To stop soil erosion. Because where trees are planted the rain dont directly fall on the soil. The rainwater fall on the upper part of the tree and than it goes down and than it seeps down through the soil and recharge the ground water. If trees are not present the rain will hit the soil directly and flood the whole area

Environmental Benefits
- Air Quality Improvement: Trees act as natural air filters by absorbing pollutants and releasing oxygen, contributing to cleaner air.
- Temperature Regulation: They provide shade, helping to reduce the urban heat island effect and lowering temperatures in surrounding areas.
- Biodiversity Support: Roadside trees create habitats for various species, promoting biodiversity in urban settings.
Safety Enhancements
- Traffic Calming: Trees can influence driver behavior, encouraging slower speeds and enhancing road safety.
- Visibility and Aesthetics: Strategically placed trees can improve visibility for drivers while also enhancing the visual appeal of the roadway.
Social and Psychological Benefits
- Community Well-being: Green spaces, including tree-lined roads, contribute positively to mental health by providing a serene environment.
- Recreational Spaces: Trees can facilitate outdoor activities and encourage community engagement, making areas more inviting for pedestrians and cyclists.
Economic Advantages
- Increased Property Values: Proximity to green spaces often leads to higher property values, benefiting local economies.
- Tourism Attraction: Scenic tree-lined roads can attract tourists, boosting local businesses and enhancing the area’s economic prospects.
Maintenance and Sustainability
- Soil Conservation: Tree roots help prevent soil erosion, maintaining the integrity of roadways and surrounding landscapes.
- Water Management: Trees assist in managing stormwater runoff, reducing flooding risks and improving water quality.
In summary, planting trees along roads provides numerous environmental, safety, social, economic, and maintenance benefits, making them a vital component of urban planning and community development.