Manual of Planting and Landscaping of Urban Roads

IRC SP 119-2018: Paradigm Change in Landscaping of Roads

This manual introduces sustainable landscaping integrated with urban roads to mitigate air pollution, heat islands, urban flooding, water scarcity, and erosion.

Key Highlights:

• Air Pollution & Heat Island Mitigation: Use wide-canopy shade trees and permeable pavements.
• Urban Flooding: Incorporate bio-swales, detention systems, and natural drainage swales to manage stormwater.
• Water Scarcity: Promote drip irrigation, recycled water, and xeriscaping.
• Tree Protection: Maintain clear height of 4.5 m above carriageway; protect root zones.
• Planting Strategy (Traffic Islands, Medians, Plazas):
  • Avoid dense low-branching trees; prefer high-branched, well-pruned trees.
  • Flowering shrubs up to 1.5 m for aesthetics.
  • Use permeable paving and integrate infiltration systems.
  • Provide seating around tree pits without obstructing stormwater flow.

Typical Specifications:

Design Process Flow (Fig. 1 Summary):

flowchart TD
    A[Planning & Survey] --> B[Design Methodology]
    B --> C[Implementation Details]
    C --> D[Maintenance & Monitoring]

References in IRC SP 119:

• Chapter 1: Paradigm Change (p.5)
• Chapter 2: Design Methodology (p.11-58)
• Chapter 3: Implementation Details (p.70-122)

Use this manual as a framework for sustainable, functional, and aesthetic urban road landscaping.

IRC SP 119-2018: Design Methodology with Landscape and Planting

Key Points from Chapter 2 (Pages 11-70):

• Survey Requirements (2.1):
  Conduct detailed topographic and vegetation surveys to record existing trees, soil conditions, and microclimate.

• Design Approach (2.2 & 2.3):

  • Tailor planting based on project type (Greenfield, retrofit, public improvements).
  • Follow road hierarchy for plant selection and landscape layout (expressways, arterial, sub-arterial, local roads).
  • Consider functional zones: central median, verge, footpath, and buffer strips.

• Planting Strategy (2.5):

  • Use native, drought-resistant species to reduce irrigation needs.
  • Planting density and spacing depend on species growth habits and road width.
  • Incorporate bio-swales and stormwater management (2.6) for runoff control.

• Functional Design (2.7):

  • Ensure visibility and safety; avoid obstructing sightlines.
  • Integrate street furniture and utilities with planting.

Specifications & Tables (Chapter 3 Highlights):

Example: Planting Spacing Guideline (Indicative)

IRC SP 119: Implementation Details – Key Points

1. Functional Design (Clause 2.7)

• Focus on integrating landscaping with road functionality.
• Includes storm water management, erosion control, and tree protection.
• Refer to Clause 2.7.10 for Water Treating Plants (see Table 12).

2. Standards and Specifications (Chapter 3)

• 3.1 Standards (p.70): General guidelines for materials, workmanship.
• 3.2 to 3.5: Detailed specs for plantation types and tree protection.
• 3.6 Typical Details for Street Furniture (p.97): Dimensions, materials.
• 3.7 Storm Water Management (p.101): Decentralized systems, runoff control.
• 3.8 Irrigation Specifications (p.114): Includes drip irrigation, recycled water use.
• 3.9 Integration with Utilities and Sub-grade Protection (p.122).

Table 12: Water Treating Plants (Clause 2.7.10)

• Lists types, capacities, and treatment methods.
• Ensures sustainable water use in landscaping.

Example: Irrigation Design Parameters (from 3.8)

flowchart LR
    A[Road Landscaping] --> B[Functional Design (2.7)]
    B --> C[Water Treating Plants (Table 12)]
    B --> D[Storm Water Management (3.7)]
    B --> E[Irrigation (3.8)]
    B --> F[Tree Protection (3.5)]

Summary: Use Chapter 3 for detailed specs; Clause 2.7 for design integration; Table 12 for water treatment.

