FAQs about a borough-wide 20 mph speed limit

1. Is it safer to drive at 20mph?

Yes. According the Royal Society for Prevention of Accidents (RoSPA) if a pedestrian is hit by a vehicle travelling at 20mph there is a 2.5% chance that they will be fatally injured, compared to a 20% chance at 30mph. Slower speeds not only reduce the severity of injuries, but also the chance of a collision (road traffic accidents) occurring as people have more time to react.


2. Will there be fewer collisions as a result of the scheme?

That is what we expect. Research by the Department for Transport (DfT) shows that a 1mph reduction in speed results in a 6% reduction in collisions. So, even a modest reduction of 1mph average speed would result in 37 fewer collisions a year in Camden (based on an average of 580 collisions a year (data from 2012). In Portsmouth, vehicles slowed on average by 1.3mph and collisions reduced by 21%. A similar result in Camden would mean over 100 fewer collisions a year. 


3. What if traffic speeds do not reduce?

The borough-wide limit is not the ‘final chapter’ but rather the start of a new approach in the borough. It should be noted that a large part of the borough is already subject to 20mph and this scheme simply extends the limit to the remaining borough roads. This will create a consistent limit and reduce driver confusion. The Council will continue to have an extensive road safety engineering programme to implement measures targeted at specific locations where speed and casualties continue to be a problem, rather than the traditional area wide traffic calming that has been used in the past.

The Council does not expect everyone to drive within the 20mph limit from the outset, but over time, compliance will increase.  The borough-wide limit, which is in line with Islington’s limit and those proposed in other boroughs (for example the City, Southwark and Haringey) is also expected to bring about a culture change over time where it becomes ‘socially unacceptable’ to drive more than 20mph in an inner London borough such as Camden, in the same way as breaking 30mph in town centres, drink driving or not wearing a seat belt currently is.


4.  How much will it cost and is it worth it?

The cost benefit of the scheme is potential very good. The final cost of implementing the scheme in Camden will be approximately £300K. Even the most conservative speed and accident reduction assumption (1mph = 6% less accidents) has an effect that could justify the cost of the scheme. Based on an average of 580 collisions a year (data from 2012) a 6% reduction would represent 37 fewer few collisions. Taking the average cost of a collision as £68,320 (DfT 2010), this equates to a monetary benefit of £2,527,840 per year saving to society (which includes things such as costs to the emergency services and NHS, insurance claims, and state support and loss of productivity during periods of sick leave etc).

There are also significant financial savings (e.g. costs to the NHS) that will come with the health benefits if more people chose to walk or cycle as a result of the scheme, because these people will have more active life styles. Air quality will also improve if there are fewer people driving.  The economic benefits of improving streets for pedestrians by reducing the dominance of traffic and improving road safety have also been well documented (see Paved with Gold by CABE).  There are no cashable benefits to the Council, however this new approach will be much more cost efficient over time than the previous programme of rolling out 20mph zones and limits area due to economies of scale and more targeted traffic speed.

5. Will the decreased speed limit affect my journey time?

Inevitably some journey times for some people will increase (note that journey time is different from congestion) but only slightly and the disadvantage to drivers is considered to be far outweighed by the road safety benefits. The increase in journey time is also expected to be small in reality. 

6. How much do you expect cars to slow down by?

Based on similar schemes in other areas we expect vehicles to slow down on average by 1-2 mph. It takes two minute to travel a mile at 30mph and 3 minutes at 20mph, however this is at constant speed. Most of the time traffic is actually below 20mph in the borough due to the number of junctions, traffic lights, congestion, road side parking, traffic calming etc. Schemes implemented by other authorities show that the higher the average speed on a given road, the greater the level of speed reduction up to 6-7 mph.

7. Who will enforce the new speed limit?

The Met Police are responsible for enforcing speed limits in London. However, due to very limited police resources, the Council is not relying on enforcement by the police for the scheme to be successful. The Police expect Camden to create an appropriate environment which will raise awareness of the scheme to drivers, for example through signage and physical measures, as well as road safety education and promotional campaigns. Camden will undertake regular and extensive speed surveys around the borough to measure the effectiveness of the scheme and consider additional measures where speeds continue to be excessive. The police will target locations where there are persistent high end offenders.

8. Will there be more speed humps?

We have not implemented speed humps as part of this scheme. However, we will continue to consider traffic calming measures, particularly in residential areas, where there is a high level of road casualties, when they are requested by the community, or where speed continues to be a problem as shown in our surveys. If speed humps are necessary at specific locations consultations will be carried out in the normal way as part of a new and separate proposal. Existing speed humps will not be removed as part of the new 20mph limit implementation. 

9.  Will businesses be affected by a speed limit? 

Restricting the movement of people and goods may be an issue for the local economy, but slower speeds help to reduce the dominance of traffic and therefore contribute to a more pleasant environment for high streets. Officers have not found any evidence that 20mph schemes in Europe have damaged or improved local economies. However, according to research by Living Streets (The Pedestrian Pound, Living Streets, 2013), improving the environment for pedestrians in particular (including making it safer), does reap economic benefits for local businesses. 

