IRC 99-1996 Speed Breakers

8/12/2019 IRC 99-1996 Speed Breakers

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IRC 988

TENTATIVE GUIDELINESO

THE PROVISION OF SPEEDBREAKERS FOR CONTROL

OFVEHICULAR SPEEDS

OMINOR ROADS

THE INDIAN RO DS CONGRESS996


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IRC : 99-1988

TENT TIVE GUIDELINESONTHE PROVISION OF SPEEBRE KERS FOR CONTROL

OFVEHICUL R SPEE S

ONMINOR RO DS

uhlished byTHE INDIAN ROADS CONGRESS

.Jarnnagar lloust-, Shllhjah:lll Ruacl,New l>t lhi-llU OllI9

Price R: . 32Plus packing. rostagd


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IRC 99--1988First published Janua ry, 19881\f'P 'I?d IW:Jy, 1Q8QHcpnntcd : Janu:u y. 9CJ6

Tht ights of Publication and of Translation Jre reserved)

l r t l l l ~ : d at M/l> Sagar l nntcrs t v. Publishers. ew Dt:lhi - l I 0001( ) ) ) cnpH.:s)


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IRC: 99 1988

TENTATIVE GUIDELINES ON THE PROVISION OF SPEED BREAKERSFOR CONTROL OF VEHICULA R SPEEDS ON MINOR ROADS

I. INTRODUCfiON1.1. Development f suita blc recom mendati0ns on speedbreakers have been under the consideration of the Trallic Engineering Commmee of the Indian R o a d ~ Cungrc:ss for some trme. TheTraffic Engrneering Cl mmattee 10 their mcctang held at Bhopal onthe 4th February. 1986 entrusted th e


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JRC 99-19881.2. The revised draft was considered by the SpecificationsStandards Committee in their meetmg held on the 9th November,1987. The Committee authorised S/Shri J.B. Mathur, D. Sanyaland K. Arunachalam to jointly modify the draft in light of thecomments of th e Specifications Standards Committee.1.3. The draft : s revised was approved by the ExecutiveCommittee in their meeting held in New Delhi on the 13th November, 1987. Later on, the document was placed before th e Co uncilin their 12l >t meeting held at Trivandrum on 6th December, 198 7.Th e Council approved th e document subject to some minor changeswhich have since been incorporated.

2. GENERAL2. I. Roads of different ca tegories and under different situtions are designed for designated design speeds at which vehicles

c n trave l with convenience nnd sufety . However, at cc rtuin Joeations, such as approaches to manned and unmanned level erossings, sharp curves, congested{accident-prone locat ion s, res id entialstree ts, etc., control of speed may become r1ecessary to promoteorderly traffic movement and improved safety..2.2. A number of engineering measures are available to control vehicular speed. Some of these are pos ting of mandatoryspeed limit signs, use of ashing beacons to alert drivers. roadmarkings of various tyres, etc.2.3. Yet , there may be cases, particularly on secondary/tertiary roads an d on residential stree ts in urban areas, where certnin physical constraints may become ne cessary for effecting control on ve hicu la r speeds. In this regard, th ree types of devices,namely, speed breakers, rumble strips and width restrictions have

beert used successfully . Choice among these will depend on loca lfactors such as the type of area traversed, the type and volume oftraffic, the extent of speed reduction desired, and other local factors. Ho\\oever, speed breakers, in particular, are meant mainlyfor residential areas, minor roads, and similar situ ati ons. Theiruse on major inter-city roads outsid e urban areas is not considereda good engineering practice, and the Indian Roads Congress doesnot fav our it.2.4. Speed breakers, where permitted to be in stalled, provide visua l, audible and tactile stimuli which alert drivers and causethem to slow down. These ca n have different heights, lengths,spacings, signs, etc. In fa ct, no particular design is suitable for all

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IRC: 99 1988the types of vehicles using the road. For example, a speed breakerdesigned for trucks can be dangerous to motor cyclis ts and onedesigned for motor cycl1sts will be metfcctjve for trucks. The design recommended herein IS a compromise design to suit averageIndian road traffic condit1oos and is based on field investigationsand research.