IRC SP 119 - Maintenance: Key Formulas, Tables & Specifications

1. Maintenance Schedule (Table 19: Arboriculture Regime)

• Year-wise activities focus on:
  • Surveying & cleaning
  • Digging pits & procurement of materials
  • Plantation & watering frequency (4-6 times/month depending on season)
  • Weeding, hoeing, and casualty replacement (20% in 3rd year, 10% in 4th year)
  • Maintenance by Mali (gardener) throughout years 2 to 4

2. Transplantation of Large Trees (Clause 3.11.1 & Table 18)

• Key Aspects:
  • Age & size: Younger & smaller girth trees transplant better
  • Timing: Dormant season (July-Aug best)
  • Health: No major defects/disease
  • Site: Should match original conditions
  • Aftercare: Multi-year watering & monitoring essential
• Success rate influenced by: species, root ball size, health, equipment, expertise

3. Monitoring Parameters (Table 20)

Summary Diagram: Maintenance Timeline

gantt
    dateFormat  YYYY-MM
    title Maintenance Activities Over 4 Years
    section Year 1
    Survey & Cleaning           :done, 2024-01, 3M
    Pit Digging & Procurement  :done, 2024-01, 3M
    section Year 2
    Plantation & Watering       :active, 2024-04, 11M
    Weeding &

Design Approach Based on Road Hierarchy (IRC SP 119 - Clause 2.3)

Additional Specifications:

• Clear Sight Distance (Clause 4.5 & Table 8):

• Tree Pruning Heights:
  • Minimum 4.5 m clearance over carriageway
  • Minimum 2.4 m clearance over pedestrian/cycle paths

Slope & Drainage (Clause 2.7.14):

• Balance cut and fill on stable slopes; cut only on unstable.
• Use grass swales and bio-swales to manage runoff.
• Stabilize slopes with native vegetation or retaining walls for steep slopes.

flowchart TD
    A[Road Hierarchy] --> B[Local Streets]
    A --> C[Collector Roads]
    B --> D[Shade Trees, Traffic Calming, Drainage]
    C --> E[Screening, Shade, Safety, Drainage]
    D --> F[Plant: High Branching, Deep Roots, Low Water]
    E --> F

This summary integrates key design and planting guidelines for road hierarchy from IRC SP 119, ensuring functional, safe, and sustainable urban road landscaping.

Planting Strategy for Various Road Components (IRC:SP:119-2018)

Key Guidelines & Specifications

• Tree Lines: Plant trees in straight lines aligned with movement direction.
• Climate Adaptation: Use shade-giving trees in hot climates.
• Native Species: Prefer native plants for longevity and low maintenance.
• Visibility & Safety: Maintain clear walking zones (2.4 m height clearance) by pruning.
• Avoid Monocultures: Mix species to reduce disease risk.
• High Branching Trees: Use trees with canopy spread of 6-8 m or more and clear height of 4.5 m above road level.

Planting by Location

Key Specifications & Formulas from IRC SP 119 for Special Planting & Water Scarcity

1. Irrigation System Design (Clause 3.8)

• Prevent run-off, over-watering, and irrigation beyond target zones.
• Water meter mandatory; daily water records required.
• Max precipitation rate ≤ 19 mm/hr.
• Separate valves for sprinklers, drip, bubblers.
• Anti-drain valves/check valves to prevent low-head drainage.
• No overhead irrigation within 0.6 m of non-permeable surfaces.
• Embed irrigation pipes at 0.3-0.6 m depth; backfill coverage:
  • Street/planter beds: 300-400 mm
  • Under carriageways: 450-600 mm
• Prefer drip irrigation for water conservation.
• Manual overrides and soil moisture checks recommended.

2. Water Use Estimate (WUE) Calculation (Clause 2.36)

[ \text{Water requirement (L/day)} = \frac{2.36 \times A_c \times ET_p \times F_p}{IE} ]

3. Tables

Tree Pits within Medians – IRC SP 119 Key Specifications

• Minimum Tree Pit Size:

  • Area: 3.3 m²
  • Minimum dimension: 1.8 m in any direction
  • Depth: 1.2 m

• Median Specifics:

  • Minimum internal width: 1 m in any direction
  • Retained by:
    • Brick wall: 230 mm thick
    • Concrete wall: 75 mm thick
  • Retention prevents damage to road sub-grade

• Plantation Guidelines:

  • Small to medium trees in medians with above pit size
  • For medians <1 m wide: use ground cover + shrubs ≤0.6 m height (pruned)
  • Tree line orientation: Prefer sunnier side (South/West) on narrow streets
  • Group trees/shrubs by hydrozone for water efficiency
  • Cover soil with mulch/ground cover to minimize dust re-suspension

• Tree Clearance to Utilities (Table 6):

Typical Tree Pit (Fig. 94) Key Features:

• Root ball depth with 150-300 mm undisturbed soil below
• Wooden stakes: 2.2 m length, inserted into undisturbed soil
• Mulch depth: 75 mm
• Root barrier at kerbs for root control

flowchart LR
    A[Median] --> B[Tree Pit (min 1m width)]
    B --> C[Retaining Wall]
    C -->|Brick 230mm| D[Road Sub-grade Protection]
    C -->|Concrete 75mm| D
    B --> E[Tree with Root Ball]
    E --> F[Wooden Stakes 2.2m]
    E --> G[Mulch 75mm]
    E -->

IRC SP 119: Typical Details for Street Furniture (Clauses 2.4 & 3.6)

Key Points:

• Street Furniture includes bollards, benches, paving, boundary walls, cycle parking, etc.
• Positioned in the Multi-Functional Zone to avoid obstruction of walking and non-motorized traffic (NMT) spaces.
• Can be placed in resting islands or integrated with tree lines for safety and usability.

