ICS 93.080.10  
 
Reference number  
DRS 267 -2: 2021  
© RSB 2021  
  
 RWANDA 
STANDARD  DRS  
267-1  
 
Second  edition  
2021 -mm-dd 
Feeder roads — 
Part 2:  
Guidelines for maintenance  
 
   
DRS 267 -2: 2021  
©RSB 2021  - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2021  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw   DRS 267 -2: 2021  
iii                ©RSB 2021  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Symbols (and abbreviated terms)  ................................ ................................ ...............................  1 
5 Maintenance  ................................ ................................ ................................ ................................ .. 2 
5.1 Condition assessment  ................................ ................................ ................................ .................  2 
5.2 Typical roads defects  ................................ ................................ ................................ ...................  2 
5.3 Maintenance management  ................................ ................................ ................................ ........  13 
5.4 Scheduled maintenance  ................................ ................................ ................................ ............  14 
5.4.1  Recurrent/routine maintenance  ................................ ................................ ................................  14 
5.4.2  Periodic maintenance  ................................ ................................ ................................ ................  14 
5.4.3  Emergency/urgent maintenance  ................................ ................................ ...............................  15 
5.4.4  Practical aspects of maintenance  ................................ ................................ .............................  15 
5.5 Safety aspects  ................................ ................................ ................................ ............................  16 
 DRS 267 -2: 2021  
©RSB 2021  - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepared by Technical Committees and approved by Rwanda Standards Board (RSB) 
Board of Directors in  accordance with the procedures of RSB,  in compliance with  Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards. Final Draft Rwanda Standards adopted 
by Technical committees are ratified by members of RSB  Board of Directors for publication and gazettment as 
Rwanda Standards.  
DRS 267-2 was  prepared by Technical Committee RSB/TC 009, Building materials and civil engineering . 
In the preparation of this standard, reference was made to the following standard:  
1) Rwanda Feeder Roads Standards - RFRS/Vr_14/05/07_BL - Final Report  
2) BS 1377: 1990 Methods of test for Soils for civil engineering purposes — Part 9: In -situ tests  
3) IS 2720 Methods of test for soil — Part 16: Laboratory determination of CBR  
The assistanc e derived from the above source s is hereby acknowledged with thanks.  
This second edition cancels and replaces the first edition (RS  267-2: 2015), of which has been technically 
revised.  
RS 267 consists  of the following parts, under the general title Feeder  roads : 
 Part 1: Guidelines for design  
 Part 2: Guidelines for maintenance  
Committee membership  
The following organizations were represented on the Technical Committee on Building materials and civil 
engineering  (RSB/TC 009)  in the preparation of this standard.  
Institution of Engineers Rwanda  
Ministry of Infrastructure (MININFRA)  
NPD Ltd  
Rwanda Transport Development Agency (RTDA)  
Rwanda Public Procurement Authority (RPPA)  
TECOS Ltd  
University of Rwanda -College of Science and Technology (UR -CST)  
Rwanda Standards Board (RSB) – Secretariat  
 DRS 267 -2: 2021  
v                ©RSB 2021  - All rights reserved  
 Introduction   
Road is one of the transport infrastructure which facilitates local and international exchange of goods and 
services. Adequate transport of agricultural products between differe nt parts of the country contribute s to the 
socio -economic development of local population through easy access to markets , modernization and 
commercialization of agriculture, creating possibilities  for transporting  modern  agricultural  inputs  and 
machineries  to farms hence creating new opportunities and value addition to raw products.  
To enhance connectivity to agricultural market cent res; guidelines on effective design, construction and 
maintenance of roads linking agricultural areas with commercial cent res and/or processing plants are necessary 
to provide guidance on cost effectiveness of the roads as well as technical guidance to designers and 
contractors.  
