Designing for Safety

Demonstrating best practices for road design in the urban Indian

contextBinoy Mascarenhas

Manager – Urban TransportEMBARQ India

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people lost their lives on our roads in 2013

140,000+

Road fatalities in India

Pedestrians + Motorised 2-wheelers

typically make up half of road fatalities in cities

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What’s causing these accidents?

Human

ExternalVehicle

An accident is a rare, random,

multi-factor event

If one of the factors is corrected, it is likely that the accident would not happen, or at least, its

severity would be reduced

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What are the external factors?

Road conditions Geometry (alignment, elevation, area allocation, etc.) Pavement condition (debris, potholes, wetness, etc.) Signage & lane marking Provisions (crossings, U-turns, turning lanes, parking,

etc.) Lighting & visibility

Traffic conditions Speed Volume Mix Turning movements

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The role of junctions

Although junctions take up only a fraction of road space, they

typically account for more than half of all road accidents

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Guideline design template for junctions

Generally provided for 4-arm intersectionsRoads meet at perfect right anglesRoad width is constant across the junctionNo obstacles / encroachments on road spaceCo-planar geometry

Sometimes junctions do not meet these ideal conditions.

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Typical issues with junctions

Very large junction area

5+ arms

Roads meet at skewed angles

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Typical issues with junctions

No proper lane balance & alignment

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Typical issues with junctions

Pedestrians sharing path with traffic

Wide roads leading into narrow roads

Wide kerb radius

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Typical issues with junctions

No designated pedestrian crossings

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Typical issues with junctions

Often, road resurfacing and laying of footpath ceases just before the junction

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Thane junction improvementCase of Nitin Chowk junction

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Site location

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Existing geometry

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Pedestrian movement

Underutilised subway Pedestrians cross at-grade

No pedestrian crossing islands

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Pedestrian movement

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Ancillary road uses

Private bus pickup/drop-off Bus U-turn in the intersection

Unused auto rickshaw stand Illegal 2-wheeler parking

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Ancillary road uses

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Turning movements

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2-way service roads

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Multiple conflict points

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Wide undefined intersection area

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Design process

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Design decisions

Service roads are meant for local access; main lanes are for through movement

Use internal streets for local movement between service roads

Traffic below the flyover to be slowed down to allow for safe at-grade pedestrian crossings

Maintain lane balance & alignment on opposite sides of the intersection

Reduce intersection area, by advancing stop lines and tightening corners

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Recommended design

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Recommended design

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At-grade pedestrian crossings

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Service road entry to main lanes

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Use of internal streets to bridge connections

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U-turns after the intersection

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Proposed design

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Proposed signal plan

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Lessons learned

Junction design needs to be contextual. Rather than a standard design, a standardised process for design is required

The solution often lies beyond the junction area (traffic re-routing)

Service roads are meant purely for access, not for thoroughfare. They should NOT continue through the junction

Subways and FOBs will not work if they involve a significantly greater effort than the natural at-grade crossing path

Junction safety can be improveed while simultaneously increasing capacity

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THANK YOU!