Convention on Road Sings and Signals




Annex 2




Chapter II


Longitudinal markings

A. Dimensions

2. The width of continuous or broken lines used for longitudinal markings should be at least 0.10 m.

3. The distance between two adjacent longitudinal lines (double line) should be between 0.10 m and 0.18 m.

4. A broken line shall consist of strokes of equal length separated by uniform gaps. The speed of vehicles on the section of road or in the area in question should be taken into account in determining the length of the strokes and of the gaps between them.

5. Outside built-up areas a broken line should consist of strokes between 2 m and 10 m long. The length of the strokes forming the approach line referred to in paragraph 23 of this Annex should be from two to three times the length of the gaps.

6. In built-up areas, the length and spacing of the strokes should be less than they are outside built-up areas. The strokes may be reduced to 1 m. On certain main urban arteries where traffic moves fast, however, the characteristics of longitudinal markings may be the same as outside built-up areas.

B. Traffic lane markings

7. Traffic lanes shall be marked by broken lines, by continuous lines or by other appropriate means.

(i) Outside built-up areas

8. On two-way roads having two lanes, the centre line of the carriageway should be indicated by a longitudinal marking. This marking shall normally consist of a broken line. Continuous lines should only be used for this purpose in special circumstances.

9. On three-lane roads, the lanes should, as a general rule, be indicated by broken lines along sections where visibility is normal. In specific cases and in order to ensure greater traffic safety, continuous lines or broken lines adjacent to continuous lines may be used.

10. On carriageways having more than three traffic lanes, the two directions of traffic should be separated by one continuous line or by two continuous lines, except in cases where the direction of traffic in the central lanes can be reversed. In addition, the traffic lanes should be marked by broken lines (diagrams 1a and 1b).

(ii) In built-up areas

11. In built-up areas, the recommendations contained in paragraphs 8 to 10 of this Annex are applicable to two-way streets and to one-way streets with at least two traffic lanes.

12. Traffic lanes should be marked at points where the width of the roadway is reduced by kerbs, islands or directional islands.

13. At the approaches to major intersections (especially intersections where traffic is controlled), where the width is sufficient for two or more lines of vehicles, traffic lanes should be marked as shown in diagrams 2 and 3. In such cases, the lines marking the lanes may be supplemented with arrow markings (see para. 39 of this Annex).

C. Markings for particular situations

(i) Use of continuous lines

14. In order to improve traffic safety, the broken centre lines at certain intersections (diagram 4) should be replaced or supplemented by a continuous line (diagrams 5 and 6).

15. When it is necessary to prohibit the use of the part of the carriageway reserved for oncoming traffic at places where the range of vision is restricted (hill crest, bend in the road, etc.) or on sections where the carriageway is narrow or has some other peculiarity, restrictions should be imposed on sections where the range of vision is less than a certain minimum M, by means of a continuous line laid out in accordance with diagrams 7a to 16.1/ In countries where the design of motor vehicles justifies it, the eye level of 1 m indicated in diagrams 7a to 10a may be raised to 1.20 m.

16. The value to be adopted for M varies with road conditions. Diagrams 7a, 7b, 8a, 8b, 8c and 8d show, for two- and three-lane roads respectively, the design of the lines at a hill crest with a restricted range of vision. These diagrams correspond to the longitudinal section at the top of the same page and to a distance M specified in paragraph 24 below: A (or D) is the point where the range of vision becomes less than M, while C (or B) is the point where the range of vision again begins to exceed M.2/

17. Where the sections AB and CD overlap, i.e. when forward visibility in both directions becomes greater than M before the crest of the hill is reached, the lines should be arranged in the same way, but the continuous lines alongside a broken line should not overlap. This is indicated in diagrams 9, 10a and 10b.

18. Diagrams 11a and 11b show the position of the lines for the same case on a curve with restricted range of vision on a two-lane road.