Regardless  of the hierarc hal classification  of roads in Rwanda,  road that links districts, productive areas or other 
urban centres to national roads and other low volume roads having less than 300 vehicle per a day and 
Equivalent standard Axle road less than 1 million during the design period  either paved or unpaved ar e defined 
as “Feeder roads ”. When maintenance is not undertaken, well -built roads are bound to deteriorate and 
ultimately become impassable.  
In this standard, key aspect of maintenance, conditional assessment, typical defects and safety are addressed 
with regard to paved and unpaved feeder roads.  
In this standard, the term” should” expresses recommendations, whereas “shall” expresses requirements . 
 
 DRS  267-2: 20 21 
1                ©RSB 2021  - All rights reserved  
 Feeder roads — Part 2: Guidelines for maintenance  
1 Scope   
This Draft Rwanda S tandard gives guidelines for the maintenance  of feeder roads intended for a transport chain 
with one end in the agricultural fields and the other on the farm gate, the transport chain from the farm gate 
network to collection centre, post -harvest processing and storage facilities and a transport chain from one of 
the la tter to local markets, processing centres, post -harvest storage facility cen tres to district roads.  
This standard is applicable to classified roads. It excludes unclassified roads.  
2 Normative references   
There are no normative references in this  document . 
3 Terms and definitions   
For the purposes of this standard, the following terms  and definitions apply.  
3.1 
feeder road  
road which links districts, productive areas or other urban centres to national roads  
3.2  
productive areas  
centres for agricultural production activities, public utilities, community development centres, business c entres, 
economic zones, dumping sites, administrative offices, natural resources  processing, tourist sites  
3.3 
roadside  
areas adjoining the outer edges of the  hard shoulders  
3.4 
maintenance  
set of activities to ensure that the road remains serviceable throughout its design life and even to increase its 
life cycle . 
4 Symbols (and abbreviated terms)   
AADT   Annual Average Daily Traffic  
AASHTO  American Association of State Highway and Transportation O fficials  
ADT  Average Daily Traffic  
CBR   California Bearing Ratio  
IRI   International Roughness Index   
©RSB 2021  - All rights reserved                  2 
 LVRs  Low Volume Roads  
LVRR   Low Volume Rural Roads  
Sp   Shrinkage product  
GIS   Geographic Information System.  
5 Maintenance  
5.1 Condition assessment  
The condition for low volume roads should be assessed  using a basic public -use road management tool which 
is the Road Inventory  and Condition Assessment . It should be put in place and provide a benchmark from which 
public agencies can document the status, cond ition, funding needs and improvements of the public roads. The  
condition of the inventoried roads and the related geo -spatially based data shall be collated for use with a GIS 
and shall be available for use .  
5.2 Typical  roads defects  
In order to construct a s ound database for better decision -making in maintenance strategies and prioritization, 
typical defects on roads shall be identified and characterized. Typical defects which can affect roads are 
indicated in Table 1 . 
