ICS 93.080.30  
 
Reference number  
DRS 312: 2023 
© RSB 2023 
  
 RWANDA 
STANDARD  DRS  
312  
 
Second  edition  
2023-mm-dd 
 
Road traffic safety  — Traffic control 
device s — Requirements  
   
DRS  312: 20 23 
©RSB 2023 - 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 2023 
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  312: 2023 
iii                ©RSB 2023 - All rights reserved  
 Contents  Page 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 General principles of road traffic control devices  ................................ ................................ .... 3 
5 Classification and use of road traffic control devices  ................................ ..............................  4 
5.1 Classification  ................................ ................................ ................................ ................................  4 
5.2 Use of road traffic control devices  ................................ ................................ .............................  4 
5.3 Road traffic signs  ................................ ................................ ................................ .........................  4 
6 Signing system  ................................ ................................ ................................ .............................  4 
7 Design and use of signs and road markings  ................................ ................................ .............  4 
7.1 7.1 General  ................................ ................................ ................................ ................................ .... 4 
7.2 Legibility  ................................ ................................ ................................ ................................ ........  4 
7.3 Regulatory signs  ................................ ................................ ................................ ..........................  5 
7.4 Warning signs  ................................ ................................ ................................ ...............................  7 
7.5 Information signs  ................................ ................................ ................................ .........................  8 
7.6 Supplementary signs  ................................ ................................ ................................ ...................  9 
7.7 Traffic light signals  ................................ ................................ ................................ .....................  10 
7.8 Road markings  ................................ ................................ ................................ ............................  12 
7.9 Signs at road works  ................................ ................................ ................................ ...................  14 
8 Positioning of road signs and road markings  ................................ ................................ .........  16 
8.1 Road signs  ................................ ................................ ................................ ................................ .. 16 
8.2 Siting  ................................ ................................ ................................ ................................ ............  17 
8.3 Position relative to the edge of the carriageway  ................................ ................................ ..... 18 
9 Manufacture of road signs and road markings  ................................ ................................ ....... 19 
9.1 Sign lettering  ................................ ................................ ................................ ...............................  19 
9.2 Construction  ................................ ................................ ................................ ...............................  21 
9.3 Reflectorisation  ................................ ................................ ................................ ..........................  21 
9.4 Frames supports and fittings  ................................ ................................ ................................ .... 22 
9.5 Back support frame  ................................ ................................ ................................ ....................  23 
9.6 Sign plate preparation and coatings  ................................ ................................ ........................  23 
9.7 Installation of signs  ................................ ................................ ................................ ....................  24 
9.8 Road markings  ................................ ................................ ................................ ............................  25 
9.9 Reflective road studs  ................................ ................................ ................................ .................  26 
9.10  Maintenance of signs and road mark ings................................ ................................ ................  27 
 DRS  312: 20 23 
©RSB 2023 - 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 S tandards adopted 
by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 312 was prepared by Technical Committee RSB/TC 9, Civil engineering and building materials . 
In the preparation of this standard, refer ence was made to the following documents : 
1) SANS 1519 -1:2006, Road signs  - Part 1: Retro -reflective sheeting material  
2)  SANS 1519 -2:2006, Road signs - Part 2: Performance requirements for road signs  
3) Traffic signs manual  - Nepal 
The assistance de rived from the above source is hereby acknowledged with thanks.  
This second edition cancels and replaces the first edition (RS 312: 2016 ), [clauses …. ] which has been 
technically revised . 
Committee membership  
The following organizations were represented on the Technical Committee on Roads and highway engineering  
(RSB/TC 55) in the preparation of this standard.  
ASTRIK International Ltd  
EDITRACE LTD  and General Reliance  
JV CSC&EC  (Property) and Fair Construction Ltd 
MININFRA  
NPD Ltd  
Rwanda Inspectorate Competition and Consumer Protection Athority (RICA ) 
Rwanda Transport Development Agency (RTDA)  
TCMF Ltd  DRS  312: 2023 
v                ©RSB 2023 - All rights reserved  
 University of Rwanda - College of Science Technology (UR -CST)  
Rwanda Standards Board (RSB) – Secretariat  
 DRS  312: 20 23 
©RSB 2023 - All rights reserved                  vi 
 Introduction   
Clear and efficient signing is an essential part of the road network for the enforcement of traffic regulations and 
for road safety, and a road with poor signing or with badly maintained signs is an unsatisfactory road.  
This standard provides details of the traffic control devices which are used on roads in Rwanda, including their 
layout and symbols, the circumstances in which each sign may be used and rules for siting and positioning 
them.  
The standard also provides guidance on the te mporary traffic measures required at roadworks.  
 
