Type Designs for Pick-Up Bus Stops on Rural (i.e., Non-Urban) Highways

IRC 80 - Introduction: Key Points

• Scope: IRC 80 covers standard designs and specifications for road bridges, finalized through extensive committee reviews (1979-1981).
• Design Basis: The code provides guidelines for layout, design, and construction of bridges, ensuring safety and durability.
• Committee: Developed by experts (R.P. Sikka, Dr. N.S. Srinivasan) and approved by the Executive Committee and Council in 1981.
• Publication: First published in December 1981; reprinted in April 2007.

Important Notes:

• IRC 80 primarily sets standardized designs rather than detailed formulas.
• For design calculations, refer to related IRC codes like IRC 6 (Loading) and IRC 21 (Concrete Bridges).
• Layout and design principles emphasize site suitability, traffic loading, and structural efficiency.

Typical Design Considerations Include:

• Span length and type selection
• Load factors and impact coefficients
• Material specifications (concrete, steel)
• Safety factors as per IRC guidelines

Summary Table: IRC 80 Publication

For detailed formulas and load tables, consult IRC 6 and IRC 21 alongside IRC 80.

IRC 80: Scope Summary

• Scope: IRC 80 provides standardized type designs for the siting and layout of wayside pick-up bus stops on roads.
• Purpose: To ensure uniformity and safety in bus stop design, facilitating smooth traffic flow and passenger convenience.
• Applicability: Recommended for general adoption across road projects involving bus stop layouts.
• Development: Formulated by the Specifications and Standards Committee with expert inputs and finalized in 1981.

Key Specifications (General)

Typical Design Considerations

• Bus Bay Length: Sufficient for bus length + clearance (~15-18 m)
• Bus Bay Width: Minimum 3.0 m to accommodate bus width
• Approach and Departure Sight Distances: As per IRC guidelines for safe stopping and merging
• Pedestrian Access: Safe and convenient access paths

flowchart LR
    A[Road with Traffic Flow] --> B[Bus Stop Location]
    B --> C{Bus Bay Design}
    C --> D[Length & Width per IRC 80]
    C --> E[Sight Distance Criteria]
    C --> F[Passenger Access]

For detailed tables and exact dimensioning, refer to IRC 80 full text under "Layout and Design" clauses.

IRC 80: Need for Laybyes – Key Points

• Purpose: Laybyes provide safe stopping space for buses without obstructing through traffic.

• Factors Influencing Need (Clause 3.1):

  • Traffic volume
  • Frequency & duration of bus stops
  • Number of passengers boarding/alighting

• Typical Locations (Clause 3.2):
  Separate laybyes are justified on important trunk routes (National & State Highways) when:

  • High bus frequency
  • Long halt durations
  • Significant passenger activity

• Layout Selection (Clause 5.1):

  • Based on number of buses stopping simultaneously
  • Period of halt
  • Traffic volume on main road
  • Consult bus authorities for operational details

Typical Laybye Dimensions (IRC Recommendations)

Formula for Laybye Length Estimation

[ L = n \times L_b + L_s ]

Where:

• (L) = total laybye length
• (n) = number of buses expected simultaneously
• (L_b) = length of one bus (typically 12 m)
• (L_s) = additional space for maneuvering (5-10 m)

flowchart LR
    A[Traffic Volume] --> B{Need for Laybye?}
    C[Bus Stop Frequency] --> B
    D[Duration of Halt] --> B
    E[Passenger Activity] --> B
    B -->|Yes| F[Design Laybye Layout]
    F --> G[Consult Bus Authorities]
    F --> H[Determine Dimensions]

Summary: Laybyes improve traffic flow and safety on busy roads by segregating stopping buses. Design must consider local traffic, bus operations, and passenger needs per IRC 80 guidelines.

IRC 80: General Principles of Location for Wayside Pick-up Bus Stops

While IRC 80 does not provide explicit formulas, it emphasizes standardized siting and layout to ensure safety and efficiency.

Key Specifications & Principles:

• Location Criteria:

  • Bus stops should be on straight road sections or gentle curves for visibility.
  • Avoid locations near intersections, sharp curves, or steep gradients.
  • Ensure adequate sight distance for safe deceleration and acceleration.

• Layout Guidelines (Fig I - Typical Layout):

  • Bus Bay Length: Minimum 30 m (to accommodate bus length + maneuvering).
  • Bus Bay Width: 3.5 m (to allow safe parking without obstructing traffic).
  • Entry/Exit Tapers: 15-20 m for smooth merging.
  • Passenger Waiting Area: Clear, sheltered space adjacent to the bus bay.