 DRS  267-2: 20 21 
3                ©RSB 2021  - All rights reserved  
 Table 1  — Common defects, their most common causes and their effects if left unattended  
  
©RSB 2021  - All rights reserved                  4 
 S/N Item Defects  Description  Common causes  Effects  
1 Carriageway  Loss of camber  •Camber is flat or non - existent  
•Reverse camber/edges higher 
than centre  •Poor construction  
•Poor maintenance  •Flooding & water penetration, 
softening road  
Rutting and  
potholes  •Longitudinal depression in 
road surface  •Inadequate wet strength subgrade  
•Wear by attrition  
•Excessive loose material  
•Traffic compaction of subgrade  
•Excessive axle load  •Causes poor ride quality  
•Water can collect in the rut causing 
problems  
Potholes  •Bowl -shaped depressions in 
road surface  •Water collects in the potholes  
•Excessive weakening of layer by moisture or 
traffic action  
•Inadequate initial compaction  
•Variable quality of materials  
•Insufficient structural thickness  
•Excessive axle load  •Can expand extent of damage  
•Poor rid e quality  
•Damage to vehicles  
•Can cause accidents  
Corrugations  •A series of closely -spaced 
crests and valleys in form of 
corrugation  •Inadequate quality of base materials  
•Insufficient structural thickness  •Vehicle jumps as it travels  
•Vehicles slips sideways  
•Vehicles reduce travelspeeds  
Erosion gullies  •Longitudinal depressions in 
wheel paths and road sides  •Rainwater running along the wheel path  
•Poor transversal drainage or highroad 
gradient  
•Sewage/water leaks at urban areas  •Water collects in the gullies, 
softening pavement  
•Reduced vehicle speed  
 DRS  267-2: 20 21 
5                ©RSB 2021  - All rights reserved  
  
S/N Item Defects Descript ion Common causes  Effects 
2 Shoulder  Obstruction  •Rocks, tree branches, soi ls 
etc. on the aba ndoned 
vehicles/debris •Material fall en from sl opes or blown or 
washed into road surf ace 
•Debris left by road users 
•Debris from road accidents •Hazard to road u sers 
•Obstruction of water flow from 
carriageway 
High vegetation  •Vegetative growth overru ns 
hard shoulder reaches or 
approaches roa dway e dge •Grass, wee ds, brus hes or trees allowed to 
grow ha phazardly  •Surface wat er coll ects on the 
edge of ca rriageway 
•Silt accu mulates at edge of  
carria geway  
•Visibility for road users is  reduced, 
incre asing risk of accid ent 
•Increased fire  hazard Soft spots  •Localised softening of road 
surface  •Sheer failure of base of subgrade soil  
•Traffic action combined with excessive 
moisture  
•Poor quality materials or compaction  •Road becomes impassible to traffic  
•When they extend they require 
major reconstruction  
 
Obstruction  •Rocks, tree branches, soils 
etc on the road surface  •Material fallen from slopes or blown or 
washed into road surface  
•Debris left by road users  
•Debris from road accidents  •Hazard to road users  
Loss of 
gravel/soil 
depth  •Gravel windrows along the 
road parallel to direction of 
traffic  •Loose compaction at construction or 
regravelling  
•Segregation of course aggregate from fine 
particles by traffic action  •Road is closed to traffic  
•Softening of surface makes road 
impassible   
©RSB 2021  - All rights reserved                  6 
 Scouring •Loss of ed ge su pport to 
pavement  •Lack of p ositive edge drai nage 
•Poor e dge compacti on •A safety ha zard for motorists  
•Furth er det erioration l ikely by 
exposi ng lower layers  
•Comp lete br eakup of hard 
shoulder and pavement e dge 
 Should er/carria
geway step  •Loss of ed ge su pport to 
pavement  •Lack of p ositive edge drai nage 
•Poor e dge compacti on •A safety ha zard for motorists  
•Furth er det erioration l ikely by 
exposi ng lower layers  
•Comp lete br eakup of hard 
shoulder and pavement  Rutting  •Rutting is  characterised 
by longitudi nal depressi on on 
the ro ad surface  •Carri age is t oo narr ow 
•Excessive lo ose mat erial 
•Traffic compa ction 
•Excessive axle load  
•Construction too shal low •Furth er deterioration and failure of 
