The factors include highway factors, highway traffic operation factors, maintenance aspects, road user amenities, road side plantation and general amenities.

The planting of trees along road side is called as arboriculture, in few cities like Visakhapatnam, Andhra Pradesh a green belt is maintained and garden is also provided but planting of trees is called arboriculture.

Illegal encroachment and ribbon development are most common particularly in rural areas, it?s very difficult in encroached areas for development.

The minimum desirable distance from edge of pavement is 2.5m and 12m from centre of pavement.

As farmers have only agricultural land for ir living, compensation should be paid well before construction of highway project.

The right of way for a national highway should be wide enough and it should be available for furr expansion, flat slopes with camber and smooth alignment and trees for plantation are best alignment.

The cross drainage structure is considered in highway factors which includes geometry and drainage works, highway traffic and road users are also benefitted by drainage system.

In urban areas most of trees can?t provide shade due to place restriction, but most of m provide beauty, shade can?t be expected till 20 years and fruits are not edible in a polluted zone.

The EIA denotes environmental impact assessment, in which road side development is assessed based on impact by using environment studies and environmental assessment.

The minimum number of trees required in new avenue of a nursery for one kilometre length are 270 in new avenue and 150 in old, 100 and 150 in new and old sites respectively.