   DRS 312: 20 23 
1                ©RSB 2023 - All rights reserved  
 Road traffic safety — Traffic control devices — Requirements  
1 Scope  
This Draft Rwanda Standard specifies requirements for road traffic safety signs, signals and markings for use 
on new and existing roads.  
This standard also specifies requirements for temporary road traffic safety signs for use on road works.   
This standard applies to all classes of roads.  
2 Normative references   
The following documents are referred to in the text in such a way that some or all of  their content constitutes 
requirements of this document.  For dated references, only the edition  cited applies. For undated references, the 
latest edition of the referenced document (including any amendments) applies.  
ASTM D 4956 -16a, Standard Specificati on for Retroreflective Sheeting for Traffic Control  
RS EAS 293 -1, Road marking materials — Part 1: Physical properties  
RS ISO 4998, Continuous hot -dip zinc -coated carbon steel sheet of structural quality  
3 Terms and definitions   
For the purposes of this stan dard, the follow ing terms and definitions apply . 
3.1  
traffic control devices  
all signs, signals, markings, and other devices used to regulate, warn, or guide traffic, placed on, over, or 
adjacent to a street, a road, pedestrian facility,  parking facility  or bikeway by a competent authority  
3.2  
road  
the entire surface of any way or street open to public traffic  
3.3 
carriageway  
part of a road normally used by vehicular traffic; a road may comprise several carriageways clearly separated 
from one another by , for example, a dividing strip or a difference of level exit of the definition   
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 3.4 
lane  
part of a road which has been marked out for use by one moving line of vehicles  
3.5 
bicycle la -ne 
part of a carriageway designated for cycles. A bicycle lane is distinguished from the rest of the carriageway by 
longitudinal road markings  
3.6 
intersection  
any level crossroad, junction or fork, including the open areas formed by such crossroads, junctio ns or forks  
3.7 
level -crossing  
any level intersection between a road and a railway or tramway track with its own track formation driver any 
person who drives a motor vehicle or other vehicles (including a cycle)  
3.9 
pedestrian crossing  
part of a road whi ch is painted  with white stripes, also known as a “zebra crossing”  
3.10 
road user  
anyone  using the road or  travelling, or present on a road, or in a vehicle on a road  
3.11 
traffic  
moving vehicles  or pedestrian  
3.12 
traffic island  
a raised area or marke d over which vehicles may not pass,  or placed at a street junction, or between opposing 
traffic lanes    DRS 312: 20 23 
3                ©RSB 2023 - All rights reserved  
 3.13 
vehicle  
any machine propelled along the road by any power, pedal cycles, hand carts, or animal drawn  carts  
4 General principles of road traffic contro l devices  
4.1 Signs shall give road users their message clearly and at the correct time. The message shall be 
unambiguous and speedily understood. Using standard signs assists in their quick recognition, as does 
uniformity of shape, colour and lettering for each type. To obtain the fullest benefits of uniformity, there shall not 
only be uniformity of signs, but also uniformity in their use, installation and  illumination.  
4.2 Signs are provided to control and guide traffic and to promote road safety. They should only be used where 
they can usefully serve these functions.  
Signs are only effective if:  
a) they are visible,  
b) they are legible,  
c) they are understandable,  
d) the road users k now what they mean, and  
e) the road user is motivated to behave correctly.  
Items a) and b) depend on the correct installation or fixing and maintenance of signs; item c) depends on the 
design of the signs and symbols being as self-explanatory  as possible; ite ms d) and e) depend on the 
implementation of education and enforcement.  
4.3 It is important that the message be presented in a simple way. A picture or symbol can be much more 
effective than words, and can be understood by those who cannot read. Use worded  signs only where there is 
no alternative.  
4.4 Signs should be sited where the background will not distract the eye from the sign.  
4.5 The symbols and legends on signs shall be easy to read. This means that the symbols and lettering need 
to be large enough  to enable drivers to read it at the required distance.  
4.6 Traffic signs shall be clearly visible at night. It is not sufficient to rely on illumination by vehicle headlights, 
and signs shall be reflectorised either wholly or in part.  
4.7 Traffic signs sh ould be constructed and erected so that they will last for the design life of the intended 
roadwithout any attention apart from occasional cleaning.   
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 5 Classification and use of road traffic control devices  
5.1 Classification  
Road traffic control devices are clas sified according to their functions (see 5.3).  
5.2 Use of road traffic control devices  
Road traffic control devices shall be used by all road users in compliance with laws and regulations on road 
traffic applicable in Rwanda.  
5.3 Road traffic signs  
Traffic signs (including road markings) shall be divided into three broad types:  
a) Regulator signs which give instructions, prohibitions or restrictions which road users shall obey;  
b) Warning signs which warn of hazards on the road ahead; and  
c) Information signs which give d irections and distances to destinations or which provide other information 
that may be relevant to road users.  
6 Signing system  
There are three basic types of traffic sign: signs that give orders, signs that warn and signs that give information. 
Each type ha s a different shape. A further guide to the function of a sign is its colour. All circular signs give 
orders, most of all triangular signs warn, all rectangular signs inform.  
Another important group of signs are road markings. These can regulate, warn and inform, and some help clarify 
or emphasise the message given by other signs.  
7 Design and use of signs and road markings  
7.1 7.1 General  
In order to simplify the design of the regulatory and warning road signs defined in this standard, the size of the 
signs  shall be specified in terms of the designation of the road on which they shall be erected. Where additional 
impact is required, it may be necessary, in certain circumstances, to specify a larger sign than the road 
designation requires. This can generally be done where a sign is erected on or at the end of a section of road 
where vehicle speeds have not been constrained by road surface condition or geometry. It may also be 
necessary to increase the size of a sign where experience has shown that drivers igno ring a sign, has led to 
accidents.  
7.2 Legibility  
7.2.1  The size of the information signs and supplementary plates shall be governed by the lettering height of 
the lettering used on the sign.    DRS 312: 20 23 
5                ©RSB 2023 - All rights reserved  
 The sizes of information signs containing text shall be determined b y the size of text required. This is defined in 
terms of the height of an upper case “A” or lower case “x” and is referred to as the “A - height” and the “x -height”  
respectively (See figure 3).  
7.2.2  A sign shall be capable of transmitting its message clear ly and at the right time to road users travelling at 
the normal speed for the road during day and night. To achieve this, a sign shall have correct legibility distance, 
appropriate target value, simple content and layout, and effective reflectorisation  by the use of appropriate 
reflective sheet made from either micro prisms, or encapsulated lenses  and glass beads for road painting . Signs 
shall also be adequate in design and construction.  
7.2.3  The legibility of signs shall be determined by the size of the s ymbol or lettering used. Contributory factors 
include the use of adequate colour contrast between the symbols or lettering and the background and the type 
of any alphabet used.  
The factors which determine the distance over which a sign message is legible s hall include:  
a) size of symbol or text;  
b) number of messages to be scanned;  
c) lateral distance of the sign from the edge of carriageway; and  
d) The speed of the approaching vehicle  
7.3 Regulatory signs  
7.3.1  Use 
7.3.1.1  Regulatory signs shall put into practical effect th e road traffic regulation or control of traffic.  
Regulatory signs are either mandatory/obligatory or prohibitory.  
7.3.1.2  The mandatory signs shall give instructions to drivers about what they shall do.  
7.3.1.3  Mandatory signs shall be circular in shape wi th a white symbol and border on a blue background.  
7.3.1.4  The prohibitory signs shall give instructions to drivers about what they shall not do. Prohibitory signs 
shall be circular in shape with a red border.  
7.3.1.5  Regulatory signs shall only be used wh ere it is considered essential that traffic be controlled for safety 
reasons or for efficient use of the road system.  
7.3.1.6  Portable STOP signs shall not be used except for emergency and temporary traffic control zone 
purposes.   
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 7.3.2  Sizes and siting  
7.3.2.1  The size of the regulatory signs shall depend upon the designation of the road on which 
they were erected. The size of sign shall be as shown on Table 1  
Table 1 – Sizes of regulatory signs  
 
 
 
 
 
 
 
 
 
7.3.2.2  Signs giving effect to traffic regulation orders, and intended to be read from a moving vehicle, shall be 
of sufficient size to enable drivers to recognise them and assimilate the information in time. They shall therefore 
need to be of a size appropriate to the prevailing traffic speed on the  road on which they are used.  
7.3.2.3  Exception to the standard sizes shall be on Stop signs, Go signs and Give Way signs which shall be 
750 mm except within urban areas where there may be a case for a 600 mm sign.  
7.3.2.4 Regulatory signs shall be sited at or near the point where the instruction applies. It is important to make 
sure that there is no confusion about which road they refer to. Drivers shall be able to see the sign from at least 
60 m away (75 m on National  roads) so that they have time to read the message and act on it.  
Regulatory signs shall be placed at the right - hand side of the road, but a second sign on the left -hand side may 
be used where extra impact is needed.  
7.3.3  Traffic speed restriction signs  
Speed  limits should be both reasonable  and enforceable. Departures from the National speed limit should only 
be imposed where the situation is such that it is definitely unsafe for vehicles to maintain the higher speed.  
This should only be used in urban areas w ith considerable pedestrian traffic and for traffic crossing a bailey  Road designation  Diameter of Sign (mm)  
National roads, Districts and City of Kigali roads and that of other 
urban areas - Class One  600  
Location on national roads, Districts and City of  
Kigali roads and that of other urban areas - Class One  750  
  