shoulder 
•Standing water in the ru ts 
penetrating t he low er layer  caus ing 
early failure  
Depressions •Any deviation of surf ace from 
its or iginal sh ape •Differential  settlement of s ubgrade or base 
mater ial 
•Lack of s ubgrade sup port 
•Emba nkment  slope fail ure •Water coll ects in de pressions and 
can penetrate lower layers ca using 
softeni ng and e arly failure  
•Depression may expand into 
cracking and pothol es 
  Potholes  • Bowl -shaped depressions 
in road surface  •Water collects in potholes  
•Excessive weakening of layer by moisture 
or traffic action  
•Inadequate initial compaction  
•Variable quality of materials  
•Insufficient structural thickness  
•Excessive axle load  •Can expand extent of damage  
•Standing water can penetrate 
lower layers causing early failure  
•Failure of hard shoulder can 
lead to pavement edge failure  
S/N Item Defects  Description  Common causes  Effects  DRS  267-2: 20 21 
7                ©RSB 2021  - All rights reserved  
 3 Slopes  High 
vegetation  •Vegetative growth overruns 
slope reaches or 
approaches roadway  
edge reducing visibility and 
creating a safety  
hazard  •Insufficient grass cutting, bush clearing and 
tree trimming  •Overgrown trees or branches 
can fall blocking roadway  
•Visibility for road users is 
reduced, increasing risk of 
accident  
•Vegetation can block drainage 
system  
•Increased fire hazard  
  Erosion  •The wearing away  of 
material by natural causes 
such as water or wind  •Slope too steep  
•Poor quality materials  
•No protection on slope surface  
•Runoff water  
•Weathering ofslope  
•Poor compaction  
•Lack of cutoffdrain  •Road may be closed causing 
traffic disruption  
•Side ditch  and other concrete 
structures may be damaged  
•May cause landslide  
  Earth  
slip/slide 
Earth 
slip/slide  •Slope material sliding 
downhill because of 
instability or water 
penetration  Cut slope  
•Too steep slope gradient  
•Lack of drainage system  
•Lack of berm and berm ditch  
•Rainwater and underground waterrunoff 
between topsoil and foundation rock  
•Dip of rock orweatheredrock tends to slide  •May cause serious problem for 
third parties  
•May close road to traffic long -
term 
•Urgent countermeasures 
required  
    Embankment slope  
•Water running between natural ground and 
fill material  
•Lack of drainage system  
•Lack of berm and berm ditch  
•Lack of proper compaction  
•Lack of bearing capacity of lower layers  •May cause serious problem for 
third parties  
•May close road  to traffic long -
term 
•Urgent countermeasures 
required   
©RSB 2021  - All rights reserved                  8 
 S/N Item Defects  Description  Common causes  Effects  
 
 
3  
 
Slopes  Rock 
avalanche  •Displaced rock material 
falling by means of gravity  •Dip of rock causes rock fall  
•Poor quality control of construction  works  
•Weathering rock causes rock fall  
•Developing ofjoint rock  
•Seepage water makes rock layerslippery  •Road may be closed causing 
traffic disruption  
•Side ditch and other concrete 
structure may be damaged and 
cause drainage  
problems  
  Collapse of 
slope  •The failure of slope 
retaining structures means 
that they are unable to work 
as designed  Cut Slope  
•Poor quality materials  
•Lack of bearing capacity of structure  
•Caused by rock fall  
•Lack of proper compactionof the surface 
allowing slope to crack  
•Unstablecut slope deforms andcauses 
defects  •Cause poor countermeasure 
function for slope defects  
•Rainwater causes softening and 
weakening of slope  
•May cause erosion, rock 
avalanche and landslide  
 
    Embankment Slope  
•Unstable embankment causes slope 
protection defects  
•Poor quality fill materials  
•Poor quality of construction  
•Weathering surface slope  
•Washing out underneath ofembankment by 
river •May close road to traffic or 
create hazard and disturb the 
traffic flow  
•Side ditch and concrete 
structur es may be damaged and 
cause drainage problems  
4 Embankment  Collapse  •Movement of embankment 