10. I support a 20mph speed limit near schools, but aren’t there already slower speed limits in place around schools in Camden?

There are many schools throughout the borough, but not all of them are located in 20mph zones or limits. Camden Council prioritises road safety for vulnerable road users, such as children.  We want to encourage children to walk to school and to make it as safe as possible for them to do so. School children often have to cross main roads to get to schools as Camden has a large number of schools that are spread right across the borough. 

11. Which roads are included in the speed limit?

All roads managed by Camden are included in the borough-wide limit. The Transport for London Road Network (TLRN) ‘red routes’ are not included in the new limit (other than a section of Camden High Street which is already 20mph). Some red routes may be added over time, subject to ongoing discussions with Transport for London (TfL).

Boundary roads shared with neighbouring boroughs are not included in Camden’s borough-wide limit. The boundary road with Islington is already part of an experimental borough-wide 20mph limit implemented by that borough, which will now become permanent. Other boundary roads may be added at a later date if neighbouring boroughs consider implementing their own borough-wide 20mph schemes, or as part of a specific area scheme being undertaken jointly between Camden and a neighbouring borough.  

Private roads or those on housing estates are not included in the borough-wide limit.

Many of Camden’s roads are already covered by a 20mph limit and these will remain although the signage has been reviewed to be consistent with the borough-wide scheme.


12. Why are red routes not included in the borough-wide 20mph limit? 

London’s ‘red route’ network is managed by TfL, not Camden Council. TfL has said that it may consider changing the speed limit to 20mph on these routes on a case by case basis – and has done so on Camden High Street as part of a separate scheme.  We will work with TfL to make improvements on the ‘red routes’, based on views submitted as part of the public consultation, as well as other considerations such as casualties and the function of the street.

13. Which roads are managed by Camden Council and which roads are ‘red routes’?

‘Red routes’ in Camden, which are roads managed by TfL (also called the Transport for London Road Network or TLRN).  Camden Council does not have the power to make changes, such as changing the speed limit, on these roads.  Camden Council managed roads do not include private roads or roads on housing estates.

14. Where do the majority of road casualties occur in the borough? 

80% of road casualties in Camden occur on main roads such as high streets, main through routes, corridors and busier streets which carry more traffic, including buses.

15. Will there be more speed cameras?

No. The criteria for installing speed cameras are set by the London Safety Camera Partnership. The criteria states that cameras may be used at locations where there are at least four collisions which resulted in a fatality or serious injury (KSI) over a three year period. These collisions must have also occurred within a 500m stretch of road, and two of them must be considered to be as result of vehicles travelling too fast. 

Funding for installing speed cameras currently comes from the Mayor of London and none will be installed as part of this scheme.

16. Will the scheme affect air quality?

The speed of traffic, particularly in city centres, is not a major factor in air quality. The most important factors are the volume of traffic and types of vehicles being driven, as well as driver behaviour. 

17. Will there be increased congestion in the borough as a result of the scheme?

It is not expected that a borough-wide speed limit would significantly increase congestion. Lower traffic speeds do not necessarily reduce the free flow of traffic and although some journeys may take longer on some roads but we do not expect this to be significant.

18. Is the scheme being used to generate revenue for the council?

No. Only the police are legally able to enforce speed limits and revenue from fines goes direct to Central Government. Neither Camden Council nor the Met Police will generate any revenue from this scheme.

19. How do I know which roads are 20mph?

In line with DfT requirements, there is signage at the borough boundary to indicate to drivers that they are entering a 20mph area. In addition, all streets which are new to the limit or are not part of an existing 20mph zone with traffic calming have repeater signs. Streets within existing 20mph zones with traffic calming remain the same: i.e., the signage to the entry of the zone remain and no signage will be added.  

20. Does the scheme clutter the borough with signs?

Our approach to signage takes account of the fact that much of Camden is in a conservation area. We have sought to minimise street clutter as much as possible.  New 20 mph signs have been placed on existing posts or street lighting columns (lamp posts) where possible, instead of on new posts. We have also aimed to keep ‘repeater’ signs, including road markings to a minimum in accordance with DfT guidance. 

21. Are other boroughs doing something similar?

Yes. The London Borough of Islington has introduced a similar scheme, City of London is proposing to implement a City wide limit during 2014, and Haringey has recently consulted on a borough-wide limit with a decision due in February 2014.  Southwark will also shortly be consulting on a borough-wide limit.  Outside of London, Portsmouth implemented a 20 mph limit across 93% of its road network in 2008. Bristol and Liverpool are implementing similar schemes after successful pilot projects that encouraged more people to walk and cycle, and Birmingham is also now considering a scheme. 

22. Will any parking be lost?

Not as a result of this scheme.

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