Width of Shoulders on National Highways

B. Recently Ministry of Road Transport And Highways, Government of India has asked for comments on the Draft Notification DRAFT No.RW/NH-33044/22/2020-S&R (P&B)  on  the subject: Width of Shoulder (Paved & Earthen) for National Highways– Reg.

C. M/s General Highways And Infracon Pvt Ltd (GHAIPL) has given it's comments on the Draft Notification which is as follows:

Vide reference above comments have been invited for the subject cited issue. In this regards; My suggestion is that, instead of issuing piece meal instructions, the Authorities should do the analyses of the matter holistically keeping in mind the theoretical approach the proposed / revised specifications & dimensions should be decided in such a way that these enhances the safety of commuters, provide forgiving roads keeping in view the habits, behavior of our people and political interferences, sustainability in long terms. The cross-section of the road should consist of adequate space and margin for the safe travel of all types of vehicles (Authorized / Unauthorized). As per my practical experience along with the information collected from literature on Highways I have the following suggestions:-

1. Typical Cross Section :- The complete cross section (dimensions) of highway needs to be revised keeping in view the following:

(a) Mixed traffic on the roads.

(b) Lane driving is not there.

(c) Over speeding & drunken (3-4 pegs) driving.

(d) Parking of vehicles along the outer edge of road for relaxing, urination, Nausea and

discomfort especially on hill roads. Tyre replacement, pick and drop of passengers.

(e) Continuous / intermittent digging of shoulders for laying / replacing utilities. Provision of utilities

in future. Installation of hoardings and sign boards especially by political parties.

(f) Presence of animals on roads.

(g) Frequent openings in median, Authorized / unauthorized.

(h) Wrong side driving.

(i) Quality / durability and quantity of road marking, signs & theft there of

(j) Maintenance of Highways and its allied infrastructure.

(k) Temporary hutments constructed by of people living in low lying areas along highways during

floods. This scene is very common where there is very wide Khadar width of rivers &

meandering. People who has their houses and agriculture land in Khadar width, shifts

temporarily on highways for few months.

Note :- The typical cross section as per Fig. 1 attached herewith is suggested:-

FIG-1 (2 Lane Carriageway)

2. Shoulders

The width of paved shoulders shall be commensurate with safety and functional needs, especially at higher traffic speeds, on access-controlled roads and for the use of slow vehicles.The remaining part of the shoulder may be in the form of verges (unpaved shoulder). Verges should be hardened and stabilized, and may be grassed or laid with gravels/ covered with stone set pavement. Outside built-up areas adequate horizontal clearance (set-back) should be provided for roadside objects including safety barriers with respect to the edge of carriageway and the outside edge of the paved shoulder. This is subject to additional considerations pertaining to shoulder widths, clear zones and vehicle restraint systems.

2.1 The shoulder consists of a paved shoulder and earthen shoulder.

(a) Paved shoulder has a bituminous or concrete surface which is provided to serve the following functions

• Emergency stoppage and temporary parking of vehicles in an emergency for relaxation in case of Nausea and discomfort especially on hill roads

• Usage by emergency vehicles to access incident sites

• Part of the clear zone allowing an errant vehicle to recover

• Use by pedestrians, slow vehicles and low powered motorcycles etc.

• Additional space for roadwork

Note:- In our country the Paved shoulder width (Blacktop / white top) has the same quality of surface and thickness of crust as is for carriageway. Only an edge line (which starts fading soon after painting) is there between the C.W. and paved shoulder. Hence for commuters all black / white top is carriageway, so the paved shoulder does not serve the full purposes mentioned above.

(b) Earthen shoulder / Unpaved Shoulder/ Verges is a hardened and/or stabilized ground surface which may be in earth, grassed or laid with crushed rocks or gravels/ paver blocks forming the remaining part of the shoulder is provided to serve the following functions ;-

Note :- ****

Horizontal clearance (set back) provides additional room to accommodate for:

• recovery from momentary deviation of travel paths

• protruded side mirrors

• opening of vehicle doors in an emergency

• additional margin in case the paved shoulder is used for running traffic or emergency

vehicle

Horizontal clearance is defined relative to:

• Outside edge of the paved shoulder

• Kerbline at the edge of a footpath or traffic island

• Edge line at medians.

The desirable horizontal clearances to serve the above said purposes are

as follows;-

I. With paved shoulder = 600mm from Outside edge of paved shoulder

II. Verges without paved shoulder =1200mm from edge of carriageway

III. Towards median =1200mm from edge of carriageway ( It includes kerb shyness width of 500 mm , the balance 700 mm. width towards median should have rough surface like tectile pavement/ paver blocks etc . which discourages the drivers to move near the median barriers , open medians.