Recommended Design Checklist:

• Visibility ≥ 150 m in both directions.
• Minimum stopping sight distance as per IRC 6.
• Safe pedestrian access and waiting zones.
• Proper drainage and lighting.

flowchart LR
    A[Road Alignment] --> B{Bus Stop Location}
    B -->|Straight/Gentle Curve| C[Safe Sight Distance]
    B -->|Avoid| D[Intersections/Sharp Curves]
    C --> E[Bus Bay Design]
    E --> F[Length ≥ 30m]
    E --> G[Width ≥ 3.5m]
    E --> H[Entry/Exit Tapers]
    F --> I[Passenger Waiting Area]

Summary: Follow IRC 80's recommended layouts ensuring visibility, adequate bay dimensions, and safe pedestrian zones for effective bus stop location.

IRC 80: Layout and Design of Bus Lay-byes

Key Points from IRC 80 (Clauses 5 & related):

• Layout Selection Factors:

  • Number of buses stopping simultaneously
  • Duration of bus halts
  • Traffic volume on the road
  • Passenger alighting numbers
  • Local site conditions and consultation with bus authorities

• Typical Layouts:

  • Figures 1 to 3 (in IRC 80) provide standard layouts for wayside bus stops.
  • Layouts include:
    • Bus bays for buses to pull out of traffic
    • Bus shelters and passenger waiting areas
    • Pedestrian access and safety zones

Design Specifications (General):

Design Approach:

1. Assess local traffic and passenger data.
2. Select layout type from IRC standard figures.
3. Dimension bays to fit bus length and maneuvering.
4. Provide safe pedestrian access and visibility.
5. Consult bus operators for operational needs.

flowchart LR
    A[Assess Traffic & Passenger Data] --> B[Select Layout Type]
    B --> C[Dimension Bus Bay]
    C --> D[Design Pedestrian Access]
    D --> E[Consult Bus Authorities]
    E --> F[Finalize Layout & Design]

For detailed dimensions and layouts, refer to IRC 80 figures 1-3 and associated notes.

IRC 80 - Paving of Laybye Area: Key Points & Specifications

1. Pavement Design

• Adequate crust thickness must be provided based on expected wheel loads.
• Surfacing must resist frequent braking and acceleration forces from buses.
• Laybye surfacing should have distinctive color and texture compared to the main carriageway for visibility.

2. Shoulder Paving near Laybyes

• Shoulders near laybyes should be paved to allow occasional parking and proper drainage.
• Materials recommended:
  • Brick on edge
  • Lean cement concrete / fly ash concrete / lime-fly ash concrete (cast-in-situ or precast)
  • Precast tiles
  • Stone slabs/blocks
  • Water bound macadam with surface dressing
• Paved shoulders must be flush with carriageway surface and sloped away for drainage.
• If shoulder and pavement colors are same, edge lines per IRC:35-1970 should be provided.

3. Layout Selection

• Refer to Figures 1-3 in IRC 80 for typical laybye layouts.
• Selection depends on:
  • Number of buses stopping simultaneously
  • Halt duration
  • Road traffic volume
  • Passenger alighting numbers
• Consultation with bus authorities is recommended.

Summary Table: Materials for Shoulder Paving

flowchart LR
    A[Laybye Pavement] --> B{Design Requirements}
    B --> C[Adequate Crust Thickness]
    B --> D[Resist Braking & Acceleration]
    B --> E[Distinctive Color & Texture]
    A --> F[Should

IRC 80: Passenger Shelters and Amenities – Key Points

• Shed Design (Clause 5.4):

  • Only passenger sheds allowed at bus stops.
  • Must be structurally safe, aesthetic, and functional.
  • Provide protection from sun, wind, and rain.
  • On hillsides, slopes must be dressed and protected against slips.
  • Set back from kerb line by ≥ 0.25 m.

• Layout and Siting (Clause 1.2 & Fig. 3,4):

  • Use standardized type designs for wayside pick-up bus stops.
  • Layout includes footpaths, paved shoulders, pedestrian crossings.
  • Staggered bus stop layouts recommended for traffic flow and safety.

• Drainage (Clause 7.1):

  • Laybyes must have proper cross slope to drain water away.
  • Avoid water pooling near shelters to prevent splashing on passengers.

