Space Standards for Roads in Urban Areas

IRC 69: Introduction - Key Specifications & Tables

1. Road Classification & Functions

• Expressways & Arterial Streets: Major through traffic routes; spacing varies from <1.5 km (CBD) to 8 km+ (urban fringe). Usually divided highways with restricted parking/loading.
• Sub-arterial Streets: Lower mobility than arterials; spacing 0.5 km (CBD) to 3-5 km (suburbs).
• Collector Streets: Collect traffic from local streets; full access allowed; minimal parking restrictions.
• Local Streets: Provide direct property access; unrestricted parking and pedestrian movement.

2. Recommended Land Widths (Table 1)

3. Typical Cross-Sections

• Guidance provided in IRC 69 (Figs. 1-11).
• Include space for roadside trees, utilities, side drains.
• Dimensions adjustable for traffic intensity and additional facilities.

flowchart TD
    A[Expressways/Arterial Streets] -->|Spacing| B(<1.5km to 8km+)
    C[Sub-arterial Streets] -->|Spacing| D(0.5km to 5km)
    E[Collector Streets] -->|Function| F(Collect traffic from local streets)
    G[Local Streets] -->|Function| H(Access to properties)

Summary: IRC 69 emphasizes functional classification, spacing, and land width standards for urban roads to ensure efficient traffic movement and urban development compatibility.

IRC 69: Scope and Application - Key Specifications

1. Classification & Function

• Expressways & Arterial Streets: Main through traffic routes; spacing varies from <1.5 km (CBD) to >8 km (urban fringes).
• Sub-arterial Streets: Lower mobility than arterial; spacing 0.5 km (CBD) to 3-5 km (suburbs).
• Collector Streets: Collect traffic from local streets; full access allowed.
• Local Streets: Provide direct property access; low traffic volume.

2. Recommended Land Width (Table 1)

3. Cross-Sections

• Typical cross-sections (Figs. 1-11) accommodate trees, utilities, and drainage.
• Dimensions can be increased based on traffic intensity and additional facilities.

flowchart TD
    A[Expressways & Arterial Streets] -->|Traffic distribution| B[Sub-arterial Streets]
    B -->|Lower mobility| C[Collector Streets]
    C -->|Collect traffic| D[Local Streets]
    D -->|Access to property| E[Pedestrian & Parking]

This classification ensures efficient traffic flow and appropriate space allocation per urban context.

Classification of Streets (IRC 69)

1. Categories & Functions

• Expressways: High-speed, limited access, for through traffic.
• Arterial Streets: Major roads for through traffic; spacing:
  • CBD: <1.5 km
  • Urban fringe: ≥8 km
  • Divided highways, restricted parking/loading.
• Sub-arterial Streets: Lower mobility than arterial; spacing:
  • CBD: ~0.5 km
  • Suburban: 3-5 km
• Collector Streets: Collect traffic from local streets to arterials; full access, limited parking restrictions.
• Local Streets: Provide property access; low traffic volume, unrestricted parking.

2. Recommended Land Width (Table 1)

3. Cross-Sections

• Refer to IRC 69 Figs. 1-11 for typical layouts.
• Include space for roadside trees, utilities, and drainage.
• Adjust dimensions based on traffic and urban needs.

graph TD
    A[Expressways] -->|High speed| B[Arterial Streets]
    B -->|Moderate speed| C[Sub-arterial Streets]
    C -->|Lower speed| D[Collector Streets]
    D -->|Access roads| E[Local Streets]

Note: Street spacing and widths ensure efficient traffic flow and urban development compatibility.

Functions and Specifications of Different Street Systems (IRC 69)

1. Functions of Street Systems

2. Recommended Land Widths for Urban Streets

3. Cross-Section Guidelines

• Cross-sections (Figs. 1-11 in IRC 69) accommodate traffic, roadside trees, utilities, and drainage.
• Adjust dimensions based on traffic intensity and additional requirements.

flowchart TD
    A[Local Streets] --> B[Collector Streets]
    B --> C[Sub-arterial Streets]
    C --> D[Arterial Streets]
    D --> E[Expressways]
    style A fill:#f9f,stroke:#333,stroke-width:2px
    style E fill:#bbf,stroke:#333,stroke-width:2px

Summary: Street systems are hierarchical, designed for efficient traffic flow, access, and land use, with specific spacing and width standards ensuring functional urban mobility.

IRC 69: Space Requirements for Different Categories of Streets

Key Specifications (Table 1: Recommended Land Width for Urban Streets)

Spacing & Functional Notes:

• Arterial Streets: Spaced <1.5 km in CBD, up to 8 km in urban fringes; divided highways with regulated parking.
• Sub-arterial Streets: Spaced 0.5 km (CBD) to 3-5 km (suburbs); lower mobility than arterial.
• Collector Streets: Connect local streets to arterials; full access; limited parking restrictions.
• Local Streets: Primarily for property access; unrestricted parking and pedestrian movement.

Design Considerations:

• Widths depend on traffic volume, land use, future development, and travel modes.
• Cross-sections should accommodate roadside trees, utilities, and drainage.
• Adjust widths for additional facilities as needed.

flowchart LR
    Expressways --> Arterial
    Arterial --> Sub-arterial
    Sub-arterial --> Collector
    Collector --> Local

This hierarchy ensures efficient traffic distribution and land use compatibility.

Recommended Land Widths for Streets (IRC 69)

Key Points:

• Arterial streets: Spaced less than 1.5 km in CBD, up to 8 km in urban fringes; generally divided highways with restricted parking.
• Sub-arterial streets: Spacing 0.5 km (CBD) to 3-5 km (suburbs), lower mobility than arterial streets.
• Collector streets: Collect traffic from local streets; full access allowed, limited parking restrictions.
• Local streets: Primarily for property access, unrestricted parking and pedestrian movement.