NOTE :- SPACE FOR FIXING SIGN BOARDS SHOULD BE PROVIDED AND CONSIDERED WHILE DECIDING THE WIDTH OF SHOULDERS. As in most of the cases there is hill on one side and deep valley on other side. It has been practically seen that the sign boards are fixed abutting the carriageway / paved shoulder or in earthen shoulder on valley side, which is a serious safety hazard.

3. Space for Drain on Hill Side:- In this regard it is informed that

3.1 Existing Scenario:

a) As mentioned in Para 8.4.6 of IRC:SP:42-2014, 600 mm width is left on hill side for accommodating open drain. The minimum depth of drain is 300 mm (part of it gets filled with sliding muck). This drain abuts the paved edge of road / paved shoulder* (* used as carriageway).

b) Road side drains are constructed to V- shape, parabolic or Saucer Type drain, trapezoidal, Triangular, Kerb and Channel or U shaped cross section as shown in figures under para 2.4.2 of IRC:SP:48-2023 (Hill Road Manual).

c) As mentioned in para 6.2.2 of IRC:SP:84-2019, the road side drains shall not pose any danger to traffic, slopes of cutting, embankment, pavement of structure. Further in para 6.2.4 it has been mentioned that the side slopes of the unaligned drain shall be as flat as possible and shall not be steeper than 2(H):1(V). Para 6.4 (Drainage of High Embankment) of IRC:SP:84-20194. & para 4.9 of IRC:SP:42-2014 must be kept in mind.

d) The shapes of open drains, constructed in 600 mm width, does not have traversable slopes. These open ditches and channels may cause an errant vehicle fall in the ditch which cause damage to vehicle and passengers as well. The minimum space required to fit side drain with traversable fore slope should be worked out from Fig 10 provided in IRC:119-2015. Reference may be made to Fig. 4.31 of Hill Road Manual.

e) For the safety of commuters horizontal clearance between the start point of slope of drain and the outer edge of the paved shoulder should be provided. To avoid the erosion of surface of this clear space, it can have stone set pavement from locally available stones, it can be treated with coir / jute blanket as mentioned in para 2.4.3.3 of IRC:SP:73-2018.

3.2 Suggestion:-

Safer ditch profiles with shallow depth, gentle side walls and rounding of edges should be provided .The fore slope shall not be steeper than 1:4 so that it is easily traversable by errant vehicle .Ref Fig 2 attached herewith.

(i) For the safety of commuters horizontal clearance between the start point of slope of drain and the outer edge of the paved shoulder in the form of unpaved / earthen shoulder/ verge / clear space should be provided. To avoid the erosion of surface of this clear space, it can have stone set pavement from locally available stones .it can be treated with coir / jute blanket as mentioned in para 2.4.3.3 of IRC:SP:73-2018.

(ii) In case above said provision could not be considered the other option is that * the paved shoulder should be made more conspicuous by changing environment. It may be achieved by providing stone set/paver block pavement as shown in Fig.3, reference may be made to Fig. 5.6 of Hill Road Manual also. This change foster appropriate traffic speed and behavior of Road User. The tactile paved shoulder will be more conspicuous. It will forewarn errant vehicle and guide them back to main carriageway. At the same time, it will be used by emergency vehicle temporary parking and opening of vehicle door in an emergency. The tactile paved shoulder will be safer for pedestrian and slow moving vehicle than bituminous or concrete paved shoulder. Stone set/paver block paved shoulder is economical and requires low maintenance cost. Some stones may be painted with retro reflective paints which to make it more conspicuous during night time this paint will remain permanent and will enhance the safety. Similarly, it is also suggested that gore area should also be constructed of tactile pavement for above mentioned benefits. * This provision can be considered for other paved shoulders also.

(iii) Leave a margin of about 2000 mm instead of 600 mm for side drain to have traversable slope, as per Figure provided in IRC:119-2015. To avoid fixing of safety barrier between drain and paved edge of shoulder.

Fig-2

Fig-3

Fig 3a

4. Median Central Reserve :- In this regard it is hereby submitted that

4.1 :- Existing Scenario:-

(i) As per standard definition the median width is the space between both internal edges of carriageways, this includes paved with of about 500 mm on both carriage ways plus raised / depressed portion median. In day to day use the raised / depressed portion is considered as median width, the specific dispute arises when it comes to treatment of narrow median which is mentioned as 2 m. or less. As per above definition median width of 2.5m, which comprises of paved road 2x.50= 1.0 m as kerb shy plus raised median of 1.5 m / Concrete crash barrier 610 mm plus verge on both sides, is not a narrow median, whereas from safety point of view of treatment it is a narrow median as the balance space between two carriageways is 1.5 m. only.