to such a degree that 
structural integrity of 
materials has failed making 
it unable and unsafe to take 
any design loads  •Lack of compaction  
•Poor materials  
•Saturation due to lack of drainage or 
flooding  
•Softening of subgrade due to groundwater 
or lack of drainage  •Road shall be closed causing 
traffic disruption  
•Difficult and expensive 
reconstruction  DRS  267-2: 20 21 
9                ©RSB 2021  - All rights reserved  
 •Scouring of the toe by water action  
•Earthquake or other natural disasters  
•Excessive axle loads  
S/N Item Defects  Description  Common causes  Effects  
5 Culverts and 
bridges  Silting  •Culvert or bridge blocked 
by silt  •Invert slope too flat  
•Culvert constructed too low, so that material 
from the stream is deposited in the culvert  
•Vegetation and floating debris carried by 
the water have become lodged in the culvert  •Intended waterway opening is 
reduced  
•Water will backup or pond 
upstream or eventually overflow 
the road embankment, risking 
washing away the r oad 
  Blockage by 
debris  •Culvert or bridge blocked 
by debris  •Invert slope too flat  
•Culvert constructed too low, so that material 
from the stream is deposited in the culvert  
•Vegetation and floating debris carried by 
the water have become lodged in the culvert  •Intended waterway opening is 
reduced  
•Water will backup or pond 
upstream or eventually overflow 
the road embankment, risking 
washing away the road  
  Settlement  
cracks  •Cracks appearing on the 
surface of the road above 
the culvert  •Settlement of soil below the culvert  •If settlement minor – light 
cracking will result in headwalls, 
wing walls and mains structure  
•If major – will cause large 
relative movement of culvert 
pipes so that embankment soil 
will enter and block the culvert or 
cause culvert collapse  
  Erosion of 
stream bed at  
culvert outlet  •Stream bed of culvert outlet 
is eroded by water flow  •The culvert invert has been constructed at 
too steep a gradient so that the water flows 
too fast  
•The culvert invert has been constructed too 
flat with excessive drop at the outfall (design 
mistakes)  •The stream bed is washed away 
and a poor or ravine develops  
•The culvert downstream head 
and wing walls and even a 
section of the culvert and road 
embankment can collapse into 
the pool or ravine   
©RSB 2021  - All rights reserved                  10 
   Headwall/  
apron/wing 
wall damage  •Headwall/apron/ wing wall 
is damaged(cracked, 
collapsed)  •Minor settlement  
•Scour or erosion  
•Poor construction  
•Unexpected conditions onsite  •Erosion at the headwall/wing 
wall/apron  
•Culvert blockage or collapse  
S/N Item Defects  Description  Common causes  Effects  
5 Culverts and 
bridges  Collapse of 
culvert or 
concrete 
bridge  •Culvert or bridge collapsed 
by external forces  •Excessive load by heavy vehicles  
•Damaged by rock fall  
•Weak foundation  
•Inadequate cover to culvert  •May cause traffic accidents  
•Allows water to enter cracks and 
causes weakening of road bed  
•Runoff water causes landslide  
•Reduces drainage capacity with 
potential for flooding and causing 
damage to road foundation  
  Wearing 
down of 
wooden 
planks  •Wooden  bridge planks 
damaged by external forces  •Excessive load by heavy vehicles  
•Poor construction  
•Water running on filling material (earth and 
mud)  
•Lack of drainage system  •May cause traffic accidents  
•Allows water to enter cracks and 
causes further weakeni ng of 
bridge structure  
•May totally block road passage  
6 Ditches &  
drains  Obstruction  •Trees, branches, grass 
cuttings, silt and artificial 
waste blocks the flow of 
water  •Vegetative growth, bushes, fallen trees, 
debris, loose silt, loose rocks  
•Illegal settlements  •Blockage of ditch leading to 
flooding, erosion and potential 
erosion of ditch slopes  
  Silting  •Water flow is blocked due 
to slip up  •Invert slope is too flat, the water cannot flow 
at sufficient speed  •Blockage of the ditch causing 
flooding and potential erosion of 
