speed know your limits

Speed: Know your limits

Department for Transport

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Speed:Know your limits

Speed: Know your limits Department for Transport

Britain has one of the best road safety records in the world, which issomething to be proud of.The tablebelow gives a few examples of howmany people are being killed everyyear on roads where many of us takeour holidays (2003 data):

Country Road deaths per 100,000 population

United Kingdom 6Greece 19.3*Italy 11.7Portugal 16.1Spain 13.2Germany 8.3France 12.9*2000 data

This is an impressive record, but wewant to improve on it, and there isstill work to be done to further reducethe number of unnecessary injuriesand fatalities on our roads.That is whyit is necessary to continue to work onpersuading and educating motoriststo be more aware of their drivinghabits and their speed in particular.Whether we are motorists, cyclists,pedestrians or horse riders, all of usbenefit from safer driving.

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Department for Transport Speed: Know your limits 03

So why worry about speed?

The Department for Transportannually monitors traffic speeds ataround 180 sites throughout GreatBritain.The total number of vehiclerecords processed to produce the2003 statistics was about 677 million.

These measurements showed that in 2003:

• 58% of cars, 54% of motorcyclesand 53% of HGVs exceeded the 30 mph limit

• 27% of cars and 36% of motorcyclesexceeded the 40 mph limit

• 57% of cars and 59% of motorcyclesexceeded the 70 mph speed limiton motorways

It is clear therefore that many of usspeed at least some of the time.

If you add to this the fact that if apedestrian is hit at:

• 20mph there is about a 1 in 40 (2.5 %) chance of being killed or 97% chance of survival

• 30mph there is about a 1 in 5(20%) chance of being killed or80% chance of survival

• at 35mph there is a 50/50 chanceof being killed

• at 40mph there is about a 9 in 10(90%) chance of being killed or10% chance of survival,

(Source Ashton and Mackay 1979)

And that if it is estimated that for each1mph reduction in average speed,accident frequency is reduced by 5%;

Then it is clear there is a need toworry about speed because theconsequences of driving too fast are so severe.

Is speed as dangerous asbad driving?

Driving too fast is bad driving. In2003 there were still over 3,000people being killed (that’s nearly 10people every day) and 33,000 beingseriously injured in collisions onBritain’s roads.

Unfortunately speed contributes tothose collisions, deaths and injuries.There exists no precise figure for thecontribution speed makes to causingthe collisions, but analysis of casualtystatistics in Great Britain has shownexcessive speed to be a contributoryfactor in 12% of all injury collisions,18% where there is a serious injuryand 28% of all collisions which resultin a fatality.

It is therefore clear that where there are serious or fatal injuriesresulting from collisions, excessivespeed is more likely to be acontributory factor.

There are those who claim that speedis not a significant factor in causingroad accidents, but that view isdifficult to sustain from either researchor experience.All reliable research intoaccident causation shows that thefactors determining both excessiveand inappropriate speed amount toabout 30% of contributory factors inroad accidents.

To an extent it suits us all to assumethat the effects of speed areexaggerated. Individuals will need totake one conscious decision at anygiven time to, say, buckle up a seatbelt or not drink before driving.

Speed: Know your limits Department for Transport04

What speed it is safe to drive at is acontinuous decision making processand to that extent is a more difficultjudgement to make.

Drivers rightly consider poor lanediscipline, failure to signal, driving too close and other errors to be poor driving.

There is some reluctance to acceptthat driving too fast is also poordriving, but it is and there is a need toalter that thinking.



What is speeding?

Excessive SpeedThis is straightforward; it is exceedingthe posted speed limit.To do so is acriminal offence and, if detected, islikely to result in a fine and penaltypoints on your licence. In the majorityof cases this will be a fixed penaltyresulting in a standard fine and licenceendorsement, but in more serious casesmay result in being taken to court.

It is intuitive to believe that, thefaster you go, the greater is the risk of being involved in a collision; andthis is borne out by the facts.Research (TRL 1998 and 1999) has shown that if an individual drives atmore than 10-15% above theaverage speed of the traffic aroundthem, they are much more likely tobe involved in a collision.

Inappropriate SpeedThis is someone driving within the speed limit but too fast for the road and traffic conditions.It is about judgement, and isextremely important.

Urban roads will be subject mostoften to a 30mph speed limit.Thesewill be high streets with shopperslooking to cross the road at variouspoints, parked vehicles around whichpedestrians might suddenly appear,delivery vans, cyclists and buseswhere people might risk crossing theroad where perhaps they should not.They might also be in the vicinity ofschools, hospitals and where theelderly may be present.These roadsrequire drivers to take account of allthese various factors and drive atappropriate speeds.