Typical Cross Slope for Drainage:

• Cross slope: 2% (1:50) minimum to ensure runoff.

Recommended Setbacks and Dimensions:

flowchart TB
    A[Bus Stop Location] --> B[Laybye with Cross Slope]
    B --> C[Passenger Shelter Setback ≥ 0.25 m]
    C --> D[Protected Slopes (if hillside)]
    D --> E[Pedestrian Crossing & Footpath]
    E --> F[Drainage Away from Shelter]

Summary: Design bus shelters per IRC 80 ensuring safety, aesthetics, functional protection, proper drainage, and standardized layout for passenger comfort and operational efficiency.

IRC 80: Road Markings and Signage - Key Points

• Reference for Road Markings:
  For detailed specifications on road markings, refer to IRC 35-1970 which covers types, dimensions, and materials.

• Bus Stop Markings (Clause 1.2):
  IRC 80 provides standardized type designs for wayside pick-up bus stops on rural highways, including:

  • Siting and layout recommendations
  • Dimensions for bus stop bays and markings

• Maintenance (Clause 8.3):
  Road markings must be regularly maintained to ensure visibility and safety.

Summary Table: Typical Bus Stop Marking Dimensions (Indicative)

Recommended Marking Types (from IRC 35-1970):

• Longitudinal lines: Solid or broken white lines, width 100-200 mm
• Transverse markings: Stop lines, zebra crossings
• Symbols: Bus stop symbols painted in white within the bay

flowchart LR
    A[Highway] --> B[Bus Stop Bay]
    B --> C[Longitudinal Markings]
    B --> D[Bus Stop Symbol]
    B --> E[Stop Line]

For full details, consult IRC 35-1970 and the bus stop type designs in IRC 80.

Safety and Visibility Considerations (IRC 80)

IRC 80 emphasizes safe siting of bus stops with respect to visibility and safety:

• Location Restrictions:

  • Avoid bus stops near bridges, important structures, or embankments >4 m high.
  • Avoid horizontal curves and summit vertical curves for bus stops.

• Visibility:

  • Ensure Stopping Sight Distance (SSD) is maintained around bus stops for safe vehicle stopping.

• Reference for Road Markings:

  • IRC:35-1970 provides detailed guidelines on road markings enhancing visibility and safety.

Key Formula: Stopping Sight Distance (SSD)

[ SSD = d_r + d_b ]

Where:

• ( d_r = ) Distance traveled during driver reaction time
• ( d_b = ) Braking distance

[ d_r = v \times t_r ]

[ d_b = \frac{v^2}{2gf} ]

• ( v = ) speed (m/s)
• ( t_r = ) reaction time (usually 2.5 s)
• ( g = 9.81 , m/s^2 )
• ( f = ) coefficient of friction (typically 0.35 to 0.4 for wet pavement)

Typical SSD Values (for design speeds):

Summary:

• Site bus stops on tangents with clear visibility equal to SSD.
• Avoid locations with restricted sight distance.
• Use IRC:35-1970 for road marking standards to enhance visibility.

flowchart LR
    A[Bus Stop Location] --> B{Visibility Check}
    B -->|SSD Adequate| C[Safe Stop]
    B -->|SSD Inadequate| D[Relocate Bus Stop]
    C --> E[Apply Road Markings (IRC:35-1970)]
    D --> E

This ensures safe stopping and clear visibility at bus stops.

Special Considerations for Bus Stops in Hilly Areas (IRC 80):

• Location Criteria:

  • Preferably on straight road sections with flat gradients.
  • Visibility not less than 50 meters on both sides.
  • Economical possibility to widen the roadway for bus lay-byes and shelters.

• Gradient & Visibility:

  • Flat gradients ensure safe stopping and starting.
  • Adequate visibility reduces accident risk.

• Road Widening:

  • Provide space for bus lay-byes without obstructing traffic.
  • Space for passenger shelters must be considered.

• Drainage:

  • Along kerbed edges, provide kerb-gutter with proper longitudinal slope.
  • Include outlets at intervals for efficient water disposal.

Summary Table for Bus Stop Location in Hilly Terrain

flowchart LR
    A[Bus Stop Location] --> B[Straight Road Section]
    A --> C[Flat Gradient]
    A --> D[Visibility ≥ 50m]
    A --> E[Road Widening for Lay-byes]
    A --> F[Passenger Shelters]
    A --> G[Kerb-Gutter with Drainage]

This ensures safety, comfort, and traffic flow efficiency in hilly terrain bus stop design.