Road Markings (Part - 1) - Civil Engineering (CE) PDF Download

Classification

The road markings are defined as lines, patterns, words or other devices, except signs, set into applied or attached to the carriageway or kerbs or to objects within or adjacent to the carriageway, for controlling, warning, guiding and informing the users. The road markings are classified as longitudinal markings, transverse markings, object markings, word messages, marking for parking, marking at hazardous locations etc.

 Longitudinal markings 

Longitudinal markings are placed along the direction of traffic on the roadway surface, for the purpose of indicating to the driver, his proper position on the roadway. Some of the guiding principles in longitudinal markings are also discussed below.

Longitudinal markings are provided for separating traffic flow in the same direction and the predominant color used is white. Yellow color is used to separate the traffic flow in opposite direction and also to separate the pavement edges. The lines can be either broken, solid or

double solid. Broken lines are permissive in character and allows crossing with discretion, if traffic situation permits. Solid lines are restrictive in character and does not allow crossing except for entry or exit from a side road or premises or to avoid a stationary obstruction. Double solid lines indicate severity in restrictions and should not be crossed except in case of emergency. There can also be a combination of solid and broken lines. In such a case, a solid line may be crossed with discretion, if the broken line of the combination is nearer to the direction of travel. Vehicles from the opposite directions are not permitted to cross the line. Different types of longitudinal markings are center line, traffic lanes, no passing zone, warning lines, border or edge lines, bus lane markings, cycle lane markings.

Center line Center line 

separates the opposing streams of traffic and facilitates their movements. Usually no center line is provided for roads having width less than 5 m and for roads having more than four lanes. The center line may be marked with either single broken line, single solid line, double broken line, or double solid line depending upon the road and traffic requirements. On urban roads with less than four lanes, the center line may be single broken line segments of 3 m long and 150 mm wide. The broken lines are placed with 4.5 m gaps (figure 29:1). On curves and near intersections, gap shall be reduced to 3 meters. On undivided urban roads with at least two traffic lanes in each direction, the center line marking may be a single solid line of 150 mm wide as in figure 29:2, or double solid line of 100 mm wide separated by a space of 100 mm as shown in figure 29:3. The center barrier line marking for four lane road is shown in figure 29:4.

 Traffic lane lines 

The subdivision of wide carriageway into separate lanes on either side of the carriage way helps the driver to go straight and also curbs the meandering tendency of the driver. At intersections, these traffic lane lines will eliminate confusion and facilitates turning movements. Thus traffic lane markings help in increasing the capacity of the road in addition ensuring more safety. The

traffic lane lines are normally single broken lines of 100 mm width. Some examples are shown in figure 29:5 and figure

 No passing zones 

No passing zones are established on summit curves, horizontal curves, and on two lane and three lane highways where overtaking maneuvers are prohibited because of low sight distance. It may be marked by a solid yellow line along the center or a double yellow line. In the case of a double yellow line, the left hand element may be a solid barrier line, the right hand may be a either a broken line or a solid line . These solid lines are also called barrier lines. When a solid line is to the right of the broken line, the passing restriction shall apply only to the opposing traffic. Some typical examples are shown in figure 29:7 and figure 29:8. In the latter case, the no passing zone is staggered for each direction.

 Warning lines 

Warning lines warn the drivers about the obstruction approaches. They are marked on horizontal and vertical curves where the visibility is greater than prohibitory criteria specified for no overtaking zones. They are broken lines with 6 m length and 3 m gap. A minimum of seven line segments should be provided. A typical example is shown in figure 29:9