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Driving at inappropriate speed is also a real problem on rural roads.Despite only around 10% of driversexceeding the speed limit on ruralroads, over 60% of all car occupantdeaths (drivers and passengers) occuron them.This is because, althoughthe national speed limit applies onthe vast majority of rural roads, it isactually difficult to drive at anywhereclose to the speed limit, but it is stillvery possible to drive too fast for the conditions.

These include approaching a bend orjunction too fast, not negotiatingnarrow roads properly and overtakingwhere it is inappropriate to do so.

Inappropriate speed is also a factorwhere poor weather conditionsprevail and when driving at night.

It is a commonly held belief that, sinceroads have far less traffic at night, it issafe to drive at higher speeds.

However, it is a fact that the averagerisk of an accident per kilometretravelled between 7.00pm and7.00am is double that for thatbetween 7.00am and 7.00pm.



What are speed limits?

A brief history of speed limitsBetween 1865 and 1896locomotives on the highway had to be preceded by a pedestriancarrying a red flag and weresubject to a speed limit of 2mph in cities, towns and villages and4mph elsewhere.

The maximum speed limit was thenincreased to 14mph and again, in1903, to 20mph.

In 1930 speed limits for cars andmotorcycles were abolished.

In 1934 a general 30mph speedlimit was imposed on roads in builtup areas (effectively roads withstreet lighting) which remains tothis day.

Other roads had no speed limits atall. It was not until 1965 that anational upper limit of 70mph wasintroduced for all roads, includingmotorways.

Since 1977 the speed limit for carsand motorcycles on dualcarriageways has been 70mph, witha 60mph speed limit on singlecarriageways.

In 1999 local authorities were giventhe powers to introduce a 20mphspeed limit without requiring theconsent of the Secretary of State.

Vehicle Speed Limits

Different vehicles have differentmaximum speed limits on certaintypes of road. It is for the driver toensure that they know the speedlimit for their vehicle at all times.The speed limit table featuredoverleaf explains the differentspeed limits that apply to differentvehicles.This can also be found inthe Highway Code.

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type of vehicle

cars & motorcycles(including car derived vans up to 2 tonnes maximum laden weight)

cars towing caravans or trailers (including car derived vans and motorcycles)

buses and coaches(not exceeding 12 metres in overall length)

goods vehicles (not exceeding 7.5 tonnes maximum laden weight)

goods vehicles (exceeding 7.5 tonnes maximum laden weight)

Built up area Single Dual Motorways(street lit) Carriageways Carriageways

mph mph mph mph

30 60 70 70

30 50 60 60

30 50 60 70

30 50 60 70*

*60 if articulated or towing a trailer

30 40 50 60

Know your Speed Limits

Speed: Know your limits Department for Transport10

Who has responsibility forspeed limits?

A central body called the HighwaysAgency sets speed limits on themotorway and trunk road network.The Government provides advice totraffic authorities (County, Districtand Borough Councils, but not ParishCouncils) on the setting of localspeed limits. It is for those authoritiesto decide what is the mostappropriate speed limit for their roadsbased upon local considerations andcircumstances.This would usuallyreflect factors such as accident history,traffic flows, road traffic mix, levels ofadjacent development and roadgeometry.They can set speed limitsfrom 20mph to 70mph inclusive.

Speed Limits at Roadworks

Speed limits are often lowered atroadworks.There are valid reasons for doing this.The safety of thosededicated to repairing our roadnetwork is paramount and thereforevehicle speeds will need to belowered where workmen are likely to be present. In addition, thecarriageway will be narrowed to allowwork to progress. Such narrowing willinevitably mean it is appropriate toreduce vehicle speeds. Lower speedlimits will help to achieve this.

Dual Carriageways

There is sometimes some confusionas to what a dual carriageway is,especially for those vehicles restrictedto speed limits below that for cars,such as HGVs and Coaches. In short, adual carriageway is a road that isseparated by a central reservation.Acentral reservation is anything otherthan a pedestrian refuge thatseparates vehicles going in onedirection from vehicles going in theother direction. It should be notedthat although it is more usual to havetwo or more lanes in each direction,the number of lanes is not specified,i.e. it is the presence of a centralreservation rather than the number oflanes that determines whether or nota road is a dual carriageway.

