This Presentation is a brief overview for the feasibility study that was conducted for the implementation of a 2+1 road design along the Curra to Tinana Interchange section of the Bruce Highway.
The Feasibility of a 2+1 Solution for the Bruce Highway: Curra to the Tinana Interchange
1. Feasibility Study for a
2+1 Design Solution
for the Bruce
Highway:
Curra to the Tinana
Interchange
BEB801 Project 1 103/06/2016
BEB801 Project 1
Source: Wikipedia, (2015)
James Wilkinson
2. ‘Out of Crisis’
The Bruce Highway is the most dangerous road
in Australia
Bruce Highway Action Plan: ‘Out of Crisis’
• $8.5 billion for upgrades to the 1700km
highway
• Fatal crash rate of 0.2853 per km of road
per year (17 fatalities per year on average)
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Source: Metcalfe et al, (2005)
3. Curra to the Tinana Interchange
62.4km length and 8m wide pavements
Generally undulating terrain with two
‘mountainous’ sections
10,000 AADT
No major upgrade planned in the next 20
years – only a 12.5m pavement widening
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4. Features of the 2+1 Design
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Source: National Road Authority, (2004)
Third continuous overtaking lane
Widened central median generally
with a cable barrier
Critical / Non-Critical Lane
changeovers for equal overtaking
opportunities
Left in / left out manoeuvres only
6. Intersection Features
Generally will occur at lane changeovers
Directional traffic will drop to one lane each way
Due to left in / left out operations between intersections
U turn facilities are required
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Source: National Roads Authority, (2004) Source: Gazzini, (2008)
7. Outcomes of 2+1 Highway Design
Significant reductions in fatal crashes
(>50%)
Elimination of head on crashes
Reductions in overtaking and run-off
accidents
Bottlenecks at lane changeover point
area concern
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Roadway Type Fatality Rate
2 lane Rural
Highway
0.28
2+1 Roadway 0.16
4 Lane Divided
Highway
0.19
Source: Potts et al, (2003)
8. 2+1 Road Design Suitability
Generally flat / rolling terrain
AADT within 5,000 to 15,000 optimal
range
Significant reduction in fatal and severe
accidents
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Source: Google Maps, (2016)
9. Road Design and Planning
Manual Compliance
• Design life of 40 years
• Very limited applicable content
• Starting and termination points
for overtaking lanes on high
grades
• Sight Distance requirements
• Flood immunity for a Q100 flood
event
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Source: Department of Transport and Main Roads, (2013)
10. 2+1 Design Concerns
• A missing link on the Bruce Highway
• Minimum requirement for 13m wide
pavements
• Congestion at lane changeovers
• Potential for undesirable carriageway
operation and sight distance in
mountainous terrain
• Limited flood immunity
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Source: Google Maps, (2016)
11. Curra to Tinana Interchange 2+1
Cost Effectiveness
A Benefit Cost Ratio of 3.32 for a 2+1
design can be calculated
This is based on the implementation
of a 2+1 road reducing the fatality
rate by 50%
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Factor Value
Design Life 40 years
Annual Average Daily
Traffic (AADT)
10,000
Cost of Human Life $2,500,000
Road Length 62.4km
Construction Cost $4.3 million/km
Original Fatalities 0.2853/km
Predicted 0.1426/km
12. Conclusion and Recommendations
• Implement 2+1 Road from Curra to
the Tinana Interchange
• Widen the pavement to 13m
minimum to facilitate the 2+1
configuration
• Implement lane changeovers to meet
RPDM specifications and sight
distance requirements
• Provision of cable barrier
• The option for duplication in the
future is not impacted
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Source: National Roads Authority, (2004)