the ditch slopes  
  Water 
collects in 
ditch or on 
shoulder  •Water is overflowing from 
ditch/drain  •The ditch cross section is too small  
•The ditch gradient is too flat  
•Obstruction of the ditch  •The hard shoulder material 
becomes soft and is susceptible 
to erosion  
•The pavement can also be 
flooded and thereby weakened  DRS  267-2: 20 21 
11                ©RSB 2021  - All rights reserved  
   Inverts and 
sides of 
ditches are 
eroded  •Inverts and sides of ditches 
are eroded by water flow  •Invert slope is too steep  
•Invert and slopes are not compacted  
•Material too soft and needs protection  •The erosion becomes severe 
and the sides collapse causing 
flooding and endangering the 
hard shoulder and pavement  
  Ditch lining is 
damaged  •Part of the lining has been 
broken, dislodged or 
damaged  •Poor construction workmanship  
•Soil settlement, erosion of soil under ditch 
lining  
•Poor alignment or sudden change in flow 
direction  
•Damage caused by debris  •When flowing water reaches the 
soil protected by the lining, 
erosion starts. The amount of soil 
washe d away increases, the 
lining is further damaged by loss 
of support, leading to complete 
destruction of the lining   
©RSB 2021  - All rights reserved                  12 
 S/N Item Defects  Description  Common causes  Effects  
9 Retaining wall  
/stone masonry  Settlement  •Due to i nsufficient b earing 
capacity of retaining 
wall/stone masonry is settled  •Softening of subgrade due to grou nd water, 
flood or lack of dra inage 
•Lack of c ompaction below foun dations •Risk of col lapse 
•Risk of retain ing mater ial spilling into the road  
Cracking •Crack is runn ing on  the 
surface of wall/stone masonry  •Vehicle i mpact 
•Insufficient wall  thickness 
•Excessive bu ild up of water behind  wall due 
to lack of  or block ed weep hole/drain age •Risk of col lapse 
10 Road furniture  Dirty •Road furniture (e.g. road 
sign) is d irty and/or dusty •Traffic raises  dust c louds during dry weat her 
or splashes m ud during  wet weat her •The si gn does not s erve its inten ded pur pose 
•The da nger of rusting of s teel plate s ign 
increases 
 
•Increased d anger of accidents 
Dam aged •Road furniture  (e.g. road 
sign) is d amaged •Traffic accident, vandalism  or bush fire  •The r oad users lose the b enefit of import ant 
traffic sig ns and the da nger of accid ents is 
increased 
Missing •Road furniture (e.g. road 
sign) is m issing •Weat hering, vandal ism or corrosion •The r oad users lose the b enefit of import ant 
traffic sig ns and the da nger of accid ents is 
increased DRS  267-2: 20 21 
13                ©RSB 2021  - All rights reserved  
 5.3 Maintenance management  
5.3.1 The road and bridge maintenance policy should  reflect the customer (road users)  needs.  The policy 
should  include inter alia, the following goals:  
a) support the socio -economic goals at national level;  
b) provide a minimum level of services to the road users in the country ; 
c) provide safe roads;  
d) minimise the sum of road agency and user costs;  
e) minimis e damage to the environment ; 
f) follow the guiding principles in collecting data ; 
g) collect the only required data;  
h) collect data at the lowest level of all detail sufficient to make appropriate decisions;  and 
i) collect  data only when they are needed.  
Table 2  — Data collection and frequency of road maintenance  
S/N Assessment/  
Purpose  Data Item  Frequency  
i.  Road Inventory  Road Network  
Physical Elements  Once -off exercise  
(updated when there are  
changes -verification after)  
ii.  Rideability  
(Serviceability)  Roughness  Annually  
iii.  Functional 
Evaluation  Surface Distress  Annually  
iv.  Structural  
Capacity  Mechanical  
Properties  Every 3 years  
v.  Usage (Traffic)  Traffic Volume  Annually  
Traffic Loading  Every 3 years  
5.3.2 Surface conditions and structural evaluation should  be done through roughness measurements using 
vehicle Mounted Bump Integrator and  Dynamic Cone Penetrometer  measurements, respectively.  