Town and urban roads  600  
Town and urban roads where space is limited  450  
Signs attached to traffic signal columns  300  
NOTE The definition of “where additional impact is required” is to be found in 7.1.    DRS 312: 20 23 
7                ©RSB 2023 - All rights reserved  
 bridge. Traffic calming measures such as road humps should be incorporated t o introduce an element of “self -
enforcement”.  
Note Drawings of each of the regulatory signs are shown in the relevant laws and regulations applicable in Rwanda.   
7.4 Warning signs  
7.4.1  Warning signs shall be used to alert drivers to danger or potential danger ahead. They shall indicate a 
need for extra caution by road users and may require a reduction in speed or other manoeuvre.  
7.4.2  Adequate warning signs can greatly assist road saf ety. To be most effective however, they should be used 
sparingly. Their frequent use to warn of conditions which are otherwise readily apparent tends to detract from 
their effectiveness.  
7.4.3  Warning signs shall not be used in situations where the problem  is obvious, or is so minor that no extra 
care is necessary. Side road junctions for example are not usually a danger when traffic speeds are low.  
7.4.4  Warning signs shall be triangular in shape with a red border encompassing a black symbol on a white 
background. The black symbol shall normally be a diagram of the hazard.  
7.4.5  Additional information should be put onto a supplementary plate below the main sign. There shall always 
be a distance clear of obstructions in advance of the sign. The sign should n ot be sited just after an obstruction 
or a sharp bend. Drivers shall be able to see the sign from at least 60 metres away and75 metres on National  
roads so that they have time to read the message. Warning signs shall be placed at the right -hand side of the  
road.  
7.4.6  It takes time for a driver to act on the message given by a sign and slow his/her vehicle down to a safe 
speed. Therefore,  signs shall be sited sufficiently far ahead of the hazard to allow for this. Signs shall also be 
large enough to be read  clearly by drivers travelling at above average speeds. In general,  the sizes and 
distances are determined by the design speed, however in order to simplify the specification of warning signs, 
Table 2 stipulates the size and distances in terms of road desi gnation. If it is necessary to site the sign away 
from the standard position, the distance to the hazard should be indicated on the supplementary plate  
 