Different Speed Limits andhow to recognise them

20mph Speed LimitThe 20mph speed limit ispredominately used in urban areas.Commonly you will see them in towncentres, high streets, residential roadsand in the vicinity of schools.The aimof this limit is to reduce vehiclespeeds that allows for the presence ofvulnerable road users; cyclists,children and the elderly. More oftenthan not a 20mph speed limit willcome in the form of a ‘zone’.A zonewill contain traffic calming features,usually road humps that force driversto reduce their speed to around20mph. Research on the effectivenessof these zones has shown thatcasualties can fall by up to 70%where they have been introduced.

30mph Speed LimitThe 30mph speed limit ispredominately used in urban areas(and more recently in many villages)and usually is indicated by thepresence of a system of streetlights.The presence of street lights is theway we recognise this speed limit andit is the reason why you do not see,apart from where the limit starts,30mph speed limit signs. Somebelieve this to be an odd way ofindicating a speed limit, but really it issimple. If there are streetlights and nosigns to the contrary a 30mph speedlimit is in force.

There are a number of unlit roadswhere a 30 mph speed limit applies.In these circumstances the trafficauthority must place 30 mphrepeater signs.



40mph and 50mph These two speed limits wereintroduced in the 1970s and arepredominately used in non-built upareas or in built up areas where ahigher speed is both safe andappropriate. In addition to signing thebeginning of the speed limit, trafficauthorities must also place speedlimit repeater signs at regularintervals along the length of roadbeing enforced.The driver shouldtherefore be in no doubt of what thespeed limit is for the road beingdriven on.

The National Speed LimitThe national speed limit is indicated by a round sign showing a whitebackground with a diagonal blackstripe across it. For the majority ofvehicles it means 60mph on singlecarriageway roads and 70mph on dualcarriageway roads (as detailed above,some vehicles are restricted to lower speed limits).This speed limit works onthe same principle as the 30mph speedlimit in that it is not signed apart fromwhere the speed limit starts. It ispredominately used along the ruralroad network.Again, recognising it issimple.Where there are no streetlightsand no signs to the contrary, thenational speed limit is in force.Thespeed limit on a motorway is 70mphunless otherwise indicated.

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But do speed limits make sense?

Most people believe in the need for there to be speed limits; but whodecides? The system may not beperfect but it is not arbitrary.Detailed guidance on setting speedlimits is provided to all trafficauthorities.Their Highway Engineersand Road Safety Officers using theirknowledge and experience will applythe guidance.They will also consultthe police who have the task ofenforcing speed limits.This ensuresthe limits are set appropriately.

Compliance with Speed Limits

In an ideal world all drivers would obey all speed limits at all times.Unfortunately we do not live in anideal world and for any number ofreasons drivers do from time to timefail to stick to the posted limit.

Over the years a number of measureshave been developed to help driversstay within the speed limit in force.These measures have the effect ofchanging the nature or appearance ofthe road to encourage drivers that aslower speed is appropriate. Localauthorities have all the necessarypowers to introduce any measurethey deem appropriate, but obviouslywhich one would depend on thenature of the problem.

Road humps are the most commonlyused and most effective measure,reducing speeds by up to 10mph.

They are most effective on urbanroads, around schools and in residentialareas.They are not usually appropriatefor rural areas. Other measuresinclude build outs or chicanes thatnarrow the road thereby encouraginglower speeds, or road markings thathave the visual effect of narrowingthe carriageway.

Where there is a need to warn driversto reduce speed when approaching ahazard, vehicle activated signs haveproved to be very effective.These aresigns that remain blank until a vehicleapproaching at a certain speed triggersa message to be displayedelectronically.These signs can be veryeffective on rural roads where thenational speed limit applies but driversneed to slow down considerably totake account of a crossroad, a sharpbend or other hazard.



Enforcement

Ideally, all drivers obey the speed limitin force.And where compliance is anissue, some form of interventionmeasure, such as traffic calming orroad realignment would be introducedthat persuades drivers to adhere to theposted limit.

However, there are roads wherethere is a history of accidents butwhere conventional traffic calmingor other forms of persuasion areunsuitable or have provedineffective. On these roads theremay be no alternative but to providean increased level of enforcement.

The most common form ofenforcement is safety cameras.The purpose of cameras is to deterspeeding at sites where speed related accidents have occurred,not to catch drivers speeding.