5.3.3 Manual classified traffic counts and axle load measurements should  be carried out regularly.  
5.3.4 The road main tenance management system  should  be based on economic analysis (Life Cycle Cost 
Benefit Analysis) aiming at minimising the sum of agency and road user costs while maintaining a certain 
minimum level of service to the road users.  
5.3.5 Traffic surveys  on feeder roads shall be carried out every 2 years and shall be conducted  in one survey 
of seven (7) consecutive days which include (5) days for 12 hours per day, and two (2) days for 24 hours each 
day at appropriate locations  .5.3.6 The road maintenance strategy shall provide an overall intervention levels 
as presented in Table 3.  
©RSB 2021  - All rights reserved                  14 
 Table 3  — Condition definition and type of intervention  
S/N Condition  Description  Intervention  
i.  Good  Allowable vehicular speed  at 40 km/hr  Routine grading and spot repairs  
ii.  Fair Allowable vehicular speed at 20 km/hr  Immediate periodic maintenance and only 
after this has been carried out shall then be 
scheduled for routine, recurrent and periodic 
maintenance.  
Emergency maintenance should be carried 
out before periodic maintenance if required  
iii.  Poor  Reconstruction and major drainage works  Reconstruction and major drainage works  
5.4 Scheduled maintenance  
5.4.1  Recurrent/routine  maintenance  
Recurrent/routine maintenance  shall be  carried out  on a regular basis once or more frequently per year on a 
section of a road, particularly before and after the rainy seasons. Tasks include:  
a) grass cutting and vegetation control ; 
b) removing small landslips  (≤ 50 m3/km);  
c) cleaning/re -shaping of side drains ; 
d) de-silting of culverts and channels ; 
e) repairing potholes ; 
f) maintenance of signs and traffic safety ; 
g) uprooting of vegetation from roadway across bridges ; and  
h) clearing of flood debris . 
5.4.2  Periodic maintenance  
5.4.2.1 Periodic maintenance should  be scheduled every  3 years (at intervals of 1 to 5 years).  Periodic 
maintenance shall involve  more comprehensive activities such as:  
a) reshaping or re -gravelling of the road surface ; 
b) repair of culverts ; and  
c) re-surfacing  and major repair or reconstruction of cross -drainage structures . 
NOTE  Periodic maintenance may require additional design.   
5.4.2.2 Specific form of periodic maintenance shall be spot maintenance, that is works should be  carried 
out on short sections (typi cally 1 km or less) of roads in order to ensure a reasonable level of passability . 
Occasionally required on a section of road after a certain period ; larger  scale  shall require  special equipment 
and skilled resources, and should need the temporary deployme nt of these resources on the particular road 
section.  DRS  267-2: 20 21 
15                ©RSB 2021  - All rights reserved  
 5.4.3  Emergency/urgent  maintenance  
Emergency shall be carried out  in response to a particular unforeseable event (e.g.  floods, land slips , etc) . The 
work required varies in accordance with the event , but shall be required immediately to re -open immediately the 
road, which would  have become impassable, to normal traffic.  The following factors affect the composition of 
the road network:  
a) topography;  
b) weather;  
c) volume of traffic;  
d) level of service standards; and  
e) age of the infrastructure.  
5.4.4  Practical aspects of maintenance  
Despite all the programming and time spent on maintenance , it is not worth doing if it is not done  cost-effectively. 
The importance of sufficient maintenance carried out by experienced and conscientious machine operators and 
back -up staff cannot be overemphasized. Once the condition of a road deteriorates beyond a certain point, 
restoration of the road  to an acceptable condition can seldom be achieved with routine maintenance and 
requires a considerable mechanical and labour input.  The following maintenance categories shall be  
considered : 
a) roadside maintenance;  
b) drainage maintenance;  and 
c) surface  maintenance.  