19. On three-lane roads two methods are possible. These are shown in diagrams 8a, 8b, 8c and 8d (or 10a and 10b). Diagram 8a (or 8b or 10a) should be used on roads carrying a substantial proportion of two-wheeled vehicles and diagrams 8c and 8d (or 10b) where the traffic consists mainly of four-wheeled vehicles. Diagram 11c shows the arrangement of the lines for the same case on a curve with restricted range of vision on a three-lane road.

20. Diagrams 12, 13 and 14 show the lines which indicate narrowing of the carriageway.

21. In diagrams 8a, 8b, 8c, 8d, 10a and 10b, the inclination of the oblique transition lines to the centre line should not exceed 1/20.

22. In diagrams 13 and 14 which show the lines used to indicate a change in width of the available carriageway, as well as in diagrams 15, 16 and 17 which show obstacles necessitating a deviation from the continuous line(s), the inclination of the line(s) should preferably be less than 1/50 on fast roads and less than 1/20 on roads where speeds do not exceed 50 km/h (30 m.p.h.). In addition, the oblique continuous lines should be preceded, in the direction to which they apply, by a continuous line parallel to the centre line of the roadway, the length of the continuous line being the distance covered in one second at the driving speed adopted.

23. When it is not necessary to mark the traffic lanes by broken lines on a normal section of road, the continuous line should be preceded by an approach line consisting of a broken line, for a distance of at least 50 m, depending on the normal speed of the vehicles using the road. Where the traffic lanes are marked by broken lines on a normal section of road, the continuous line should also be preceded by an approach line for a distance of at least 50 m, depending on the normal speed of the vehicles using the road. The marking may be supplemented by one or more arrows showing drivers which lane they should take.

(ii) Conditions for the use of continuous lines

24. The choice of range of vision to be used in determining the sections on which a continuous line is or is not desirable, and the choice of the length of the line, is bound to be a compromise. The following table gives the recommended value of M for various approach speeds: 3/


Approach speed

Range of values of M

100 km/h (60 m.p.h.)

160 m to 320 m

80 km/h (50 m.p.h.)

130 m to 260 m

65 km/h (40 m.p.h.)

90 m to 180 m

50 km/h (30 m.p.h.)

60 m to 120 m


25. For speeds not given in the preceding table the value of M should be calculated by interpolation or extrapolation.

D. Border lines indicating the limits of the carriageway

26. The limits of the carriageway shall preferably be marked by continuous lines. Studs, buttons or reflex reflectors may be used in conjunction with these lines.

E. Marking of obstructions

27. Diagrams 15, 16 and 17 show the markings to be used near an island or any other obstruction on the carriageway.

F. Guidelines for turning vehicles

28. At certain intersections it is desirable to show drivers how to turn left, in countries with right-hand traffic, or how to turn right in countries with left-hand traffic.

G. Road markings for a lane reserved for certain categories of vehicle

28-bis. The marking of lanes reserved for certain categories of vehicle shall be by means of lines which should be clearly distinguished from other continuous or broken lines of the carriageway, notably by being wider and with less space between strokes. With respect to a lane reserved primarily for buses, the word "BUS" or the letter "A" shall be marked on the reserved lane wherever necessary and specifically at the beginning of the lane and after intersections. Diagrams 28a and 28b show examples of markings for a lane reserved for regular public transport service vehicles.



1/ The definition of range of vision used in this paragraph is the distance at which an object 1 metre (3 ft. 4 in.) above the surface of the carriageway can be seen by an observer on the road whose eye is also 1 metre (3 ft. 4 in.) above the carriageway.

2/ The marking between A and D shown in diagrams 7a and 7b may be replaced by a single continuous centre line, without a broken line alongside, preceded by a broken centre line consisting of at least three strokes. Nevertheless, this simplified arrangement should be used with caution and only in exceptional cases, since it prevents the driver from overtaking for a certain distance even though the range of vision is adequate. It is desirable to avoid using both methods on the same route or on the same type of route in the same area, as this may lead to confusion.

3/ The approach speed used in this calculation is the speed which 85 per cent of the vehicles do not exceed, or the design speed if it is higher.


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