The police are responsible forenforcing the speed limit and mayuse any Home Office approvedequipment.Apart from traditionalfixed speed camera housings, thethree most common ways to enforcespeed limits are:

a) in-car speed measuring systemsoperated by a police officer,which measure the averagespeed of a suspected speedingvehicle over a given distance.

b) handheld speed measuringequipment where a police officermeasures the speed of passingvehicles with a ‘radar gun’.Thatofficer will work in tandem with acolleague, positioned further alongthe road concerned, who will beresponsible for stopping anyoffending vehicle and informingthe driver of his speed; and

c) portable speed detection deviceswhich are trained across a roadby a supervising officer tomeasure the speed of anyvehicle going through the ‘line of sight’ of the device.A second ‘stopping’ officer canpull over a speeding vehicle if so requested by the officermonitoring the device.These devices may also havephotographic recording ability,allowing the police to sendnotifications and requirementsto the registered vehicle keeper.

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Changing Attitudes

There are various reasons why people speed.

Some are simply excited by drivingfast.They can be easily affected bymotoring magazines and programmesthat highlight the top performancelevels of some vehicles.

Motorists in general simply regardthe breaking of speed limits – at leastin a minor way – as not a very seriousmatter.Those caught speeding areconsidered to be ‘unlucky’. But theconsequences of driving too fast canbe very serious. Being involved in acollision can result in death orserious injury.

Successive governments have settargets to reduce road accidentcasualties and it is clear that,increasingly, these cannot beachieved without reducing thenumber of people killed or injured asa result of speed. Long term publicitycampaigns are aimed at makingdrivers and riders aware of thedangers of excessive and inappropriatespeed and the substantial safetybenefits that can be gained by evensmall reductions in speed.



In brief:facts and figures

Because the dangers are so severe, a numberof measures have beendeveloped to persuadedrivers to slow down.These measures are not always popular but nevertheless they do work.

20mph Zones and Limits20mph Zones-Average speeds withinzones reduce by 9mphand accident frequencyreduces by 60%

-Overall reduction inchild accidents = up to 67%

-Overall reduction incycle accidents = up to 27%

-Traffic flow withinzones reduced by up to 27%

(Source TRL Report 215 -“Review of Traffic CalmingSchemes in 20mph zones”)

20mph Limits-Speed limit signingwithout supportingtraffic calmingmeasures reduction ofan average of 1mph.

(Source TRL Report 363 -“Urban Speed ManagementMethods”)

Road Humps-Road humps in theirvarious forms achievedthe biggest meanspeed reduction (basedon a mean speedbefore traffic calmingof 30mph)

-100mm high raisedjunctions (Commonlyknown as speed tables,these are large flattopped humps thatstraddle the entirejunction.) achievedbiggest reduction of up to 12mph andsubsequent likelyaccident reduction of 60%.

-75mm high flat-toproad humps and 80mm high round-top humpsachieved a 10mphspeed reduction and alikely accidentreduction of 50%.(Departmentrecommends 75mmroad humps asachieving best speedreduction with leastnegative impacts).

(Source TRL Report 482“The Impacts of trafficcalming measures onvehicle exhaust emissions”)

Vehicle Activated SignsVehicle activated signsare predominately usedin rural areas.They arean electronic sign thatflashes a message to thedriver if a predeterminedspeed has been triggered.Research has shownthem to be veryeffective at reducingspeed and collisions athazards such as sharpbends and junctionswith poor visibility.

They are also sometimesused to remind thedriver of the speed limit in force.Theireffectiveness can bebroken down as follows:

-Mean speed reductionsat speed limit roundelsigns of between 3-9mph

-Mean speed reductionsof up to 7mph atjunction and bendwarning signs

-Mean speed reductionsof up to 4mph on safetycamera repeater signs

-Overall one-thirdreduction in accidentsat trial sites (Norfolk sites)

(Source TRL Report 548 -“Vehicle Activated Signs - a large scale evaluation)

CamerasEffects on casualties atcamera sites:

-A 40% reduction in thenumber of people killedor seriously injured (KSI)

-870 fewer KSIs peryear, including over100 fewer deaths

-a 33% fall in injuryaccidents – 4,030 fewer per year

-35% reduction inpedestrians killed orseriously injured

Effect on speed-average speeds at allnew sites fall byaround 7% or 2.4mph;

-average speed at urbansites fall by around 8%

-the number of vehiclesspeeding at new camerasites drop by 71%

Other findings-79% of people askedsupport the use ofcameras to reducecasualties

-the benefit to societythrough casualtiessaves about £221million per year

(Source:The NationalSafety Camera ProgrammeThree-year evaluationReport - June 2004)

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For further information on Speed and other roadsafety issues you can visit theTHINK! campaign website at:www.thinkroadsafety.gov.uk or for information covering theDepartment of Transport as awhole visit www.dft.gov.uk

Printed in the UK December 2004 on paper containing 80 per cent post consumer waste and 20 per cent TCF pulp.

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