(ii) When RCC Crash barrier is provided between two carriageways the space occupied at base, by crash barrier is 610 mm only, the balance space out of 1.5 m is paved using the same material as is for carriageway. This reduces the clear space.

Suggestion:-

(i) The word median width be clearly explained, and in case of narrow median with , it should be width between paved edges of road including width for kerb shy / raised or depressed portion of Median.

(ii) The balance verge i.e width left after erection of New Jersey Barrier in median should be provided tactile pavement (Stone set/paver block) . Refer Fig. 4 & 5 enclosed herewith

4.2 Fixing of Light poles in case of narrow medians :-

Existing Scenario:- It has been observed that the New Jersey Barrier is discontinued at every 15/30 m. for inserting Electric light pole . The shape of New Jersey Barrier changes at this location and technically it gets discontinued at this location.

Suggestion :- The New Jersey Barrier shape and size should not be disturbed/ changed Proper lined sketch for Installation of electric poles on New Jersey Barrier be issued, to avoid discontinuity of New Jersey Barrier, reference may be made to the Fig.6a & 6b prepared from www.ftp.dot.state.tx.us

4.3 Opening in narrow Median :-

Existing Scenario:- In case the median width is less than 5 m. which is very common case in most of the brown field projects/ Hill roads , storage lane widths are not provided at location of median openings as this is not specified in any manual / code . The practice is to provide median opening with blinkers ……, these locations are serious safety Hazards.

Suggestion:- The provision as shown in Fig. 7a-c should be made mandatory in relevant codes/ manual. As per this Fig. the median width is increased from 1.5 m to 5.5 m, by providing proper transition thereafter a storage lane is provided for standing and turning of vehicles. This provision can be accommodated within roadway width of 28.50 m. This arrangement is similar to the shown in Fig. 3.1 & 3.2 of IRC:SP:73

Fig-4

Fig-5

Fig-6a

Fig-6b

Fig-6c

Fig-6d

Fig-6e

Fig-7a

Fig-7b

Fig-7c

Fig-7d

5.0 TCS of Bridge / Width of bridge at deck level and location of RCC Crash barrier between Main carriageway and foot path :-

As per TCS for bridges with footpath provided in various manuals / codes a RCC Crash barrier is proposed between footpath and carriageway on outer edges and in case of two separate bridges a RCC crash barrier is proposed abutting the paved shoulder edge. This standalone crash barrier fouls with the free flow of traffic approaching the bridge, many accidents have happened on this account. In the draft letter the width of bridge has been increased as shown in Fig 3,4,6 & 7 of MORT&H letter. To sort out the above said safety issue. My comments and suggestions in this regard are as follows:-

Comments :- It has been specified in the manual that all new structure shall be designed for the condition when footpath is used as carriageway. The overall increase in width of Bridge deck will change the lane configuration for structure design purposes as provided in Table 6 of IRC ;6-2017, it will increase the cost of structures.

Suggestion:- (i) Do not increase the width of deck slab as suggested in draft , Maintain the minimum width of deck slab equal to or more than the formation width of approaches (Paved surface + Earthen shoulder + thickness of RCC Crash barriers at both edges) i.e. the inner edge of crash barrier should match with the outer edge of earthen shoulder / verge. In case of isolated standalone bridge where pedestrian flow is not expected; Do not provide crash barrier between foot path and carriageway, Propose RCC Crash barrier at outer edges of deck.

(i) The surface of 1.5 m. width designated as footpath should be differentiated from blacktop/ carriageway by way of providing different finishing

(ii) A mountable kerb may be installed to separate carriageway and footpath / raised pavement marking with studs may be provided instead of mountable kerb.

(iii) Surface of footpath may be made tactile.

6.0 Width of culverts:- 

It is ok as suggested in 3D Figures , however at the location of merging of side drain with culvert the width of culvert should be increased as shown in Fig. 8.

Fig-8a

Fig-8b

7. Type & Height of RCC Crash barrier installed at both edges of structures:-

Existing Scenario:- RCC crash barriers with clear height of 900 /1100 mm above FRL are provided on both edges of Elevated structures. In the recent past it has been observed that some vehicles had over toppled these crash barriers.

Suggestion:- High containment crash barrier with height 1550 mm, as Per Fig. 5 of IRC 5 should be made mandatory for the location in builtup areas and on all horizontal curves.(Fig. 9 attached)

Fig-9a & Fig-9b

D. I have tried my best to convey my view point in above paras, but many more suggestions

may be there for further improvement in this regard. You are free to contact me for detailed

discussions at my phone No. +91-981417500, mail id:- md@theghai.com

Give your Comments Below or If you want to be anonymous then send your comments on ho@theghai.com

Comment on Width of Shoulders on National Highways