Table 2 – Sizes and siting of warning signs   
Road Designation  Size of sign   
(Height of triangle in mm)  Distance of Signs from 
hazard   
(m)  
National roads  750  180  
Locations on national roads where additional impact is 
required  900  180  
District roads   750  100  
Town and urban roads  600  50   
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 Locations of signs in town and on urban roads where 
additional impact is required.  750  50  
Note  The definition of “where additional impact is required” is to be found in 7.1.   
Note Drawings of each of the warning signs are shown in the relevant laws and regulations applicable in Rwanda  
7.5 Information signs  
7.5.1  Direction signs  
7.5.1.1  These signs shall give drivers information to enable them to find their way to their destination.  
7.5.1.2  Good direction signing should help to reduce delay and frustration; to keep traffic flowing smoothly and 
safely through junctions; and to promote com merce and tourism.  
Direction signs belong to the following groups:  
a) advance direction signs which give a driver information about his route ahead before he reaches a road 
junction;  
b) direction signs which give route information at a junction; and  
c) route confi rmatory signs which give confirmation and often additional information about the route ahead 
after a road junction.  
7.5.1.3  Direction signs used on national roads shall have a capital letter height of 150 mm. Direction signs used 
on other roads including feeder roads shall have a text height of 100 mm.  
The text height for route confirmation signs shall be 100 mm for capital l etters irrespective of the road 
designation.  
7.5.2  Other information signs  
These information signs may serve one of the following purposes:  
a) they may give advance information of prohibitions or restrictions ahead or they may indicate the end of a  
restriction or prohibition;  
b) they may give civic or geographical information such as the name of a town or village; and  
c) they may give information abo ut facilities ahead such as parking places, lay -bys, picnic areas,  hotel, police 
station, hospital, touristic destination  etc.   DRS 312: 20 23 
9                ©RSB 2023 - All rights reserved  
 7.5.3  Overhead signs  
7.5.3.1  An overhead sign may be required:  
a) where the message is applicable to a particular lane (or lanes), over wh ich the sign is placed;  
b) on a roadway of two or more lanes in one direction where heavy traffic may interfere with the visibility of a 
roadside sign;  
c) where roadside development with brightly lit commercial signs seriously detract from the effectiveness of a  
roadside sign;  
d) where vertical or horizontal curvature limits the visibility of a roadside sign;  
e) for consistency, where other signs on a section of a road are overhead;  
f) on an overhead structure, to indicate a low clearance;  
g) to identify a cross street or a turn control at a signalized intersection;  and 
h) where it is deemed necessary to place a warning sign assembly with a large backboard and/or flashing light 
overhead for emphasis.  
7.5.3.2  Overhead mounted signs shall provide a vertical clearance of not less t han 4.8 m to the sign, light fixture, 
or sign bridge, over the entire width of the pavement and shoulders except where a lesser vertical clearance is 
used for the design of other structures.  
7.5.3.3  Overhead sign should be illuminated for emphasis at night . 
7.5.4  Information signs lettering  
For direction signs, the upper and lower case lettering shall be used. The direction signs, with the exception of 
temporary diversion signs, shall use either white lettering and symbols on a dark green background or black 
lettering and symbols on a white background. Temporary diversion signs will use black lettering and symbols 
on a yellow background. The background on the signs which are dark green should not be reflectorised, but the 
letters and symbols should be. Other direc tion signs should not be reflectorised.  
Note Drawings of each of the information signs are shown in the relevant laws and regulations applicable in Rwanda.  
7.6 Supplementary signs  
Supplementary plates shall give additional information or clarify the message given by the main signs. They are 
mostly used with regulatory or warning signs. They shall not be used on their own. The supplementary plates 
shall be mounted 75 mm below the primary sign. The text shall have a capital letter height of 60 mm. Note 
Drawings of each of the supplementary signs are shown in the relevant laws and regulations applicable in 
Rwanda.   
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 7.7 Traffic light signals  
7.7.1  This group of signs comprises of two categories:  
a) signs for the control of vehicles; and  
b) signs for the contro l of pedestrian crossing movements.  
7.7.2  The signal head should be mounted so that its lower edge is about 2.3 m above carriageway level. The 
signal should be close to the kerb or edge  of the carriageway, but sufficient clearance shall be left to prevent 
the signal head being struck by vehicles. The signal lenses should have hoods to prevent them being seen by 
drivers on other approaches.  
7.7.3  Where appropriate, a 300 mm diameter version of a regulatory sign (such as “no right turn”) may be 
displayed at t he side of the signal head, preferably level with the green light.  
7.7.4  The traffic signals ahead warning sign may be needed on the approaches to the junction.   
7.7.1  Signs for the control of vehicles  
7.7.1.1  The primary purpose of a traffic signal installation  at a road junction shall be to reduce conflict between 
traffic streams. Conflict at a junction is manifested as an increase in delay and an increase in the accident rate. 
The installation should be designed to achieve safety and efficiency within the conf ines of the available road 
space.  
7.7.1.2  Traffic control shall be done by means of red, amber and green light signals, supplemented by additional 
green, amber and red arrow light signals and regulatory signs as necessary.  
7.7.1.3  Traffic light signals sha ll be placed on the nearside of each approach and shall be known as primary 
signals. Additional primary signals may be required on one -way streets. The stop line  and STO P letter  shall be 
marked on the carriageway 1.3 m in advance of the signal. The signal and stop line may be set back to 
accommodate a pedestrian crossing, or to make turning movements easier for long vehicles.  
7.7.1.4  Each road which meets at the junction shall be described as an arm of that junction and each arm shall 
be considered as havin g one or more approaches depending on the intended direction of travel of the traffic 
stream on leaving the signalled area.  
7.7.1.5  Additional displays may be included beyond the junction and shall be known as secondary signals.  
7.7.1.6  The main purpose of  the secondary signal shall be to indicate  to vehicles close to the stop line, the same 
information as the primary signal. In certain circumstances the secondary signal may not be positioned beyond 
the junction on a particular approach. On these occasions the secondary may be on the entry side of the 
junction, preferably on the offside and beyond the stop line.  
7.7.1.7  Each traffic stream shall have clear vision of the primary signal on its approach and the additional 
displays which are associated with it. The sequence signalling shall be red, green, amber and red.  
7.7.1.8  The instruction conveyed by each coloured light signal is defined as follows:    DRS 312: 20 23 
11                ©RSB 2023 - All rights reserved  
 a) Red light - Denotes that traffic is prohibited from proceeding beyond the stop line.  
b) Green light - Indicates t hat vehicular traffic may proceed beyond the stop line, and may turn in any direction, 
subject to the normal priority rules being observed and provided that the turn is not prohibited by a 
supplementary light signal (red arrow) or a regulatory traffic sign . 
c) Amber light - Conveys same prohibition as red signal except where vehicles are  so close to the stop line 
that they cannot  safely stop before stop line, they should proceed. This phase is usually displayed for three 
seconds.  
7.7.1.9  Additional green arrows may be fitted as follows:  
a) on the left of the three light display indicating a movement to the left. The arrow light may also be l it when 
the main signal is red to indicate that vehicles may turn left only.  
b)  on the right of the three light display, indicating a movement to the right.  
7.7.1.10  When green arrows are used, drivers have come to expect an exclusive right of way. Therefore, there 
should be no conflict with traffic already using the junction.  
7.7.1.11  An additional amber left arrow may be fitted on the left of the three light display  indicating a movement 
to the left even when ahead may be shown as a red signal. The amber left arrow indicates that it is permissible 
to go left provided that vehicles give way to traffic using the junction. This type of arrow should not be used in 
conjun ction with a pedestrian crossing.  
7.7.1.12  An additional red light arrow may be fitted on the right of the three light display indicating that a turn to 
the right is prohibited when the arrow light is lit.  
7.7.1.13  Wherever green or amber narrow lights are  used, the arrow light shall flash for 3 seconds before it is 
turned off. Red arrow lights shall not flash before being turned off.  
7.7.2  Signals to control pedestrian movements  
7.7.2.1  Pedestrian signals shall only be used in conjunction with traffic lights. Si gnal-controlled pedestrian 
crossings are appropriate at sites where traffic speeds are high or where pedestrian  flow is very heavy.  
Crossings with pedestrian signals can also be incorporated in junctions controlled by traffic lights.  
7.7.2.2  The light sig nals to be displayed on a pedestrian signal are red, green and flashing green. Phasing of 
Pedestrian signal with traffic signal is detailed in Table 3. The instructions conveyed by each coloured pedestrian 
signal are:  
a) Red standing man - Denotes that pedest rians are prohibited from crossing the road.  
b) Green walking man - Denotes that pedestrians may cross the road with care.  
c) Flashing green man - Denotes that pedestrians are prohibited from crossing the road except where they 
have started to cross the road, in  which case they should continue to cross the road.   
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 Table 3 – Phasing of Pedestrian signal with traffic signal  
SNo  Pedestrian Signal  Vehicle Signal  Period  
1  Red standing man  Green  Dependent upon cycle time  
2  Red standing man  Amber  3 seconds  
3  Red standing man  Red  Minimum to clear traffic in the junction  
4  Green walking man  Red  6-12 seconds depending upon carriageway width 
and pedestrian density( see note below)  
5  Flashing green man  Red  See note below  
6  Red standing man  Red  1-3 seconds, but see note below  
Note Timings for green man may not apply for signal controlled junctions. The time of periods 5 and 6 together (in seconds) 
are equal to the width of the carriageway in meters divided by 1.2. When the green man pedestrian signal is lit, it may be 
justified  to use a simultaneous audible signal.  
7.7.2.3  The signal head is normally sited on the same post as the traffic light. The signals controlling pedestrian 
movements shall face across the road so that the signal can be clearly seen by pedestrians. This si gnal lenses 
shall be hooded to prevent the signal being seen by drivers.  
7.8 Road markings  
7.8.1  Classification of markings  
7.8.1.1  Road markings are classified as follows:  
a) transverse lines which are laid across the road at right angles to the flow of traffic:  
1) Stop lines; and  
2) Give way lines  
b) Markings at pedestrian crossings;  
c) Longitudinal lines which are laid along the road parallel to the flow of traffic:  
1) Lane lines;  
2) Barrier lines;  
3) Traffic island markings; and    DRS 312: 20 23 
13                ©RSB 2023 - All rights reserved  
 4) Edge of carriageway  
d) marking for parking res trictions; and  
e) traffic lane arrows  
7.8.1.2  The purpose of road markings shall be to control, warn, or guide road users. They may be used to 
supplement other traffic signs or they may be used alone. Their major advantage is that they can give a 
continuing m essage to the driver. Thus they can be used to guide drivers in the correct positioning of their 
vehicles so that the traffic flows smoothly and safely.  
7.8.1.3  Road markings should be considered in detail at the design stage of new or improved junctions. The 
markings for existing junctions are often best considered on plan before the work is undertaken.  
Note Drawings of each of the road markings are shown in the  relevant laws and regulations applicable in Rwanda.  
7.8.2  Reflectorisation  
7.8.2.1  At night it becomes much more difficult to see and understand the road and junctions ahead. Road 
markings can be of great help, especially if they are reflectorised. This is achi eved by the addition of glass beads 
known as ballotini which is either incorporated in the paint mix or applied after the marking is laid.  
The improved efficiency of reflectorised lines is substantially reduced when the lines are wet, although  
reflectoriz ed lines including paints, cold applied plastics, thermoplastic, self -adhesive tapes, modified epoxy 
resins and rais ed pavement markers using special glass beads (retroreflective beads ) are still at least as good 
as unreflectorised lines. Because of their advantage over unreflectorised lines in dry weather much more use 
of reflectorised lines is justified.  
The following road markings should be reflectorised to improve the visibility:  
a) transverse stop lines;  
b) continuous white lines (barrier lines);  
c) all markings at major junctions; and  
d) centre and edge of carriageway lines on sections of main road with many curves or gradients.  
7.8.2.2  White coloured reflective road studs should be considered for continuous white lines along the centre 
line of the road an d around traffic island markings. Red coloured reflective road studs should be considered for 
outlining physical traffic islands. There may also be situations where white coloured reflective road studs are 
proposed to improve longitudinal markings for lane  line and hazard warning line markings.  
7.8.3  Road centre line marking  
A continuous road center line marking shall be provided to prohibiting overtaking on lengths of road where 
visibility is limited. The system shall use a single 1 20 mm wide line which is cont inuous where overtaking is  
©RSB 2023 - All rights reserved                  14 
 prohibited. Where additional impact is required, the width of the line should be increased to 150 mm. Where 
overtaking is not prohibited, but it may be dangerous to overtake, a hazard warning line shall be provided.  
Details of e ach of the types of road markings are shown RS EAS 293 -1. 
7.9 Signs at road works  
7.9.1  General  
7.9.1.1  When any work is carried out on or close to a road or street adequate measures shall be taken to warn 
and protect both road users and road workers.  
7.9.1.2  Good s igning on road works should warn, inform and direct road users. It should warn road users that 
there is a hazard ahead, so that they can be ready to take action. It should inform them of what kind of thing to 
expect, so that they know what manoeuvre or act ion to be made and it should direct them how to pass through 
the hazard in a safe manner. Good signing should also help protect the workers on the road and keep traffic 
delays to a minimum.  
The road works site Engineer shall:  
a) plan ahead - It is his/her res ponsibility to sign the works safely and think what signs and cones needed 
before leaving the site;  
b) provide high visibility - All persons working on or near the road shall wear brightly -coloured clothing, 
preferably an orange or yellow waistcoat/jacket;  
c) face the traffic when setting out signs - The Road Works Ahead warning sign shall be put out first and then 
moved towards the works site, and always the site Engineer should face the traffic when setting out the 
signs and cones;  
d) fix the signs properly - The s igns shall be secured so that they cannot be blown over or dislodged by moving 
traffic. Signs that are mounted on a metal or wood frame which keeps the sign face off the ground should 
be used. A sand bag or rock placed across the base of the frame should b e used to stop the sign being 
blown over. The signs should be checked regularly to see if they are all still in place;  
e) ensure the signs are visible at night - The road works site Engineer should make every effort to finish the 
work before dark, but, if thi s is not possible, reflective signs and cones shall be used, and preferably they 
should be supplemented with flashing lights;  
f) remove unnecessary signs - The road works site Engineer shall never leave signs on the road once they 
are no longer needed;  
g) keep t he site tidy - The road works site Engineer should take up as little road space as possible, and store 
construction materials and equipment off the road;  
h) always use the standard signs - The road works site Engineer or his/her representative shall not desig n his 
own. All signs shall be authorized by the competent authority before using them.    DRS 312: 20 23 
15                ©RSB 2023 - All rights reserved  
 7.9.2  Basic sign needed  
7.9.2.1 The Road Works Ahead sign - shall be the first sign to be seen by the driver. It shall be placed well 
before the work site about 30 m in town a nd 60 m on rural roads, but on a high -speed national road, it should 
be 200 m away. Put the sign where it can be seen from a distance. For example, if the works are just after a 
bend in the road, put the sign before the bend. This sign has a black symbol o n a white background, all within 
a red triangle.  
7.9.2.2  The Road narrows ahead sign – shall warn drivers which side of the road is obstructed. It should only 
be used on high -speed national roads.  
This sign should be placed midway between the Road Works Ah ead sign and the works site. This sign has a 
black symbol on a white background, all within a red triangle.  
7.9.2.3  Keep left or, if appropriate, Keep  right – These signs shall be placed at the beginning and end of the 
works at the point where the works extend furthest into the road. These signs have a white arrow on a light blue 
background.  
7.9.2.4  A line of traffic cones – Shall be used to guide pedes trian and vehicle traffic past the works. Some 
working space shall be left between the line of cones and the actual excavation or works area. Traffic cones 
should be red, and, if used at night, should preferably have white reflective sleeves.  
7.9.2.5  STOP / GO signs - Where there is a lot of traffic or the works site is very long, the traffic shall be 
controlled manually using these STOP / GO boards operated by a responsible adult. If the obstruction is less 
than 30 m long and is on a straight section of ro ad, a single board operating at one end or in the middle shall 
be used. Flags should used by an experienced adult for not confusing road users.  
Sign plates for use on high -speed roads should be 750 mm high. On low -speed (50km/h or less) roads, 600 
mm high signs should be used.  
The basic traffic signs for road works are illustrated in the Figure 1  
  
