph limits and zones are to be taken seriously, they need to be policed in the same way that other roads are; we have experienced tailgaters at 30mph, and driving in some of the rural areas that now feature the 20mph brings a new meaning to the term. Those that are unable to stick to 30mph in a town centre seem to find 20mph in the country impossible.

Cost is another issue for local authorities to consider, Road signs and markings do not come cheap in the year 2023, and changing every speed limit sign, and putting up duplicate repeaters signs takes a huge amount of their budget, especially when you consider that Birmingham City Council has recently declared that it is bankrupt and has halted all spending except for essential services.

We are in a period where central Government is still cutting local authorities’ budgets, and they have to find ways of saving money, a path we have been down many times before in the public transport sector.

Challenges for bus manufacturers

With the 20mph speed limit on the rise, bus manufacturers, and in particular gearbox manufacturers, have a new challenge. “Whilst the speed limit is nothing really new for Central London, the provinces are a different story. Although electric and hydrogen buses don’t have the issue of multiple gears, a low-revving Euro VI diesel bus could find itself in in second or third gear at 20mph, meaning that the engine is not getting hot enough to burn off the soot deposits from the exhaust system if the vehicle is not venturing beyond these zones.

An operator in South Wales has already, reportedly, experienced issues with Euro VI buses and constantly having to clean blocked soot traps, and so has reverted back to Euro V-standard buses.

It is too early to know how services like the TrawsCymru T1C, which takes over four hours to get from Aberystwyth to Cardiff, via many rural communities which are now 20mph, will be affected. RICHARD SHARMAN

Welsh Government perspective

Wales became the first part of the UK to introduce a nationwide 20mph speed limit on most residential roads, which currently have a 30mph speed limit, from Sunday 17 September. The Senedd passed the legislation to bring in the new default speed limit across Wales by an almost two-thirds majority. Approximately 35% of the roads in Wales by length will become 20mph.

Under the new 20mph legislation, local councils can use their local knowledge to retain a 30mph limit where there is a case for doing so. These 30mph roads will be marked by signs in the same way that variations from the current default speed limit are used.

Professor Stuart Cole CBE, Emeritus Professor of Transport Economics and Policy at the University of South Wales, writing for says the new default 20mph speed limit will mean significant cost implications for operators through increased drivers’ hours and less efficient vehicle operation, “in much the same way as traffic ‘humps’ on bus routes cause increased wear to vehicle suspension and fuel consumption with consequent increases in cost.”

“Bus passengers, will have to face longer journey times on urban routes,” he points out, and at a time when resources are already scarce, “companies will require additional vehicles and driver shifts if the current bus service frequency is to be maintained. Increased drivers’ hourly rates, currently under negotiation with the trade unions, will also increase costs.”

A spokesperson for Stagecoach South Wales told CBW: “We support steps to deliver safer roads and journeys in our communities. At the same time, it is critical that the Welsh Government pursues a set of transport policies that work together and not in isolation, ensuring there are no unintended consequences that undermine other objectives.

“The best way to ensure the safety of pedestrians and road users, as well as delivering smoother and faster journeys for bus passengers and protecting the long-term sustainability of greener bus travel is by ensuring that buses have priority on road infrastructure over cars. There are no planned changes to services at present but our teams continue to monitor our routes and any changes will be shared via our usual communication channels.”

A spokesperson for Arriva Wales told the Daily Post that: “Arriva continually reviews our timetables and we plan to monitor our services once this change is implemented. We will see what or if any impact it has on our services and adjust journey times if needed.”

Chris Owens of Alpine Travel also spoke to the Daily Post and said: “It is very difficult to make any accurate calculations because average speeds for school buses along built up roads is very rarely higher than 20mph due to the volume of traffic at home to school travel time. So, any impact will be marginal, although timetables may need changing in due course.”

He said there may be a need to amend the algorithms used to calculate journey times on the Conwy Fflecsi network, and added: “These journey times are calculated quite accurately using tracking data to ensure that passengers know what time to expect to be collected on these demand responsive services operated on behalf of Conwy County Borough Council and Transport for Wales.”

First Cymru told customers: “We’re not anticipating that the new 20mph speed limits will have a significant effect on our services – 91% of our routes are scheduled to operate below an average speed of 20mph. But, we will monitor performance data across all of our routes in the coming weeks and months. If our data suggests that a timetable needs to be amended to remain punctual, we will make the required changes and communicate these changes accordingly.”

Arriva Wales said that it will monitor journey times of its services. RICHARD SHARMAN

Operator feedback

Whilst bus operators find themselves in a tricky situation when it comes to going against a new speed limit which is promoted by consistently mentioning safety, it can and does defend its position when it comes to consultations on the subject. A good example of this is a March 2023 document produced by Oxfordshire County Council which proposes a 20mph in Woodcote.

Even though Stagecoach does not operate in this area, its Head of Strategic Development and the Built Environment told the council that it has no objection as it does not operate services in the settlements covered: “However, there are other bus operators in Woodcote. The proposals are likely to have some effect on these services, especially when considered cumulatively with those in other settlements along the line of what is a strategically significant and lengthy interurban route group. We would therefore urge the Council to pay particular attention to other operator responses. Material increases in service running time in rural areas can have a disproportionate impact on bus operating economics.”

The Business Development & Partnerships Manager for Thames Travel formally objected to the proposals on the basis that “Woodcote is served by the trunk X40 service between Oxford and Reading and also by the school-day only service BB3. Both services have recently had extra running time added with yet further additional running time due to be added to the X40 shortly.

“The new X40 timetable will require an extra bus to be added to the cycle in order to maintain the current frequency. Whilst there will be extra driver and bus costs it is highly unlikely that there will be any additional passenger revenue as the service frequency will remain the same.

“The longer journey times are actually likely to see a reduction in patronage as the service becomes less attractive compared to making the journey by car. In order to minimise the increase in bus and driver costs which result from this we had proposed to withdraw certain evening journeys when fewer people travel.

“We therefore have concerns that further reductions in speeds will make bus services even more unattractive to potential passengers. We have no problem with and support these proposals where they do not affect bus services.”

The operator’s statement goes on to document the changes and affects in high detail.

Many bus operators support the 20mph limit benefits, but also acknowledge the fact that they will potentially slow bus journeys down and in many case require additional resources to be added to services to ensure a certain frequency is maintained, which all costs money.

The bus operators’ landscape continues to change at a rapid pace, be it changing running cards or timetables to ensure electric buses can do a full day without being charged, or adapting to slower journey times and a potential increase in a depot’s peak vehicle requirement due to this new speed limit. I am sure operators nationwide will be watching Wales with great interest, as local authorities continue their roll out of the 20mph limit to other areas of the UK.