1. Evaluation and design of road lighting

2. Need
To enable road users to see the carriageway and immediate surroundings in darkness
Causes of road accidents
Headlight driving insufficient, glare problem, accidents
Hence, the need to illuminate the carriageway

3. Mounting height High mounting reduces glare Uniform luminance Costlier
Mountings of 7.5 – 12 m for traffic routes and 3 – 8 m for other streets
More powerful the lamp, increased mounting height, to reduce the glare

4. Spacing
Not to exceed 55 m
Preferably 35 – 45 m on important traffic routes
Spacing should be between 3 and 5 times the mounting height

5. Lantern arrangements
Single sided
Staggered
Central
Opposite

6. Quantity of illumination needed on different streets
Recommended average illumination (lumens/sq. m)

7. Average illumination of streets in lumens / sq. m
= ((lamp lumens) * (coefficient of utilization) * (lantern maintenance factor)) / ((spacing between lanterns in m) * (width of roadway in m))

8. Lamp installation at T junctions and cross roads
Lantern is located in the major road, just beyond the entrance from the side road, to indicate the driver on the side road that he is approaching a T junction

9. Cross - roads

10. Traffic Rotaries Lantern A – above the curb of central island
Lantern B – above each section of the outer curb of the rotary
Lantern C – provided when pedestrians cross the channelising island