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Figure 1 — Illustration of basic  road work  signs  
8 Positioning of road signs and road markings  
8.1 Road signs  
Three things shall be considered when positioning a tra ffic sign:  
  DRS 312: 20 23 
17                ©RSB 2023 - All rights reserved  
 a) its siting in relation to the junction, hazard, etc., to which it refers;  
b) Its position in relation to the edge of the carriageway; and  
c) the height of the sign plate and its angle to the road.  
The following should be checked before sign positionin g: 
a) the signs are clearly visible;  
b) there is no confusion about which road they refer to;  
c) the signs do not obstruct the view of drivers;  and 
d) the signs are not placed where they could be struck by vehicles.  
8.2 Siting  
8.2.1  Drivers shall be given the message at t he right time, neither too late for the driver to take action, nor too 
soon that the driver has forgotten it by the time he has to act on it.  
8.2.2  Regulatory signs shall be sited at or near the point where the instruction applies.  
8.2.3  Each sign shall be designed to be read from a certain distance, which is determined by the road 
designation. The sign shall be sited where it can be seen from this distance.  
8.2.4  Signs should generally be sited on the right -hand side of the road. Howeve r, at sharp right - hand bends, 
it may be better to put the sign on the left -hand side of the road where it can be more noticeable.  
8.2.5  Most warning signs, and some direction signs, shall be sited in advance of the hazard or junction to which 
they relate.  The distance depends on the road designation. When signs need to be sited far away from their 
standard position, a supplementary plate may be used to give the distance to the junction or hazard. The 
distance between a sign and the junction or hazard to wh ich it relates should be increased, rather than being 
decreased.   
©RSB 2023 - All rights reserved                  18 
 8.3 Position relative to the edge of the carriageway  
8.3.1  Signs should be placed so that no part of the sign is closer than 600 mm from the outer edge of the 
shoulder, or carriageway in the case  of roads without shoulders (see Figure 1).  
  
Figure 2 — Mounting height  
 
8.3.2  This also applies to signs positioned on traffic islands. This is to reduce the risk of them being hit by 
passing vehicles. The siting of signs at places where vehicles stop o r park on the shoulder should be avoided.  
8.3.3  Height and angle of the sign plate Signs should be mounted so that the lower edge of the sign plate is 2 
000 mm above the level of the carriageway (see Figure 1). This helps to discourage vandals and bill pos ters 
from defacing the sign plate.  
8.3.4  Signs should never be mounted less than 2000 mm above ground level.   
8.3.5  Where two warning signs are to be mounted on the same post, the sign that relates to the nearest hazard 
should be at the top.  
8.3.6  Temporary road signs should be mounted on a frame which keeps the sign above ground by at least 300 
mm. 
8.3.7  Signs erected over footways and in urban areas shall be high enough to enable pedestrians to walk 
beneath them. The lower edge of the sign place should be about 2.0 metres above the surface of the footway.  
  DRS 312: 20 23 
19                ©RSB 2023 - All rights reserved  
 8.3.8  Sign plates shall be mounted so that they face the driver. On unlit roads, the plate should be angled slightly 
away from the road to avoid mirror reflection when illuminated by vehicle head lights (see Figure 2).  
 