Specifications:

• Multi-Functional Zone Width: Typically varies, but must accommodate furniture + cycle parking without encroaching pedestrian or NMT zones.
• Clearance: Maintain minimum clear walking width (usually 1.8m to 2.0m) free of furniture.
• Furniture Placement:
  • Bollards: Positioned to prevent vehicle intrusion but allow pedestrian flow.
  • Benches: Minimum seat height ~450mm, length ~1200-1500mm.
  • Paving: Use tactile paving near furniture for accessibility.

Typical Dimensions (Recommended):

Placement Diagram (Simplified):

flowchart LR
    A[Roadway] --> B[Multi-Functional Zone]
    B --> C[Resting Island with Benches & Bollards]
    B --> D[Cycle Parking]
    B --> E[Tree Line Integration]
    C --> F[Pedestrian Walkway (≥1.8m clear)]

Summary:

• Locate street furniture in the multi-functional zone.
• Ensure clear pedestrian and NMT paths.
• Use standard dimensions for comfort and safety.
• Integrate with landscape elements for aesthetics and functionality.

For detailed drawings, refer to Figures 31 & 32 in IRC SP 119-2018.

Kerb Details for Bio-infiltration Zones (IRC SP 119: Clause 3.7.1)

Key specifications and design guidelines for kerbs facilitating stormwater flow into bio-infiltration zones:

Kerb Cut Dimensions & Specifications:

• Kerb cut width: 450 mm
• Kerb cut sides: Chamfered at 45° to direct flow and reduce erosion
• Minimum drop: 2° slope from finished road/parking level to finished landscape grade
• Side wings (Kerb Type 2): Help retain side slope grade, minimum 200 mm drop from road/parking level to landscape
• Materials: Gravel mulch at kerb cut opening to prevent erosion and filter stormwater

Kerb Types:

Functional Notes:

• Slope kerb entry points to direct runoff into infiltration basins or bio-swales.
• Use gravel mulch (stable, 40-80 mm Ø stones) at kerb cuts to prevent erosion and filter pollutants.
• Kerb height must allow stormwater to flow into bio-filtration beds without damaging footpath or carriageway subgrade.

Summary Diagram of Kerb Cut Section (Kerb Type 1 example):

flowchart LR
    A[Street/Parking Lot Surface (Fin. Level ±0)] -->|2° slope| B[Kerb Cut (450 mm wide)]
    B --> C[Gravel Mulch (stable filter)]
    C --> D[Landscape Area (Lower Grade)]
    B -.->|Chamfered Sides 45°| E[Side Wings (if Type 2)]

Additional Notes:

• Bio-swales and infiltration trenches should be integrated with kerb cuts.
• Ensure kerb cut slope and width accommodate expected runoff volume.
• Refer to Figs. 119-122 in IRC SP 119 for detailed kerb cut geometries and installation.

This kerb design facilitates effective stormwater conveyance into bio

Subgrade Protection from Median Plantation - IRC SP 119 Key Points

1. Subgrade Protection from Median Plantation (Clause 3.9.1 & 3.9.2)

• Issue: Tree roots deliver water to subgrade causing subsidence.
• Solution: Trees planted inside cylindrical pipes to direct roots deeper, preventing lateral root intrusion.
• Fig. 138 shows:
  • Cast in situ block: 190 x 200 mm
  • Deep groove on two sides for root guidance
  • Final road level with compacted soil and tree pit excavation line

2. Median Plantation Specifications (Clause 4.5 & Table 2.5)

• Clear height above road: Minimum 4.5 m pruning for existing trees.
• Avoid: Monoculture, low-branching trees, exposed soil.
• Plant species: Thorny, flowering shrubs (e.g., Bougainvillea, Kaner), ground covers (e.g., Cynodon dactylon).

3. Additional Notes

• Bio-swales recommended in low water table areas for recharge and flood control.
• Avoid raised mounds on traffic islands to prevent runoff.
• Soil must be covered with mulch or plantation to prevent erosion.