5.4.4.1  Roadside maintenance  
5.4.4.1.1  Bush clearing and grass cutting  shall be carried out mainly for safety reasons , but also to avoid 
damage to vehicles from vegetation overhanging the pavement edge and to reduce the fire hazard in some 
areas. The  frequency of this maintenance shall depend  on the relevant level of serviceability and should be 
adapted for the district under consideration . Areas with a high rainfall , short -radius horizontal and vertical curves 
(i.e. short sight distances) shall requi re considerably more vegetation control than long straight roads in arid 
areas  
5.4.4.1.2  Vegetation control on unpaved road reserves should be carried out manually although mechanized 
control may be cost -effective in some areas.  
5.4.4.1.3 Collection of litter should also be programmed periodically , especially near built -up areas and on 
more heavily trafficked and tourist routes. Debris from car accidents, discarded car parts (e.g. exhaust pipes 
and silencers) which periodically litter the road and dead anim als should be  removed as soon as possible.  
5.4.4.1.4 The repair and  prevention of erosion affecting cut and fill slopes and ditches  should be taken into 
consideration . The most cost effective way of preventing this erosion is the establishment of vegetation. Cuts 
and fills should be constructed at suitable batters to allow the establishment of vegetation (preferably less than 
1 vertical:  2 horizontal) with a cut -off dr ain or catch water bank just behind the crest of the cut or fill.  
5.4.4.1.5 In case of erosion , the erosion channels should be back -filled with rocks and grouted . The erosion 
of drains should also  be prevented by a rock lining and some form of obstacle (e. g. rock dams, vegetation) to  
©RSB 2021  - All rights reserved                  16 
 retard the speed of water flow. Care should be taken with vegetation as the siltation often results in vigorous 
growth and eventual filling of the drain.  
5.4.4.1.6 Erosion of culvert inlets and outlets is a common problem and c ontrol structures, e.g. rock rip -rap 
or concrete wing -walls . With time , the erosion protection measures themselves should  require significant 
maintenance.  
5.4.4.2  Drainage maintenance  
Adequate drainage maintenance should be regularly provided to overcome problems affecting roads. The 
maintenance of culverts should be carried out regularly to avoid damage to the culvert and surroundings.   
5.4.4.3  Surface maintenance  
The maintenance of the surface of unpaved roads is the major cost factor in the maintenance programme. 
Grader  blading or gravelling should be carried out depending on the status of the road deterioration.  
5.5 Safety aspects   
5.5.1 Poor safety conditions are likely to occur on unpaved roads during maintenance operations. The section 
being maintained  shall be fully signposted with the correct warning signs. The quality and condition of the signs 
should be closely controlled and the signs timely repaired where possible or replaced. The grader should be 
clearly visible over adequate distances with a hig h quality rotating warning light which shall be kept clean and 
operating.  
5.5.2 Windrows left temporarily on the road should  not be allowed to become too high and should be left for 
as short a time as possible. Under no circumstances should a  road be left partly graded overnight. An effective 
way of improving safety with respect to the presence of windrows is for the graders to work in tandem or even 
“tridem” (three in line).  
5.5.3 Caution shall be exercised to ensure that the crown is retained . 
5.5.4 Labou rers should all  be supplied with high visibility safety clothing which should be kept and worn in an 
acceptable state of cleanliness.  
 
  DRS  267-2: 20 21 
17                ©RSB 2021  - All rights reserved  
 Bibliography  
[1] RS 267 -2: 2015, Feeder roads — Part 2: Guidelines for maintenance  
[2] Technical recommendations for highways  Draft TRH 20 , The structural design, construction and 
maintenance of unpaved roads , ISBN 0 908381 87 5 , Pretoria,  South Africa, 1990  
[3] Gravel Roads - Maintenance and Design Manual  
[4] International Road maintenance Handbook -Practical guidelines for Rural road maintenance -Volume ii 
of iv- Unpaved roads  
 DRS  267-2: 20 21 
 
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©RSB 2021 - All right s reserved