 
Figure 3 — Angle of sign plate  
9 Manufacture of road signs and road markings  
9.1 Sign lettering  
9.1.1  The size of the lettering shall be referred to in terms of the capital letter height. This shall be the height of 
the uppercase letter . 
9.1.2  To ensure correct lettering spacing when forming a word, the characters in each alphabet should be placed 
on tiles. The tiles shall vary in width, according to the size of the character, and shall have a fixed height which 
ensures correct line spac ing. For the purpose of design, the line spaces shall be measured to the edge of the 
tiles and not to the actual characters. The tile height is given on Figure 3 below.  
9.1.3  Details of the lettering are shown in Table 4. Each letter has been put onto a t ile which is related to the 
height and width of each letter of the alphabet.  
 
©RSB 2023 - All rights reserved                  20 
  
Figure 4 — Lettering tile  
 
Table 4 – Capital and tile heights for lettering   
Sign type  Capital height   
(mm)  Tile height  
(mm)  
Place identification signs  200  285  
Direction signs on national roads  150  215  
Bridge name plate sign (Name of bridge)  150  215  
Direction signs on feeder roads and other minor roads  100  145  
Supplementary plates  60  85  
The standard lettering style is given in Table 5.  
The widths of letters and numerals are given in terms of their capital height h.  
 
  DRS 312: 20 23 
21                ©RSB 2023 - All rights reserved  
  
9.2 Construction  
The materials used in the signs and the method of construction shall comply with ASTM D 4956. Retroreflective 
sheeting use d for the construction of sign plates is a type of material which is capable of reflecting light in the 
general direction of the light source. For simplicity this shall be referred to hereafter as reflective sheeting.  
9.3 Reflectorisation  
9.3.1  Signs should be  fully reflectorised except for those parts of the sign which are coloured black. If a sign is 
required to have a reflectorised background, the sign face shall be made of reflective sheeting.  
 