2.5. Speed breakers are not intended as substitute for pro-per mandatory, warning or informatory signs but arc meant on lyto draw attention of driver:. to a possible hazard ahead.2.6. These recommenJat10ns may require revision in thelight of future experience and development in th e field. Towards

th1s end, it is suggested that a record of speed and accident conditions, before and-after the mstallatioo of speed breakers, should bekept.3. DEFINITION

A speed breaker is a hump surface across the roadway having a rounded shape with width greater than th< wheel base ofmost of the vehicles using the road. When there is decreased variation in sensory stimuli and at locations where speed con trols aredesired, a speed breaker acts as a strong stimuli to arousereactio n in the brain. Smce the driver reaction times are faster in response to audible and tactile stimuli than to visual stimuli,a driver subconsciously reduces his speed. An ideally designedhump should satisfy the f o l i o ~ ing requirements:

i) There should be co damage to vehicles cor excessive discomfort tothe drivers and passengers whee passing at the preferred crossinaspeed.ii) The hump should not aive rise to excessive no ise or cause harmfulvibrations to the adjoining buildings or affect the other 1esidents ofthe area.

iii) Above the e ~ i g n speed, a driver should suffer increasing level of discomfort but without losmg directional control and without any vehicle damage) depending oo the extent through which des1gn speed isexceeded.

4. SCOPE~ 1 WarrantsUse of speed breakers IS JUStified pnmarily under the followIllS three Circumstances :I) T-iotersections of minor roads with rural trunk highways, characterised by relatively low traffic volumes on the minor road but very highaverage operating speed and poor sight distances . Su


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IRC: 99.1H82) Intersections of minor roada with major roads, and mid-block aectiooa In urban areas where it is d e ~ i r a b l e to brin4 down tho souda;and

(3) Selected local streets in residential areas, school, colleae or university campuses, hospitals, etc. Also an areas where traffic is observedto travel faster than the r e ~ t u l a t e d or safe aoeed in the area .

4.2. Other places here ~ e may be p ~ e d include :1) Any situation where there is a cooaistent record of accidents prJmarily auributed to the apeed of vehicles e.J. when ba:zardous teelions follow a lona a n ~ e n t approach;

(l) Approacbea to temporary diversions;3) Approaches to weak or narrow bridaca and culverts rcouirin,. speedrestriction for safety;4} On the minor arms of uncontrolled junctions and at railway levelcrossioaa;S) Sharp curves with poor sight distances; and6) Placea of ribbon development, where road passes throuab built-upareas and vehicles travellina at hiah speeds arc a source of imminentdanger to pedestrians.

S DESIGN OF SPE0 BREAKERS5 I. Speed breakers are formed basically by providing a

rounded (of 17 metre radius) hump of 3.7 metre width and 0.10metre height for the preferred advisory crossing speed of 25 km/hfor general traffic, Fig. I. Tr ucks and buses having largerwheel bases may feel greater inconventence on passage at suchhumps. To facilitate appreciable and comfortable passage forlarger and heavier veh1cles (where their proportiOn is quite high)bumps may be modified with J.S metre long ramps (I : 20) at eachedge. Th1s design will also eouble these vehicles to pass the h umpat about 25 kmjb, Fig. 2.

5 2 Jn certam locatJons speed breakers may have to berepeated over a section to keep speeds low throughout. Morebumps may be constructed at regular intervals depending ondesired speed and acceleration/deceleration c h a r a c t e r i ~ t i c s ofvehicles. The distance between one hump to another can varyfrom 100 to 120 metres centre to centre shown in Figs. 3, 4 and 5

6. PLACEMENT OF SPEED BREAKERSli.l. The pattern of placement of speed breakers dependsupon the locntion and tbe type of treatment used. Some of thesuggested locations have already been indicated in Clause 4. At'T' intersections speed breakers should be installed on minor roads