Summary Diagram: Median Width vs Plantation Type

graph TD
  A[Median Width <1m] --> B[Ground cover + Shrubs (0.6m)]
  C[Median Width 1-2m] --> D[Two rows shrubs + ground cover (1.5m)]

IRC SP 119: Maintenance Lifecycle & Activities Summary

1. Maintenance Lifecycle Phases (Clause 4.2)

• Before planting: Survey, clean site, dig pits, procure materials.
• Up to 10 years after planting: Watering, weeding, hoeing, casualty replacement (20% in 3rd year, 10% in 4th year), fencing, manure application.
• Long-term maintenance: Regular watering, weeding, and replacement as needed.

2. Key Activity Schedule (Table 19 - Arboriculture Regime)

3. Transplantation of Large Trees (Clause 3.11.1 & Table 18)

• Timing: Dormant season (July-Aug best)
• Preparation: Heavy pruning, trenching, root stimulation
• Handling: Wrap root ball, protect crown, use cranes
• Aftercare: Multi-year watering and monitoring
• Success Factors: Age, health, site match, expertise, equipment

4. Monitoring Parameters (Table 20)

Summary Diagram: Maintenance Lifecycle

graph TD
    A[Before Planting] --> B[1st Year Activities]
    B --> C

Minimizing Damage During Plantation — IRC SP 119 Key Points

Handling & Planting (Clause 4.3.1)

• Inspect plants before, during, and after planting.
• Plant pits must be approved and properly prepared.
• Handle balled & burlapped/container plants by soil ball only; never drag or lift by trunk/foliage.
• During transport, secure plants to prevent wind/vibration damage; never throw or bounce plants.
• Plant on delivery day or water & mulch to prevent dehydration.
• Protect trunks prone to scarring with non-abrasive wraps; treat any damage immediately.
• Avoid moving plants during active growth unless ball size ensures survival.
• Tie bushy evergreens to protect foliage during transport; untie after planting.

Storm & Wind Protection (Clauses 2.7.12, 3.5.5)

• Plant deep-rooted, slow-growing native trees with small leaves.
• Use cluster planting with spacing < 6 m c/c for shelter belts.
• Avoid planting in storm-prone areas with shallow-rooted or columnar trees.
• Provide staking with 3 stakes (2 m length, 60 mm dia or 50x50 mm wood), buried 50 cm deep.
• Stakes tied with cotton to prevent trunk sway; remove stakes within 1 year.
• Use deadman guys at 120° intervals for extra stability in windy areas.

Planting Pit & Backfill

• Maintain pit diameter for watering and root anchorage.
• Roughen pit sides to encourage root growth.
• Backfill with moist soil; create an earth saucer around the pit for water retention.
• Ensure tree is plumb before staking.

Summary Table: Staking Specifications

Illustration: Tree Staking Arrangement

graph TD
    A[Tree Trunk] -->|T

IRC SP 119 - Committee Composition and Approval Process

Committee Composition (As per IRC:SP:119-2018)

• Highways Specifications & Standards Committee (HSS):

  • Convenor: Director General (Road Development), MoRTH
  • Co-Convenor: Additional Director General, MoRTH
  • Member Secretary: Chief Engineer (R) S,R & T, MoRTH
  • Members: Senior officials from MoRTH, PWDs, IITs, BIS, NHAI, CRRI, Border Roads Organisation, and experts from academia and industry.
  • Corresponding Members: Experts from Institutes like Institute of Road Traffic Education, retired engineers, and consultants.

• Sub-Committees (e.g., Urban Roads and Streets H-8 Committee):

  • Convenor, Co-Convenor, Member Secretary, and members from diverse relevant backgrounds.
  • Responsible for drafting specific manuals (e.g., Manual for Planting and Landscaping of Urban Roads).

Approval Process

1. Draft Preparation: By sub-groups/sub-committees with expert members.
2. Discussion & Inputs: Multiple meetings with committee members and stakeholders.
3. Committee Approval: HSS Committee reviews and approves the draft.
4. Executive Committee Approval: Further consideration and approval.
5. Council Approval: Final approval for printing and publication.

Key Points

• The committee includes multidisciplinary experts ensuring comprehensive standards.
• Approval is iterative, involving detailed review at multiple levels.
• The process ensures technical accuracy, practical relevance, and stakeholder consensus.

flowchart TD
    A[Sub-Group Draft Preparation] --> B[Discussion & Inputs]
    B --> C[HSS Committee Approval]
    C --> D[Executive Committee Approval]
    D --> E[Council Approval]
    E --> F[Publication]

This structured approach guarantees robust, consensus-based standards for highway specifications and landscaping.