©RSB 2023 - All rights reserved                  22 
 9.3.2  Signs which are intended to be positioned parallel to the direction of traffic flow such as parking sign shall 
not be reflectorised.  
The reflective sheeting shall conform to the following requirements:  
a) the sheeting shall have high reflectivity normal to vehicle headlights dependent on the angle of incidence. 
The reflective material shall be sharp and glareless and directed towards the light source at an approved 
angle of incidence;  
b) the surface of the sheeting shall be smooth and flexible. No cracking shall occur when bent. Reflective 
sheeting shall have high durability under all weather conditions, heat and moisture and be strongly fungus -
resistant.  
c) the sheeting shall not delaminate, blister, crack, peel and chip during the manufacturing process and during 
its expected service life;  
d) the sheeting supplied shall  be free from dirt, solid lumps, scales, ragged edges and non -uniformity of colour;  
e) the colour of the sheeting shall be even and free from any spots or loss of colour. The colour shall not fade 
appreciably under local weather conditions during its expecte d service life;  
f) colours of sheeting used shall correspond to the colours of the sheeting supplied as samples;  
g) the reflective surface of the sheeting shall be durable and remain sharp during its expected service life. Bad 
weather conditions such as rain, de w, etc. shall not considerably reduce the reflectivity;  
h) the reflective surface of the sheeting shall be easily cleaned with soap and water with no adverse effect on 
its reflectivity and durability when used on the roads;  and 
i) the adhesive used on the backin g of the sheeting shall give a high quality bonding to clean, smooth and 
grease free aluminium or other sign plates approved by the sheeting manufacturer. The adhesive shall 
withstand the conditions without allowing the sheeting to peel.  
9.4 Frames supports an d fittings  
9.4.1  Steel frames shall be free from scale and rust by blast cleaning or pickling and protected by one of the 
following methods:  
a) thermally spraying with aluminium or zinc to a nominal thickness of 100 mm;  
b) hot dip galvanising in accordance with RS ISO 4998 followed by a coat of suitable pre -treatment primer 
where a finishing coat is to be applied;  
c) applying two coats of inhibitive primer followed by one of undercoat;  
d) applying a plastics coating.    DRS 312: 20 23 
23                ©RSB 2023 - All rights reserved  
 9.4.2  When the frame is of welded construction, the weld areas shall be freed of scale and treated to give a 
protection equivalent to that given to the remainder of the frame. The frame shall be fabricated prior to the 
application of any finishing coat.  
9.4.3  Steel fittings and accessories such as clips, br ackets, screws, bolts, nuts, rivets and washers shall be 
prepared and finished as above.  
9.4.4  The reverse of signs should have a top coat finish colour of either grey or black. All post shall be painted 
in alternate black and white stripes at 200 mm to 25 0 mm band widths.  
9.5 Back support frame  
Unless otherwise specified, aluminium sign plates, and steel sign plates greater than 0.4 m2 in areas, shall be 
supplied with a back support frame of a size and design to avoid the plate being deformed due to wind press ure, 
or manipulation by vandals (other than severe attack). The frame shall normally be made of a steel angle riveted 
or bolted to the sign plate, and shall incorporate brackets to enable the sign plate to be bolted to the sign post.  
All screws, bolts, nut s, washers, rivets, etc., shall be protected against corrosion. Steel fixings that come into 
contract with aluminium must be coated with zinc or cadmium to prevent corrosion through electrolytic action.  
The complete sign when mounted on its support in acco rdance with the manufacturer’s instructions shall be 
rigidly locked in position to resist twisting.  
9.6 Sign plate preparation and coatings  
The choice of aluminium or steel shall be governed by the type of sign being manufactured. The sign plates for 
all fully  reflective signs should be aluminium.  
Non-reflective or partially reflective signs shall use steel sign plates. Wood or reinforced concrete shall not be 
acceptable as materials for sign plates.  
9.6.1  Aluminium  
If aluminium is chosen, the aluminium sheeting shall be 2 mm thick unless otherwise specified. After any cutting 
and punching has been completed all sharp edges shall be uniformly rounded off and smoothed down.  
The metal plate shall be degreased either by  acid or hot alkaline etching and all scale/dust removed to obtain a 
smooth, plain surface.  
After cleaning, metal shall not be handled except by a device or clean canvas gloves.  
There shall be no opportunity for metal to come into contact with grease, oil,  or other contaminants prior to the 
application of the reflective sheeting.   
©RSB 2023 - All rights reserved                  24 
 9.6.2  Steel  
9.6.2.1  If steel plate is chosen, the steel plate shall be 1.25 mm thick. However, plate thicknesses of 1.6 mm 
which is more generally available, or 2.0 mm are  acceptable.  Also the steel plate is provided depending on the 
type of roads.  After any cutting, welding and punching has  
been completed, all sharp edges shall be uniformly round off and smoothed down.  
9.6.2.2  All physically adhering contaminants shall be removed and th e surfaces abrasive -blasted and then 
thoroughly cleaned and degreased. Unless the application of a primer follows within 4 hours of the abrasive 
blasting and before any oxidation of the prepared surfaces takes place, the surface shall be given one coat of 
wash primer immediately after blasting.  
9.6.2.3  The prepared surface shall be given two coats of a zinc chromate primer. The first coat is to be applied 
within 12 hours in the case of wash -primed surfaces and within 4 hours, but before any oxidation of the  surface 
takes place, in the case of abrasive -blasted surfaces that have not been wash -primed.  
9.6.2.4  There shall be no opportunity for the metal to come into contract with grease, oil or other contaminants 
prior to the application of the reflective sheet ing. 
9.6.3  Coating  
Parts of the sign plate not covered by reflective sheeting (including the reverse of the plate and the back support 
frame) shall be coated using either by painting, stove enameling or powder coating processes. The colour of 
the reverse of sign  plates and support frame shall be grey or black.  
9.7 Installation of signs  
9.7.1  Mounting posts  
Mounting posts should be installed in accordance with the accepted practice of manufacture. The steel tube, to 
be used should have at least 50 mm internal diameter, howe ver 78 mm by 38 mm C - channel should be equally 
acceptable and has the added advantage of giving a flat surface on which to bolt the sign plate. Posts 
constructed from wood or reinforced concrete will not be acceptable.  
Before using other types of steel se ction for posts, the competent authority shall need to be consulted that the 
proposed post shall not suffer any permanent deformation or other form of failure when it is subjected to the 
estimated working stresses.  
9.7.1.1  Fixing  
9.7.3.1.1  The method of fixing the  sign plate (and frame if used) to the mounting post(s) should be such as it 
shall facilitate its removal for replacement purposes. A typical method of fixing unframed signs to a circular post 
is by the use of half clips which are riveted, bolted or welded  to the sign plate. A typical method for fixing a larger 
framed sign is for the back support frame to have two flanges one at the top and one at the bottom.  
The sign is then fixed to the sign post by bolting through the flanges.    DRS 312: 20 23 
25                ©RSB 2023 - All rights reserved  
 9.7.3.1.2  Each type of sig n plate and mounting post presents its own fixing problem, but the aim should be to 
provide a fixing for the sign plate (and frame if used) so that although it can be easily removed for replacement 
purposes, it is held firmly enough to withstand the loadin g to which it will be subjected. All nuts, bolts, washers 
etc, shall be protected against corrosion. Steel fixings that come into contact with aluminium shall be coated 
with zinc or cadmium to prevent corrosion through electrolytic action.  
9.7.3.1.3  In ord er to help prevent theft of the sign, the ends of the threads of fixing bolts should be filled  
down, deformed with a hammer or the thread spot welded.  
9.7.3.1.4  Where a sign is mounted on a single post, care should be taken to prevent the forced rotation of the 
sign round it. In the case of a circular post, this may be achieved by means of a pointed grub screw in the clip 
which is screwed into the post.  
9.7.3.1.5  Care should be taken to prevent the rotation of the post in its foundation. This may be achieved by 
passing a length(s) of bar through holes drilled in the base of the post below ground level. For additional rigidity, 
the bar can be welded to the base of the post.  
9.7.1.2  Foundations  
9.7.3.2.1  The type of foundations required, particularly for larger direction signs, shall vary with the local soil 
conditions. These may be in mass concrete or reinforced concrete. The buried section should be at least one -
third the overall length of the post. Unless otherwise specified the foundation for a single post should be at least 
450 mm x 450 mm and 600 mm deep. The concrete should be a 1:3:6 cement: sand: gravel mixture.  
After pouring, it should be properly compacted with a tamper. The top surface should be smooth with a slight 
slope outwards from the post to ensure proper drainage. The top surface of the finished concrete should not be 
proud of the surrounding ground surface as the provision of foundation bl ocks or plinths can enable vandals to 
reach the sign plate more easily.  
9.7.3.2.2  The foundation should be designed and placed at such a depth that it shall safely support the sign 
under its loading conditions without causing failure due to shear or heave in the surrounding soil. Special 
precautions should be taken to ensure the adequacy of foundations in made up ground. Foundation for the large 
directions signs should not be covered up until they have been inspected and approved by the Engineer.  
9.7.3.2.3  Temporary struts should be used to hold the post in position until the foundation is complete, making 
sure that the post is vertical and that the sign plate is level and at the correct angle to the road. The installation 
date should be painted on the back of the sign.  
9.8 Road markings  
9.8.1  The paint used for road markings should be manufactured specifically for this purpose and should comply 
with RS EAS 293 -1. It should be quick -drying, durable, and have a good skid -resistance.  