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Aheod Sf9n IAeflectoriMd I[Hump Aheod Sign

Hump heod S 9n

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Fia. 3. RccommCDded plaetmCDt of bumpfbumpa in mid-bloclc section bump marking in cbcquercd patternand sian board locations

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180 ' f 180 ... P U C T O St ~ 120"' i ~ ~ 120 .__ .._j 1

IRC: 99 1988

MA.JOR ROAD

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Fla . 4. Speed breakers at T iotersectlon or railway croulog

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SPUO BAUKfJIIRESTRICTION t:NO SIGH

,( MSTRICTION f O ~L --.;7, A_ . ... l f i '

~ f f ~ p rHUM p HE Ll ISIGN

Fia. 5. Plan of speed breakers on approach to a sbarp curve

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IRC : 99 1981or perpendicular arms about 10 metres away from the inner edgesof major roads. Proper sign boards and markings are requiredto be provided at such locations Figs. 4 and 6. On sharpcurves available sight distances guide the p lacement and numberof speed breakers, Fig. 5 For other situations the Engineer-inCharge should use his ingenuity and judgement.

6.2. To check the tendencies of drivers to avoid speedbreakers and using shoulders it is recommended that the speedbreakers should be extended through the entire width of shouldersupported on a proper base.6.3. For undivided carriageways speed breakers should

invariably be extended over the entire carriageway width including shoulders.6.4. On bridges speed breakers should not be provided.However where frequent accidents have been reported or thebridges are on curves or they a re narrow, either approach musthave two speed breakers each.

7. SPECIFICA:rJON FOR SPEED BREAKERS7.1. Speed breakers are laid by first marking the locat ionof bump on the pavement and marking indents in this area forproper bonding. Surface is then cleared of all dust and looseparticles and a tack coat applied. F o rms of requisite heightsshape and width are then placed and bot premixed bituminousmaterial is poured to the required depth and shape. Forms arethen lifted and the surface tinishe d to required sha pe and edgesrounded by trowel. The premixed material should be well com-pacted before opening to traffic. Allo\\-ance should be madefor compaction, and irregularities should be corrected using

bituminous materials having tine aggregate or by scrapping asnecessary. The material is then allowed to cure before openjngto traffic.7.2. Arrangements for proper drainage of the speed breakersmust be made to prevent formation of ponds and puddles.

8. SIGN POSTING AND MARKING8.1. Drivers should be warned of the presence of speed

breakers by posting suitable advance warning signs. The warn-ing signs Fig. 6 should be of the design HUMP OR ROUGHROAD detailed in IRC : 67-1977 Code of Practice for Road9


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IRC : 99-1988

SPEED T ~0emBRE KER

SIGN DETAILSLateral Placement Left0.60 m on kerbed roads2.3 m on unkerbed roadsMounting Heiaht

2.0 m on kerbed roads1.5 m on unkerbed roadsUse reflective paint or stripSize of b 6 ern or :> em standard)Red strip width 4.5 em or 7.0 emPost 8 em x 8 em x 0.8 em)T -Iron to be painted white and black in alternate 25 em banda

Pia. 6 Recommended hump warnioe alan with definition plate1


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IRC 991988Signs . The sign should have a definition plate with the wordsSPEED BREAKER inscribed thereon and should be located40 m in advance of the first speed breaker. Location of this signis indicated in the illustrations of typical cases contained in Figs.3, 4 and 5

8.2. Speed breakers should be painted with alte rnute blackand white bands as shown in Fig. 3 to give add itional visualwarning. For better night visibility, it is desirable that the markings are in luminous paint/luminous strips. Embedded cat-eyescan also be used to enhance night visibility.9 MAINTENANCE

Care should be exercised to repair the hump at regular intervals and also to rem ove the dust or mud collected on either side ofthe hump. Repainting of markings on the hump is the mostimportant maintenance activity, as this provides an essent1al visualwarning to the drivers.

Documents

IRC 99-1996 Speed Breakers