Cross-Section Guidance:

• Typical cross-sections accommodate roadside plantations, utilities, and side drains.
• Dimensions should increase if additional facilities are needed.

flowchart LR
    A[Expressways] -->|50-60m| B[Arterial Streets]
    B -->|50-60m| C[Sub-arterial Streets]
    C -->|30-40m| D[Collector Streets]
    D -->|20-30m| E[Local Streets]
    E -->|10-20m| F[Property Access]

This table and guidance help ensure efficient traffic movement and adequate space for utilities and pedestrian safety.

IRC 69: Typical Cross-Sections & Space Requirements for Urban Roads

1. Recommended Land Widths (Table 1)

2. Key Specifications for Cross-Sections (Clause 7)

• Cross-sections must accommodate:
  • Traffic lanes (number depends on traffic volume)
  • Roadside plantations (trees)
  • Utility services (water, electricity, drainage)
  • Side drains for stormwater
• Dimensions can be increased for additional facilities.
• Cross-sections should be flexible for staged development.

3. General Guidance for Cross-Section Elements

• Carriageway width: Based on traffic volume; arterial roads typically have multiple lanes (7.5 m per lane).
• Footpaths: Minimum 1.5 to 2.0 m on both sides.
• Median: Provided on arterials and expressways, width varies from 3 to 6 m.
• Shoulders: Usually 1.5 to 2.5 m on both sides for collector and arterial streets.

graph LR
A[Road Cross-Section] --> B[Carriageway (Lanes)]
A --> C[Median]
A --> D[Footpath]
A --> E[Shoulders]
A --> F[Utility Services & Drainage]

For detailed figures (Figs. 1-11), refer to IRC 69 Annexures for typical layouts.

IRC 69: Access Control & Parking Regulations - Key Points

1. Access Control by Road Category

• Expressways & Arterial Streets:

  • Full or partial access control.
  • Parking, loading/unloading usually restricted or regulated.
  • Pedestrians cross only at intersections.

• Sub-arterial Streets:

  • Similar to arterial but with lower mobility.
  • Access control less strict than arterial.

• Collector Streets:

  • Full access allowed to abutting properties.
  • Parking generally allowed except peak hours.

• Local Streets:

  • Unrestricted parking and pedestrian movement.
  • Primarily provide access to properties.

2. Recommended Land Widths (Table 1)

3. Parking Regulations Summary

• Arterial & Expressways: Parking/loading restricted to maintain traffic flow.
• Collector Streets: Parking allowed except during peak hours.
• Local Streets: Parking unrestricted.

4. Cross-Section Guidance

• Typical cross-sections (IRC 69 Figs. 1-11) accommodate trees, utilities, and drains.
• Adjust width if additional facilities are needed.

graph LR
A[Expressways/Arterial] -->|Restricted Parking| B[Access Control]
B --> C[Pedestrian crossing only at intersections]
D[Collector Streets] -->|Parking allowed except peak| E[Full Access]
F[Local Streets] -->|Unrestricted Parking| G[Access to properties]

Summary: IRC 69 emphasizes access control and parking restrictions mainly on arterial and expressway roads to ensure smooth traffic flow, while allowing more flexible parking and access on collector and local streets.

Integration of Roads with Land Use & Urban Development (IRC 69)

Key Specifications & Space Standards

Key Points:

• Continuity of arterial streets is essential for efficient traffic flow.
• Spacing varies with urban density: closer in CBD, wider in suburbs.
• Cross-sections should allow for plantation, utilities, and drainage.
• Street widths and cross-sections must be adjusted based on traffic intensity and land use.

Typical Cross-Section Elements (General Guidance)

• Carriageway width depends on traffic volume.
• Footpaths for pedestrians.
• Plantation strips for roadside trees.
• Utility service corridors.
• Side drains for stormwater.

graph TD
    A[Land Use Zones] --> B[Local Streets]
    B --> C[Collector Streets]
    C --> D[Sub-arterial Streets]
    D --> E[Arterial Streets]
    E --> F[Expressways]

    style A fill:#f9f,stroke:#333,stroke-width:1px
    style F fill:#bbf,stroke:#333,stroke-width:1px

This hierarchy ensures smooth traffic distribution aligned with urban development patterns.

IRC 69: Traffic Safety & Environmental Considerations — Key Specifications

1. Space Standards & Road Categories

2. Traffic Safety Considerations

• Continuity of arterial streets ensures smooth through traffic.
• Pedestrian crossings restricted to intersections on arterials to reduce conflict points.
• Parking/loading restrictions on arterials and expressways improve safety and flow.
• Full access allowed on collectors and locals, balancing access and safety.

3. Environmental Considerations

• Provision for plantation of roadside trees included in typical cross-sections.
• Space for utility services and side drains incorporated.
• Cross-sections adaptable to include additional environmental facilities.

Typical Cross-Section Guidance

• Cross-sections should allow for:

  • Roadway lanes
  • Footpaths
  • Plantation strips
  • Utility corridors
  • Side drains

• Dimensions can be increased based on traffic intensity and environmental needs.

flowchart LR
    A[Expressway] -->|50-60m| B(Arterial)
    B -->|50-60m| C(Sub-arterial)
    C -->|30-40m| D(Collector)
    D -->|20-30m| E(Local)
    E -->|10-20m| F[Property Access]

Summary: IRC 69 emphasizes adequate land width per street category, controlled pedestrian and vehicle access on arterials for safety, and environmental provisions like tree plantations and drainage in urban road design