9.8.2  The paint may be applied by brush or machine, however before ordering paint, the proposed method of 
application should be specified to the manufacturer to ensure that the correct type of paint is ordered. Hot 
sprayed plastic or thermoplastic may also be used.   
©RSB 2023 - All rights reserved                  26 
 9.8.3  Markings shall not be laid until the correct temporary traffic signs are in place. The road surface shall be 
clean and dry, and completely free from dirt, grease or any other material that might prevent the paint from 
adhering properly. The outline of the marking should be marked on the road surface with chalk or paint spots.  
It is worth making templates for the more complicated markings such as arrows. The paint may be applied 
bybrush or by machine. Traffic shall not be allowed over the markings until they are dry. On c ompletion the 
longitudinal lines should present a smooth visual flow to be the eye with no kinks or sudden bends.  
9.8.4  Carriageway markings may be laid either by hand or by machine. The choice shall depend on such factors 
as the type of material, the patt ern of the marking, how frequently the pattern is repeated, and on the amount 
to be laid. In busy urban areas, consideration shall be given to clearing the street of parked vehicles; the only 
alternative may be to operate at night, or at weekends.  
9.8.5  All types of carriageway markings should be skid -resistant in wet conditions. Adequate skid resistance is 
particularly important where the camber or crossfall is steep and at junctions where turning traffic includes an 
appreciable number of two -wheeled vehic les. 
9.8.6  As it is not possible to lay carriageway markings to precise dimensions and in order to allow for the 
markings “spreading” in service, certain tolerances in the prescribed dimensions may be permitted.  
These are:  
a) 3 m or over Plus or minus 15%;  
b) 300 mm or over, but under 3 m Plus or minus 20%; and  
c) Under 300 mm Plus 30% or minus 20%  
9.8.7  The maximum projection of the line marking above the surface should be 6 mm. This should not be 
exceeded because of the danger to traffic, especially to two -wheeled  vehicles, and to pedestrians. Where 
markings are relaid over existing markings after surface dressing of the carriageway, care should be taken to 
ensure the overall projection of the markings should also not exceed 6 mm.  
9.9 Reflective road studs  
The followin g points should be considered when specifying studs:  
a) glass lenses are much more resistant to wear than plastic;  
b) corner cube reflectors have a greater reflective performance than bi -convex lenses but tend to be more 
expensive; and  
c) strong fixing is vital for  safety - road nails plus epoxy glue is advisable for asphalt, however using anchored 
road studs on surface dressed road is not advised as it is likely to result in a weakness in the impermeable 
surfacing which could lead to local failure.    DRS 312: 20 23 
27                ©RSB 2023 - All rights reserved  
 9.9.1  Installation of bonded road studs  
9.9.1.1  Bonded road studs should be fixed in accordance with the manufacturer’s instructions.  
9.9.1.2  The road surface should be cleaned and dust, oil, grease and other contaminants removed. The surface 
should, where possible, be allowed to weather and compact for a minimum period of 6 weeks to 8 weeks 
depending on traffic conditions prior to the installation of permanent studs.  
9.9.1.3  Road studs should not be installed on white lines or on joints in the road surface. They should be installed 
when the road surface is completely dry unless the manufacturer of the adhesive recommends that it is suitable 
for use in other conditions.  
9.9.1. 4 A blowlamp may be used to prepare the road surface in damp or cold weather, but care should be taken 
not to overheat the road surface as this can weaken it.  
9.9.1.5  In cases of doubt, the adhesive manufacturer’s advice should be obtained on whether the a dhesive is 
appropriate to the surface in question.  
9.9.2  Method of use of adhesive  
9.9.2.1  Any settling of fillers or pigments in the adhesive components should be completely dispersed by stirring 
before the components are mixed.  
9.9.2.2 Just before use, the com ponents should be thoroughly mixed to give a homogeneous mixture of uniform 
colour. The manufacturer’s instructions should be followed regarding the application of the adhesive and any 
safety precautions. The adhesive should be used as quickly as possible after mixing and never after it has 
started to set in the container.  
9.9.2.3  The whole of the bottom surface of the road stud should be allowed to set sufficiently before allowing 
traffic to over run the stud.  
9.9.3  Installation of anchored road studs  
Anchored r oad studs should be fixed in accordance with the manufacturer’s instructions.  
The cavities formed in bituminous surfaces should be thoroughly cleaned. In cold weather, the temperature of 
the bituminous material immediately surrounding the cavities formed t o accept the anchored part of an anchored 
road stud, may be gently heated in order to prevent rapid cooling of any heated bituminous adhesive or grout 
used in the cavity.  
Care is taken not to overheat the road surface as this can weaken it.  
9.10 Maintenance of signs and road markings  
9.10.1  General  
9.10.1.1  Traffic signs, traffic lights and carriageway markings, including reflecting studs, shall be maintained to 
fulfil their purpose.   
©RSB 2023 - All rights reserved                  28 
 9.10.1.2  All signs and markings including reflecting road studs, should be inspected at regular and frequent 
intervals both by day, and when appropriate, for reflectance at night. They should be renewed as necessary. 
Signs become less effective not only when characters or colouring deteriorate, but also when dirty or damaged 
or displaced a s a result of accidents. Damaged or dirty signs lessen road users’ respect for the signs. A periodic 
inspection of signs should be made to ensure their early repair and/or replacement when necessary, and after 
dark inspections should be made of reflectoris ed signs.  
9.10.1.3  Regular cleaning of all signs shall be done.  
9.10.1.4  To ensure proper maintenance, a suitable schedule should be established for the inspection. Cleaning 
of signs should occur at least twice a year and signs should be replaced immediate ly when damaged or missing. 
One inspection per year should be carried out at night to ensure adequate brilliance of reflectorized surfaces.  
9.10.1.5  Care should be taken that vegetation does not obstruct the sight line of a traffic sign. Deep snow may 
require the seasonal raising of sign heights.  
9.10.1.6 For illuminated signs, a regular schedule of lamp replacement should be maintained so that lamps are 
renewed before they are normally expected to burn out.  
9.10.1.7  Markings should be renewed or relaid af ter resurfacing or on the completion of road works which may 
have interfered with them.  
9.10.1.8  Arrangements should be made to protect road studs during surface dressing operations.  
9.10.1.9  Road law enforcement, maintenance staff and other public agencie s whose duties require that they 
travel on the roadways should immediately report a damaged, deteriorated or obscured and missing sign at the 
first opportunity.  
9.10.2  Maintenance regime  
9.10.2.1  Proper record -keeping and regular inspection should be the key to g ood maintenance. An inventory of 
markings, signs, and other road furniture should be helpful. In addition to a description of the item and its 
location, it can usefully include installation and inspection dates, and repair details. The inventory number sho uld 
be painted on the back of the sign plate.  
9.10.2.2  Inspections should be made at least twice a year, preferably after routine cleaning has been done. The 
things to look for are:  
a) signs that are missing or in the wrong location;  
b) signs that are pointing the wrong way or are tilting;  
c) signs that are hidden by trees or bushes;  
d) posts that are loose in their foundations;  
e) sign plates that are loose;    DRS 312: 20 23 
29                ©RSB 2023 - All rights reserved  
 f) corrosion of sign plates and posts;  
g) accident or other damage;  
h) flaking or faded sign faces and painted su rfaces;  
i) poorly reflecting sign faces (best checked at night);and  
j) worn or faded road markings.  
9.10.2.3  The faults that are found and the action taken shall be recorded.  
9.10.3  Cleaning  
Signs should be cleaned at least twice a year, and priority should be given to  low-mounted signs. Any long 
grass, bushes or tree branches which hide the sign face shall be cut back. Water and a mild detergent to wash 
the sign should be used and care note to scratch the surface shall be taken.  
The sign in clean water to remove all tr aces of detergent shall be rinsed. Road tar can be cleaned off with petrol 
or white spirit, but the cleaner shall be careful not to dissolve the paint.  
9.10.4  Repairs  
Minor repairs and repainting can be done on -site. Repainting should only be done in dry weather and after  
proper preparation of the surface. Paint shall not be applied to reflective sheeting, because this makes it 
nonreflective. Similarly, ordinary road paint shall not be used on reflectorised road markings.  
9.10.5  Storage and transport of signs  
Signs shal l always be stored where they cannot be damaged. They shall be stacked vertically, if possible, and 
sheets of cardboard or thick paper shall be put between them to prevent the sign faces from getting scratched.  
Care shall be taken when loading signs on an d off trucks, and they shall not be allowed to bounce around while 
being transported.  
9.10.6  Assessment of effectiveness of signs and road markings  
As part of the maintenance programme, the location and frequency of accidents should be recorded. From these 
record s, it can be established where accidents on the road network most frequently occur. Accident sites should 
be looked at in more detail to establish whether better signing or road marking would improve safety and reduce 
accidents.   
©RSB 2023 - All rights reserved                  30 
 Bibliography  
[1] Presidential d ecree no 85/01 of 02/09/2002 regulating general traffic police and road traffic  
[2] LAW N°55/2011 OF14/12/2011 Governing Roads in Rwanda  
[3] Convention on road signs and signals of 1968  (Vienna convention)  
[4] Manual Uniform Traffic Control Devices for Streets and Highways  
[5] Southern African Development Community  - General Principles  
[6] Southern African Development Community  - Regulatory Signs  
[7] Southern African Development Community  - Warning Signs  
[8]        Southern African Development Community  - Information Signs  DRS 312: 2023 
 
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©RSB 2023 - All rights  reserved